JPH04171724A - Semiconductor substrate cleaning method and device - Google Patents
Semiconductor substrate cleaning method and deviceInfo
- Publication number
- JPH04171724A JPH04171724A JP29712990A JP29712990A JPH04171724A JP H04171724 A JPH04171724 A JP H04171724A JP 29712990 A JP29712990 A JP 29712990A JP 29712990 A JP29712990 A JP 29712990A JP H04171724 A JPH04171724 A JP H04171724A
- Authority
- JP
- Japan
- Prior art keywords
- cleaning
- chemical solution
- droplets
- bubbles
- supplying
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004140 cleaning Methods 0.000 title claims description 155
- 239000000758 substrate Substances 0.000 title claims description 61
- 239000004065 semiconductor Substances 0.000 title claims description 38
- 238000000034 method Methods 0.000 title claims description 27
- 239000000126 substance Substances 0.000 claims description 89
- 229910021645 metal ion Inorganic materials 0.000 claims description 38
- 239000007789 gas Substances 0.000 claims description 18
- 239000004094 surface-active agent Substances 0.000 claims description 17
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 16
- 239000003960 organic solvent Substances 0.000 claims description 12
- 239000007787 solid Substances 0.000 claims description 10
- 229910052786 argon Inorganic materials 0.000 claims description 8
- 239000003463 adsorbent Substances 0.000 claims description 7
- 239000003795 chemical substances by application Substances 0.000 claims description 6
- 238000007599 discharging Methods 0.000 claims description 6
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims description 4
- 239000012530 fluid Substances 0.000 claims description 4
- 238000005192 partition Methods 0.000 claims description 2
- 239000000243 solution Substances 0.000 description 69
- 239000007788 liquid Substances 0.000 description 17
- 230000007547 defect Effects 0.000 description 9
- 229910001385 heavy metal Inorganic materials 0.000 description 9
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 8
- 239000013078 crystal Substances 0.000 description 8
- 150000002500 ions Chemical class 0.000 description 8
- 239000000356 contaminant Substances 0.000 description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 6
- 229910052802 copper Inorganic materials 0.000 description 6
- 239000010949 copper Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 5
- 239000006260 foam Substances 0.000 description 5
- 229910052710 silicon Inorganic materials 0.000 description 5
- 239000010703 silicon Substances 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 239000003990 capacitor Substances 0.000 description 4
- 230000005484 gravity Effects 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 238000010828 elution Methods 0.000 description 3
- 238000001459 lithography Methods 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000005406 washing Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 2
- 239000004809 Teflon Substances 0.000 description 2
- 229920006362 Teflon® Polymers 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 2
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 239000002699 waste material Substances 0.000 description 2
- QLOKJRIVRGCVIM-UHFFFAOYSA-N 1-[(4-methylsulfanylphenyl)methyl]piperazine Chemical compound C1=CC(SC)=CC=C1CN1CCNCC1 QLOKJRIVRGCVIM-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- JPVYNHNXODAKFH-UHFFFAOYSA-N Cu2+ Chemical compound [Cu+2] JPVYNHNXODAKFH-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 125000004429 atom Chemical group 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 229910001431 copper ion Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- YRIUSKIDOIARQF-UHFFFAOYSA-N dodecyl benzenesulfonate Chemical compound CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 YRIUSKIDOIARQF-UHFFFAOYSA-N 0.000 description 1
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 description 1
- 229940071161 dodecylbenzenesulfonate Drugs 0.000 description 1
- 125000001165 hydrophobic group Chemical group 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- -1 iron ions Chemical class 0.000 description 1
- 210000003127 knee Anatomy 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- KMUONIBRACKNSN-UHFFFAOYSA-N potassium dichromate Chemical compound [K+].[K+].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O KMUONIBRACKNSN-UHFFFAOYSA-N 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 150000003376 silicon Chemical class 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Landscapes
- Cleaning Or Drying Semiconductors (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
［産業上の利用分野１
本発明は、半導体基板の洗浄技術、特に半導体装置の特
性を劣化させる重金属等の汚染物質を除去することが可
能な半導体基板の洗浄技術に関するものである。
［従来の技術］
近年、半導体装置の集積度が向」ニするとともに絶縁膜
の薄膜化や接合のシャロー化が進行し、絶縁膜質や半導
体と＃＠縁膜との界面及び結晶欠陥の制御が重要な課題
となりつつある。そのため、半導体装置の製造工程にあ
っては、従来から注意が払われてきた粒子状の汚染物質
は勿論のこと、重金属等の原子状又は分子状汚染物質の
制御及び管理が必要となる。
しかし、フォトレジスト材料には、精製技術の限界その
他の原因により、クロム、鉄、ニッケル等の重金属が含
まれているので、リソグラフィー工程の際、これらの重
金属が汚染物質として半導体基板にどうしても付着する
。このため、半導体−３〜
基板は、リソグラフィー工程を施した後、必ず洗浄して
やる必要がある。従来の代表的な基板洗浄方法は、ＨＦ
、Ｈ２ＳＯ４、ＨＣＩ、ＨＮＯ，等の酸性溶液中や、Ｎ
Ｈ４ＯＨ及びＨ２Ｏ２の混合溶液中に基板を浸漬して汚
染物質を溶出させて除去するものである。なお、この種
の洗浄技術の詳細については２例えば、アール・シー・
ニー・レビュー（ＲＣＡ Ｒｅｖｊ、ｅｔｉ） ｐ、２
３４（１９７０）におけるＷｅｒｎｅｒ Ｋｅｒｎによ
る“Ｒａｄｊｏｃｈｅｍｉｃａｌ ５ｔｕｄｙ ｏｆ
Ｓｅｍ１ｃｏｎｄｕｃｔｏｒＳｕｒｆａｃｅ Ｃｏｎｔ
ａｍｉｎａｔｉｏｎ”と題する論文を参照されたい。
いずれにしても、従来の洗浄方法は、リソグラフィーの
工程において半導体基板に付着した重金属等を洗浄薬液
を用いて溶かして除去しようとするものである。一般に
、溶剤による金属物質の溶出は、水素の発生を伴うもの
であって、その現象を電気化学的に表現すると、次の式
のような形となる。
２Ｈ・＋２・−１２
７丁−Ｈ・ −−−−（２）
ここで、Ｍは金属原子、ＭＺ＋は溶出した金属イオン、
ｅは電子、Ｚはイオン価を示す。」二式において記号■
■■■をもって示した夫々の反応速度をｋｌ、 ｋ２．
ｋ３． ｋ４とすると、電子はそれ単独で洗浄薬液（
溶液）中に存在し得ないので、次式の関係が成立する。
ｚ （ｋｌ−ｋｚ）＋ ２ （ｋ４一に３）＝ ｏ −
−−・（３）（３）式から明白なように（ｋｌ一に２）
及び（ｋ４一に３）のどちらかは負の値となり、イオン
が消滅する方向に反応が進む。これを体系的に表した指
標がイオン化傾向である。一般に、ｋｌ、 ｋ２． ｋ
３． ｋ４のような反応速度の大きさは、イオン濃度及
び電極電位、換言すれば、固体と薬液との間の電位差に
よって定まる。イオン化傾向は、イオン化反応が優勢に
起こる電極電位を比較したものである。例えば銅は、イ
オン化の傾向が水素より遥かに小さいため、（ｋｌ一に
２）の値が負になってしまう。そのため、洗浄によって
半導体基板から銅を除去しようとしでも、薬液中の微量
な銅イオンがかえって半導体基板に付着してしまうとい
う問題が生ずる。
もっとも、イオン化が比較的容易に起こり得る金属であ
っても、その反応速度は、前述したように電極電位と洗
浄薬液中の金属イオン濃度とによって左右される。電極
電位は、薬液中のイオンが固体表面に付着することによ
って生ずるものであるから、反応速度は、固体物質と溶
液との組合せによって変化し、必ずしも速やかな反応が
発生するとは限らない。結果として長時間の洗浄が必要
となる。しかも、固体表面に付着したイオンの外側は、
反対電荷のイオン濃度が高くなり、結果として固体と溶
液の界面に一種のコンデンサが形成される。これを電気
二重層という。このため、溶出した金属イオン濃度が上
記電気二重層内で高くなると、イオン化反応が制限され
、当該金属イオンが半導体基板上に再び付着してしまい
、有効な除去が出来ないという別の問題も生ずる。
要するに、従来の洗浄方法は、■重金属の種類によって
は殆ど除去することが出来ない■長時間に亘る洗浄が必
要である■溶出した金属が再び半導体基板に付着する等
の問題があった。[Industrial Application Field 1] The present invention relates to a semiconductor substrate cleaning technique, and particularly to a semiconductor substrate cleaning technique capable of removing contaminants such as heavy metals that deteriorate the characteristics of a semiconductor device. [Prior art] In recent years, as the degree of integration of semiconductor devices has improved, insulating films have become thinner and junctions have become shallower, and the quality of insulating films, the interface between semiconductors and #@ edge films, and the control of crystal defects have improved. This is becoming an important issue. Therefore, in the manufacturing process of semiconductor devices, it is necessary to control and manage not only particulate contaminants, which have traditionally been taken care of, but also atomic or molecular contaminants such as heavy metals. However, due to limitations in purification technology and other causes, photoresist materials contain heavy metals such as chromium, iron, and nickel, so these heavy metals inevitably adhere to semiconductor substrates as contaminants during the lithography process. . Therefore, it is necessary to clean the semiconductor substrate after performing the lithography process. The typical conventional substrate cleaning method is HF
, H2SO4, HCI, HNO, etc., or N
The substrate is immersed in a mixed solution of H4OH and H2O2 to elute and remove contaminants. For details on this type of cleaning technology, see 2, for example, R.C.
Knee Review (RCA Revj, eti) p, 2
34 (1970) by Werner Kern, “Radjochemical 5 study of
Sem1conductorSurface Cont
In any case, conventional cleaning methods attempt to remove heavy metals and the like that have adhered to semiconductor substrates during the lithography process by dissolving them using cleaning chemicals.Generally, The elution of metal substances by a solvent is accompanied by the generation of hydrogen, and the electrochemical expression of this phenomenon is as follows: 2H・+2・−12 7-H・− ---(2) Here, M is a metal atom, MZ+ is an eluted metal ion,
e represents an electron, and Z represents an ionic valence. ” In the second formula, the symbol ■
The respective reaction rates indicated by ■■■ are kl, k2.
k3. Assuming k4, the electrons alone are in the cleaning chemical solution (
solution), the following relationship holds true: z (kl-kz) + 2 (k4 to 3) = o -
---(3) As is clear from equation (3) (kl - 2)
Either of or (k4 - 3) becomes a negative value, and the reaction progresses in the direction of annihilation of the ions. An index that systematically expresses this is the ionization tendency. In general, kl, k2. k
3. The magnitude of the reaction rate, such as k4, is determined by the ion concentration and electrode potential, in other words, the potential difference between the solid and the chemical solution. Ionization tendency is a comparison of electrode potentials at which ionization reactions occur predominantly. For example, copper has a much smaller tendency to ionize than hydrogen, so the value of (kl - 2) becomes negative. Therefore, even if an attempt is made to remove copper from the semiconductor substrate by cleaning, a problem arises in that trace amounts of copper ions in the chemical solution end up adhering to the semiconductor substrate. However, even for metals that can be ionized relatively easily, the reaction rate depends on the electrode potential and the metal ion concentration in the cleaning chemical solution, as described above. Since the electrode potential is generated when ions in the chemical solution adhere to the solid surface, the reaction rate changes depending on the combination of the solid substance and the solution, and a rapid reaction does not necessarily occur. As a result, long cleaning times are required. Moreover, the outside of the ions attached to the solid surface is
The concentration of ions of opposite charge increases, resulting in the formation of a kind of capacitor at the solid-solution interface. This is called an electric double layer. For this reason, when the concentration of eluted metal ions increases within the electric double layer, the ionization reaction is restricted and the metal ions re-adhere to the semiconductor substrate, causing another problem in that they cannot be effectively removed. . In short, conventional cleaning methods have problems such as: (Depending on the type of heavy metal, it is hardly possible to remove it.) (2) It requires cleaning for a long time. (2) The eluted metal adheres to the semiconductor substrate again.
【発明が解決しようとする課題１
本発明は、前述した従来技術の問題点を全て解消し、洗
浄薬液中に溶出した金属イオンを効率的に排除すること
が可能な半導体基板の洗浄方法及びそのための装置を提
案することを目的とするものである。
【課題を解決するための手段］
」二記課題は、半導体基板を薬液中に浸゛漬して洗浄を
行なう際、微細な気泡又は液滴を基板近傍の洗浄薬液中
に供給し、同薬液中に溶出した金属イオンを当該気泡又
は液滴の表面又は内部に担持させて浮上又は沈降させる
ことによって解決することが出来る。
気泡又は液滴は、洗浄薬液に対して実質的に不活性かつ
不溶性である流体（気体又は液体）をもって形成するこ
とが必要である。何故ならば、洗浄薬液と反応し或は洗
浄薬液に溶ける流体を用いたのでは、当該薬液中に微細
な気泡又は液滴を形成することが出来ないからである。
本発明者等の実験によれば、洗浄薬液として１％弗酸水
溶液を使用する場合、気体では例えばアルゴンガス、液
体では例えばカルボン酸系の有機溶剤を使用することに
よって良好な結果を得ることが出来た。
なお、気泡又は液滴は、洗浄薬液との間の比重の差を利
用して浮上又は沈降させるものであるから、気体の場合
は基板下側の洗浄薬液中に気泡を供給し、液体の場合は
当該液体の比重に応じて基板上側又は下側のいずれか一
方の洗浄薬液中に液滴を供給することが必要である。
【作用】
半導体基板を洗浄する場合、当該基板に付着していた重
金属等は、金属イオンの形で洗浄薬液中に溶出する。こ
の状態の洗浄薬液に対して微細な気泡又は液滴を供給す
ると、薬液中に溶出した金属イオンは、熱力学的な安定
性の差により、気泡の表面に付着するか、液滴の内部に
溶は込む。また、成る種の有機溶剤を用いた場合は、薬
液中に溶出した金属イオンは、当該有機溶剤と反応して
錯体を作り、液滴の内部に取り込まれる。
このようにして気泡又は液滴に担持された金属イオンは
、当該気泡又は液滴と共に薬液中を浮一に又は沈降する
。従って、浮上又は沈殿した気泡又は液滴を洗浄槽から
排出することにより、好ましくない金属イオンを洗浄薬
液中から除去することが出来る。特に本発明の場合は、
半導体基板の極めて近傍に気泡又は液滴を通過させるこ
とが可能であるから、基板周囲の金属イオンを瞬時に除
去することがで、き、その後の金属イオンの溶出を効率
良く促進させることが可能となる。溶出した金属イオン
が再び基板表面に付着することもない。
気泡又は液滴による金属イオンの担持をより効果的にす
るには、界面活性剤を洗浄薬液中に添加することが望ま
しい。界面活性剤は、疎水基を気泡（又は液滴）の内部
方向に配向して気泡（又は液滴）と洗浄薬液との界面に
付着する。このため、界面活性剤が付着した気泡（又は
液滴）が洗浄中の半導体基板の近傍を通過すると、基板
表面での電気的平衡状態が崩れて電気二重層構造が乱れ
る結果、界面活性剤の親木基（負イオン）と半導体基板
から溶出した金属イオン（正イオン）との間で強力な静
電気的結合が形成される。
更に、洗浄薬液中に金属イオンの硫化剤（例えば硫化水
素）を添加しておくと、半導体基板から溶出した金属イ
オンが当該硫化剤と反応して硫化物となる。この硫化物
は、溶解度積が非常に小さく、通常は固体のままの状態
で薬液中に存在するため、気泡又は液滴に対する付着が
更に容易となり、金属イオンの除去効率をより向上させ
ることが出来る。
また、洗浄薬液中には、金属イオンの固体吸着剤（例え
ば０．１ｍｎ程度の粒径のグラファイト粒子）を分散さ
せて添加しておくことが望ましい。この種の吸着剤は、
洗浄薬液自体に含まれている好ましくない不純物を吸着
して同薬液を清浄にするほか、半導体基板近傍の金属イ
オンを捕獲して同部分のイオン濃度を低下させる効果が
ある。不純物や金属イオンを捕獲した吸着剤は、やはり
気泡又は液滴に付着して浮上又は沈降する。
〈実験結果〉
本発明者等は、気泡又は液滴による金属イオン除去効果
を確認するため、重金属を溶解させた実験用洗浄薬液（
体積濃度］Ｏｐｐｍの銅を溶解させた１％弗酸水溶液）
中にシリコン基板を約１時間浸漬して故意に汚染した後
、本発明の洗浄実験を行なって見た。
洗浄実験は、故意に汚染したシリコン基板を洗浄槽の内
部に装填した後、所定量の清浄な実験用洗浄薬液を洗浄
槽に供給することによって行な、った。そして、洗浄の
結果として薬液中に溶出する金属イオンを捕捉して分離
するため、シリコン基板の下側から洗浄薬液中にアルゴ
ンガスの微細な気泡を供給した。アルゴンガスの気泡は
、平均孔径が約１μｍの多孔質板を用いて発生させた。
なお、気泡に対する金属イオンの吸着効果を高めるため
、洗浄時間中、ドデシルベンゼンスルホン酸すＩ・リウ
ムを０ 、２ｐｐｍ含有する界面活性剤（水溶液）を洗
浄薬液中に絶えず供給した。アルゴンガスの供給量は、
洗浄槽からオーバーフローする液量が一］］−
洗浄薬液の供給量及び界面活性剤の供給量の和に等しく
なるように調整した。
実験を開始すると、アルゴンガスの気泡が比重差によっ
て洗浄薬液中を移動して金属イオンを吸着し、泡沫とな
って液面上に浮上した。この泡沫は、洗浄槽上部の内壁
に接して次々と消滅し、その結果として生じた廃液が洗
浄槽からオーバーフローした。洗浄完了後、界面活性剤
の供給を止めたところ、５分程度で泡沫の発生が停止し
た。この結果、洗浄薬液中に供給した界面活性剤が金属
イオンと共に気泡に付着して浮上していることが判明し
た。界面活性剤を除去する目的で洗浄薬液の供給量を増
加し、同薬液がオーバーフローする状態で５分間追加洗
浄を行なった後、槽内の薬液を全部抜き取り、シリコン
基板が乾燥するのを待って外部に取り出した。
一方、比較用データを得るため、上記実験の際に同時に
汚染したシリコン基板を使用し、同じ洗浄薬液を用いて
従来方法による洗浄実験を行なって見た。洗浄の完了後
、純水を収容した別の石英製洗浄槽内にシリコン基板を
１０分間浸漬して取り出し、窒素雰囲気中で乾燥した。
洗浄効果を比較するため、本発明の洗浄方法による基板
及び従来の洗浄方法による基板の双方を１０００℃の酸
素雰囲気中で１２時間に亘って熱処理を施し、銅汚染に
起因する結晶欠陥を基板中に発生させた。更に、クロム
酸カリウム（Ｋ２Ｃｒ２Ｏ７）及び弗酸の混合溶液を用
いて両基板の結晶欠陥を選択的にエツチングし、顕微鏡
を用いて結晶欠陥の観察を行った。また、両基板の表面
に複数個のＭＯＳ （Ｍｅｔａｌ ＯｘｉｄｅＳｅｍｉ
ｃｏｎｄｕｃｔｏｒ）型キャパシタを作成し、そのグー
１−電極に電圧を印加してゲート酸化膜が破壊する電圧
を測定した。
測定の結果を第３図に示す。同図の横軸は洗浄時間、縦
軸は結晶欠陥の発生密度である。どちらの洗浄方法を用
いた場合でも、洗浄時間が長くなればなる程、結晶欠陥
の発生密度が低減する。しかし、本発明の方法による場
合は、洗浄時間が５分を超えると、検出可能な限界（１
０３個／ｃｍ２）以下まで結晶欠陥の発生密度が低下し
た。これに対し、従来方法による場合は、清浄時間が１
時間を超えても、１０４個／ｃｍ２程度の密度で結晶欠
陥が発生した。即ち、本発明の方法によれば、極めて短
時間に微量の銅まで除去することが出来る。
第４図は、両方法による洗浄時間を１５分に設定し、Ｍ
ＯＳキャパシタのゲート酸化膜破壊電圧を比較した結果
である。本図は、同一基板内で２５個のキャパシタを測
定した結果である。同図から明らかなように、本発明の
洗浄方法を用いた場合には、ゲート酸化膜の破壊個数を
非常に少なくすることができ、ゲート酸化膜の信頼性を
高めることが可能となる。Problem 1 to be Solved by the Invention The present invention provides a method for cleaning a semiconductor substrate, which solves all of the problems of the prior art described above, and is capable of efficiently eliminating metal ions eluted into a cleaning chemical solution, and a cleaning method therefor. The purpose is to propose a device for this purpose. [Means for solving the problem] The second problem is that when cleaning a semiconductor substrate by immersing it in a chemical solution, fine bubbles or droplets are supplied into the cleaning chemical solution near the substrate, and the chemical solution This problem can be solved by supporting the metal ions eluted inside or on the surface or inside of the bubbles or droplets and causing them to float or settle. It is necessary that the bubbles or droplets be formed with a fluid (gas or liquid) that is substantially inert and insoluble in the cleaning chemical solution. This is because if a fluid that reacts with or dissolves in the cleaning chemical solution is used, fine bubbles or droplets cannot be formed in the cleaning chemical solution. According to experiments conducted by the present inventors, when using a 1% hydrofluoric acid aqueous solution as a cleaning chemical solution, good results can be obtained by using, for example, argon gas as a gas or a carboxylic acid-based organic solvent as a liquid. done. Note that air bubbles or droplets float or sink using the difference in specific gravity between them and the cleaning chemical solution, so if they are a gas, the bubbles are supplied into the cleaning chemical solution below the substrate, and if they are a liquid, they are caused to float or sink. It is necessary to supply droplets into the cleaning chemical solution on either the upper side or the lower side of the substrate depending on the specific gravity of the liquid. [Operation] When cleaning a semiconductor substrate, heavy metals, etc. attached to the substrate are eluted into the cleaning chemical solution in the form of metal ions. When fine bubbles or droplets are supplied to the cleaning chemical solution in this state, the metal ions eluted into the chemical solution will either adhere to the surface of the bubbles or be trapped inside the droplets due to the difference in thermodynamic stability. Melt goes in. In addition, when a certain type of organic solvent is used, the metal ions eluted into the chemical solution react with the organic solvent to form a complex, which is taken into the inside of the droplet. The metal ions supported on the bubbles or droplets float or settle in the chemical solution together with the bubbles or droplets. Therefore, by discharging floating or precipitated bubbles or droplets from the cleaning tank, undesirable metal ions can be removed from the cleaning chemical solution. Especially in the case of the present invention,
Since it is possible to pass bubbles or droplets very close to the semiconductor substrate, metal ions around the substrate can be instantly removed, and subsequent elution of metal ions can be efficiently promoted. becomes. The eluted metal ions will not adhere to the substrate surface again. In order to make the metal ions supported by bubbles or droplets more effective, it is desirable to add a surfactant to the cleaning chemical solution. The surfactant attaches to the interface between the bubble (or droplet) and the cleaning chemical solution with its hydrophobic group oriented toward the inside of the bubble (or droplet). Therefore, when bubbles (or droplets) with surfactant attached pass near the semiconductor substrate being cleaned, the electrical equilibrium state on the substrate surface is disrupted and the electric double layer structure is disturbed, resulting in the surfactant A strong electrostatic bond is formed between the parent wood group (negative ions) and the metal ions (positive ions) eluted from the semiconductor substrate. Furthermore, when a metal ion sulfiding agent (for example, hydrogen sulfide) is added to the cleaning chemical solution, the metal ions eluted from the semiconductor substrate react with the sulfiding agent to become sulfide. This sulfide has a very small solubility product and is usually present in the chemical solution in a solid state, so it can more easily adhere to bubbles or droplets and improve the removal efficiency of metal ions. . Further, it is desirable to disperse and add a solid adsorbent for metal ions (for example, graphite particles having a particle size of about 0.1 mm) to the cleaning chemical solution. This kind of adsorbent is
In addition to cleaning the cleaning chemical by adsorbing undesirable impurities contained in the cleaning chemical, it also has the effect of capturing metal ions near the semiconductor substrate and reducing the ion concentration there. The adsorbent that has captured impurities and metal ions also adheres to bubbles or droplets and floats or settles. <Experimental Results> In order to confirm the metal ion removal effect of bubbles or droplets, the present inventors prepared an experimental cleaning chemical solution in which heavy metals were dissolved (
Volume concentration] 1% hydrofluoric acid aqueous solution in which copper of Oppm was dissolved)
A cleaning experiment of the present invention was conducted after intentionally contaminating a silicon substrate by immersing it in the solution for about an hour. The cleaning experiment was conducted by loading an intentionally contaminated silicon substrate into a cleaning tank and then supplying a predetermined amount of a clean experimental cleaning chemical solution to the cleaning tank. Then, in order to capture and separate metal ions eluted into the chemical solution as a result of cleaning, fine bubbles of argon gas were supplied into the cleaning chemical solution from below the silicon substrate. Argon gas bubbles were generated using a porous plate with an average pore size of about 1 μm. In order to enhance the adsorption effect of metal ions on bubbles, a surfactant (aqueous solution) containing 0.2 ppm of I.lium dodecylbenzenesulfonate was constantly supplied to the cleaning chemical solution during the cleaning period. The amount of argon gas supplied is
The amount of liquid overflowing from the cleaning tank was adjusted to be equal to the sum of the amount of cleaning chemical solution supplied and the amount of surfactant supplied. When the experiment started, argon gas bubbles moved through the cleaning solution due to the difference in specific gravity, adsorbed metal ions, and floated to the surface of the solution as foam. This foam contacted the inner wall of the upper part of the washing tank and disappeared one after another, and the resulting waste liquid overflowed from the washing tank. After the cleaning was completed, the supply of surfactant was stopped, and the generation of foam stopped in about 5 minutes. As a result, it was found that the surfactant supplied in the cleaning chemical solution adhered to the bubbles together with metal ions and floated to the surface. In order to remove the surfactant, the amount of cleaning chemical solution supplied was increased, and after additional cleaning was performed for 5 minutes with the chemical solution overflowing, all the chemical solution in the tank was removed and the silicon substrate was allowed to dry. I took it outside. On the other hand, in order to obtain data for comparison, a cleaning experiment was conducted using a conventional method using a silicon substrate contaminated at the same time as in the above experiment and using the same cleaning chemical solution. After the cleaning was completed, the silicon substrate was immersed in another quartz cleaning tank containing pure water for 10 minutes, taken out, and dried in a nitrogen atmosphere. In order to compare the cleaning effects, both substrates prepared by the cleaning method of the present invention and substrates prepared by the conventional cleaning method were heat treated in an oxygen atmosphere at 1000°C for 12 hours to remove crystal defects caused by copper contamination in the substrates. It was caused to occur. Furthermore, crystal defects in both substrates were selectively etched using a mixed solution of potassium chromate (K2Cr2O7) and hydrofluoric acid, and the crystal defects were observed using a microscope. In addition, multiple MOS (Metal Oxide Semi)
A conductor-type capacitor was prepared, a voltage was applied to the electrode, and the voltage at which the gate oxide film was destroyed was measured. The measurement results are shown in Figure 3. In the figure, the horizontal axis represents the cleaning time, and the vertical axis represents the density of occurrence of crystal defects. Regardless of which cleaning method is used, the longer the cleaning time, the lower the density of crystal defects. However, when using the method of the present invention, if the washing time exceeds 5 minutes, the detectable limit (1
The density of crystal defects decreased to 0.03 pieces/cm2) or less. In contrast, when using the conventional method, the cleaning time is 1
Even after a long period of time, crystal defects were generated at a density of about 10 4 defects/cm 2 . That is, according to the method of the present invention, even trace amounts of copper can be removed in an extremely short time. Figure 4 shows the cleaning time for both methods set to 15 minutes, and the M
These are the results of comparing the gate oxide film breakdown voltages of OS capacitors. This figure shows the results of measuring 25 capacitors on the same board. As is clear from the figure, when the cleaning method of the present invention is used, the number of broken gate oxide films can be greatly reduced, and the reliability of the gate oxide film can be improved.
【実施例１
以下、本発明を図面に示した実施例を参照して更に詳細
に説明する。
〈実施例１〉
第１図は、金属イオン回収のための担体として気泡を使
用した場合の洗浄装置の一例である。本実施例の場合、
洗浄槽１０は、テフロンをもって構成され、かつ、上下
二つの部分（上部１０ａ及び下部１０ｂ）に分割可能な
構造となっている。洗浄槽下部１０ｂの内部は、微細な
気泡を発生して槽内に供給するためのフィルタとして機
能する多孔質板１１によって上下に仕切られている。当
該多孔質板は、平均孔径が１μｍ程度のものを使用した
。被洗浄物である半導体基板１２は、適当な治具１３に
装着した状態で多孔質板１１上に装填する。
洗浄槽下部１０ｂの中間部（多孔質板１１の上側部分）
には、テフロン製の３個の配管１４〜１６が配設されて
いる。配管１４は、洗浄薬液を供給するためのものであ
って、その他端は、制御弁１７及びポンプ１８を介して
溶液調整槽１９に連結されている。配管１５は、洗浄薬
液に界面活性剤（水溶液）を添加するためのものであっ
て、その他端は、制御弁２０及びポンプ２１を介して別
の溶液調整槽２２に連結されている。また、配管１６は
、洗浄槽１０内から洗浄薬液を排出するためのものであ
って、開閉制御弁２３を備えている。
更に、洗浄槽下部１０ｂの底部には、不活性かつ不溶性
の気体（例えばアルゴンガス）を洗浄槽１０に供給する
ための配管２４が配設されており、その他端は、制御弁
２５を介してガスボンベ２６に連結されている。なお、
洗浄槽上部１０ａの上端には、オーバーフロー用のドレ
イン２７が配設されている。
半導体基板１２の洗浄に当っては、先ず制御弁２５を開
け、ガスボンベ２６からの気体が洗浄槽１０を通過する
ようにした後、洗浄槽上部１０ａを同槽下部１０ｂから
取り外し、半導体基板１２を装着した治具１３を洗浄槽
下部１０ｂ内に装填する。次に、洗浄槽上部１０ａを洗
浄槽下部１０ｂに取り付けた後、洗浄薬液用のポンプ１
８を始動させ、制御弁１７を開けて溶液調整槽１９に貯
蔵しておいた洗浄薬液（例えば弗酸水溶液）を洗浄槽１
０内に供給する。洗浄薬液が液面基準線２８まで達した
後、界面活性剤用のポンプ２１を始動させ、制御弁２０
を開けて界面活性剤（例えばドデシルベンゼンスルホン
酸ナトリウム溶液）を洗浄槽１０内に供給する。
ガスボンベ２６からの気体は、多孔質板１１を通過する
ことによって直径１μｍ程度の多量の気泡２９となり、
半導体基板１２の近傍の洗浄薬液中を通過＝１６−
し、同部分に存在する金属イオンを捕捉して浮上する。
この結果、液面基準線２８より上の部分に多量の泡沫が
発生することとなる。この泡沫は、洗浄槽上部１０ａの
内壁と接することによって順次消滅して廃液となり、オ
ーバーフロー用ドレイン２７から外部に排出される。排
出液量は、不活性ガス及び界面活性剤溶液の供給量を加
減することによって制御することが可能である。
一定時間経過後、制御弁２０を閉じてポンプ２１を止め
、界面活性剤の供給を停止する。この状態で基板の洗浄
を暫く続けて薬液表面に泡沫が発生しないことを確認し
た後、洗浄薬液の供給量を増加せしめて当該薬液をオー
バーフローさせる。最後に、制御弁１７を閉じてポンプ
１８を止め、洗浄薬液の供給を停止した後、制御弁２３
を開けて洗浄槽ｌＯ内部の薬液を全部排出し、半導体基
板１２の乾燥を待って同基板を取り出す。
本実施例では、洗浄薬液中に気泡を発生させるために仕
切板兼用の多孔質板１１を使用したが、例えば多孔質板
を先端に取り付けたノズルを洗浄槽１０の内部の適当な
場所に配置し、当該ノズルに気体を供給することによっ
ても同様の目的を達成することが可能である。また、調
整槽１９内の洗浄薬液には、必要に応じて金属イオンの
硫化剤（例えば硫化水素）を微量添加し、或は、金属イ
オンの固体吸着剤（例えばグラファイト粒子）を分散さ
せて添加することも可能である。但し、固体吸着剤を使
用する場合は、ポンプ１８としてスラッジポンプを使用
することが望ましい。
〈実施例２〉
第２図は、金属イオン回収のための担体として液滴を使
用した場合の一実施例である。本実施例の場合は、半導
体基板３０を装着した治具３１を洗浄槽３２の底部に装
填する。洗浄槽３２には、３個の配管３３〜３５が配設
されている。配管３３は、洗浄薬液を洗浄槽３２に供給
するためのものであって、その他端は、制御弁３６及び
ポンプ３７を介して溶液調整槽３８に連結されている。
配管３４は、液滴を形成するための液体（例えば有機溶
剤）を洗浄槽３２に供給するためのものであって、洗浄
槽３２内への延長部分を有しており、同部分は、半導体
基板３０の」−側に位置するように配設され、かつ、直
径０．１ｍｍ程度の多数の孔３９が設けられている。配
管３４の他端は、制御弁４０及びポンプ４１２介して別
の溶液調整槽４２に連結されている。なお、配管３５は
、洗浄薬液に対して不活性な液体及び洗浄薬液を排出す
るためのものであって、開閉制御弁４３を備えている。
半導体基板３０の洗浄に当っては、先ず、制御方４ｏを
開けてポンプ４１を動作させ、洗浄槽３２の内部に液滴
用の液体を供給する。当該液体の液面が槽内底部の排出
用配管３５よりも少し高くなったところで液体の供給を
一時を停止する。次に、制御弁３６を開けてポンプ３７
を動作させ、洗浄薬液を洗浄槽内３２に供給する。本実
施例の場合は、液滴用の液体として、洗浄薬液よりも比
重が重い有機溶剤を使用しているため、当該有機溶剤は
、洗浄薬液と分離して洗浄槽３２の底部に溜る性質があ
る。
この状態で再び制御弁４０を開けてポンプ４１を動作さ
せると、有機溶剤は、直径０．３ｍｍ程度の液滴４４と
なって洗浄薬液中を沈降して半導体基板３０の近傍を通
過し、その際、同基板から溶出した金属イオンを捕捉す
る。洗浄槽３２の底部に溜った余分の有機溶剤は、制御
弁４３を操作することによって適宜排出する。一定時間
の洗浄後、半導体基板３０を取り出して窒素雰囲気中で
乾燥する。本実施例では、カルボン酸系の有機溶剤を用
いたが、同溶剤は、銅、ニッケル、鉄イオンの除去に特
に効果的に機能する。
【発明の効果】
本発明は、気泡又は液滴の吸着作用を利用して洗浄薬液
中の金属イオンを捕捉するものであるため、半導体基板
と洗浄薬液との界面における金属イオン濃度を常に極め
て小さくすることが可能となり、金属イオンの溶出を容
易化することが出来る。このため、汚染物質、特に重金
属等の除去を短時間で効果的に行うことができ、また、
溶出した汚染物質が半導体基板上に再び付着することを
防止することが出来る。Embodiment 1 The present invention will be described in more detail below with reference to embodiments shown in the drawings. <Example 1> FIG. 1 is an example of a cleaning device in which air bubbles are used as a carrier for recovering metal ions. In the case of this example,
The cleaning tank 10 is made of Teflon and has a structure that can be divided into two upper and lower parts (an upper part 10a and a lower part 10b). The inside of the lower part 10b of the cleaning tank is partitioned into upper and lower parts by a porous plate 11 that functions as a filter for generating fine air bubbles and supplying them into the tank. The porous plate used had an average pore diameter of about 1 μm. A semiconductor substrate 12, which is an object to be cleaned, is mounted on a suitable jig 13 and loaded onto the porous plate 11. Middle part of cleaning tank lower part 10b (upper part of porous plate 11)
Three pipes 14 to 16 made of Teflon are arranged. The piping 14 is for supplying a cleaning chemical solution, and the other end is connected to a solution adjustment tank 19 via a control valve 17 and a pump 18. The piping 15 is for adding a surfactant (aqueous solution) to the cleaning chemical solution, and the other end is connected to another solution adjustment tank 22 via a control valve 20 and a pump 21. Further, the pipe 16 is for discharging the cleaning chemical solution from inside the cleaning tank 10, and is provided with an opening/closing control valve 23. Furthermore, a pipe 24 for supplying an inert and insoluble gas (for example, argon gas) to the cleaning tank 10 is arranged at the bottom of the lower part 10b of the cleaning tank, and the other end is connected to the cleaning tank 10 via a control valve 25. It is connected to a gas cylinder 26. In addition,
A drain 27 for overflow is provided at the upper end of the cleaning tank upper part 10a. When cleaning the semiconductor substrate 12, first open the control valve 25 to allow gas from the gas cylinder 26 to pass through the cleaning tank 10, then remove the upper part 10a of the cleaning tank from the lower part 10b of the tank, and remove the semiconductor substrate 12. The mounted jig 13 is loaded into the lower part 10b of the cleaning tank. Next, after attaching the upper part 10a of the cleaning tank to the lower part 10b of the cleaning tank, the pump 1 for cleaning chemical solution is
8, the control valve 17 is opened, and the cleaning chemical solution (for example, a hydrofluoric acid aqueous solution) stored in the solution adjustment tank 19 is poured into the cleaning tank 1.
Supply within 0. After the cleaning chemical reaches the liquid level reference line 28, the surfactant pump 21 is started, and the control valve 20 is activated.
is opened and a surfactant (eg, sodium dodecylbenzenesulfonate solution) is supplied into the cleaning tank 10. The gas from the gas cylinder 26 becomes a large amount of bubbles 29 with a diameter of about 1 μm by passing through the porous plate 11.
It passes through the cleaning chemical near the semiconductor substrate 12 (=16-), traps metal ions present in the same area, and floats up. As a result, a large amount of foam is generated above the liquid level reference line 28. The foam gradually disappears as it comes into contact with the inner wall of the upper part 10a of the cleaning tank and becomes waste liquid, which is discharged to the outside from the overflow drain 27. The amount of liquid discharged can be controlled by adjusting the amounts of inert gas and surfactant solution supplied. After a certain period of time has elapsed, the control valve 20 is closed, the pump 21 is stopped, and the supply of surfactant is stopped. After continuing to clean the substrate in this state for a while and confirming that no bubbles are generated on the chemical surface, the supply amount of the cleaning chemical is increased to cause the chemical to overflow. Finally, after closing the control valve 17 and stopping the pump 18 to stop the supply of cleaning chemicals, the control valve 23
The cleaning tank IO is opened, all of the chemical solution inside the cleaning tank IO is discharged, the semiconductor substrate 12 is waited for to dry, and then the same substrate is taken out. In this embodiment, a porous plate 11 which also serves as a partition plate is used to generate air bubbles in the cleaning chemical solution. However, the same objective can also be achieved by supplying gas to the nozzle. Additionally, a small amount of a metal ion sulfiding agent (for example, hydrogen sulfide) or a dispersed metal ion solid adsorbent (for example, graphite particles) may be added to the cleaning chemical solution in the adjustment tank 19 as necessary. It is also possible to do so. However, when using a solid adsorbent, it is desirable to use a sludge pump as the pump 18. <Example 2> FIG. 2 is an example in which a droplet is used as a carrier for recovering metal ions. In the case of this embodiment, the jig 31 with the semiconductor substrate 30 mounted thereon is loaded into the bottom of the cleaning tank 32. The cleaning tank 32 is provided with three pipes 33 to 35. The piping 33 is for supplying a cleaning chemical solution to the cleaning tank 32 , and the other end is connected to a solution adjustment tank 38 via a control valve 36 and a pump 37 . The piping 34 is for supplying a liquid (for example, an organic solvent) for forming droplets to the cleaning tank 32, and has an extension part into the cleaning tank 32, and this part is for supplying a liquid (for example, an organic solvent) for forming droplets. It is arranged so as to be located on the "-" side of the substrate 30, and has a large number of holes 39 each having a diameter of about 0.1 mm. The other end of the pipe 34 is connected to another solution adjustment tank 42 via a control valve 40 and a pump 412. Note that the pipe 35 is for discharging a liquid inert to the cleaning chemical and the cleaning chemical, and is provided with an opening/closing control valve 43. When cleaning the semiconductor substrate 30, first, the control means 4o is opened and the pump 41 is operated to supply droplet liquid to the inside of the cleaning tank 32. When the level of the liquid becomes slightly higher than the discharge pipe 35 at the bottom of the tank, the supply of the liquid is temporarily stopped. Next, open the control valve 36 and pump 37.
is operated to supply the cleaning chemical solution into the cleaning tank 32. In the case of this embodiment, since an organic solvent having a higher specific gravity than the cleaning chemical solution is used as the droplet liquid, the organic solvent has a tendency to separate from the cleaning chemical solution and accumulate at the bottom of the cleaning tank 32. be. When the control valve 40 is opened again in this state and the pump 41 is operated, the organic solvent becomes droplets 44 with a diameter of about 0.3 mm, settles in the cleaning chemical solution, passes near the semiconductor substrate 30, and At this time, metal ions eluted from the substrate are captured. Excess organic solvent accumulated at the bottom of the cleaning tank 32 is appropriately discharged by operating the control valve 43. After cleaning for a certain period of time, the semiconductor substrate 30 is taken out and dried in a nitrogen atmosphere. In this example, a carboxylic acid-based organic solvent was used, and this solvent functions particularly effectively in removing copper, nickel, and iron ions. Effects of the Invention Since the present invention captures metal ions in a cleaning chemical solution by utilizing the adsorption effect of air bubbles or droplets, the metal ion concentration at the interface between the semiconductor substrate and the cleaning chemical solution can always be kept extremely low. This makes it possible to facilitate the elution of metal ions. Therefore, contaminants, especially heavy metals, etc. can be removed effectively in a short time, and
It is possible to prevent the eluted contaminants from adhering to the semiconductor substrate again.
第１図及び第２図は、本発明に係る半導体基板の洗浄装
置の異なる実施例を示す概略図、第３図及び第４図は、
本発明に係る洗浄方法の実験結果を示す特性図である。
〈符号の説明〉
１０・・・洗浄槽、１１・多孔質板、１２・・・半導体
基板、１３・・・基板装着用治具、１４・洗浄薬液供給
用配管、１５・・界面活性剤供給用配管、１６・溶液排
出用配管、２４・・・気泡供給用配管、２７・・オーバ
ーフロー用ドレイン、２９・・・気泡、３０・・・半導
体基板、３Ｉ・・・基板装着用治具、３２・・・洗浄槽
、３３・・・洗浄薬液供給用配管、３４・・・液滴供給
用配管、３５・・・溶液排出用配管、４４・・・液滴。
代理人 弁理士 薄 １）利 幸
ゲート電圧（Ｖ）
一１１’；ｔｎ−FIGS. 1 and 2 are schematic diagrams showing different embodiments of the semiconductor substrate cleaning apparatus according to the present invention, and FIGS. 3 and 4 are
FIG. 3 is a characteristic diagram showing experimental results of the cleaning method according to the present invention. <Explanation of symbols> 10...Cleaning tank, 11.Porous plate, 12...Semiconductor substrate, 13...Jig for mounting substrate, 14.Piping for supplying cleaning chemical solution, 15..Surfactant supply Piping for use, 16. Piping for solution discharge, 24. Piping for supplying air bubbles, 27.. Drain for overflow, 29.. Air bubbles, 30.. Semiconductor substrate, 3I.. Jig for mounting substrate, 32. ...Cleaning tank, 33... Piping for supplying cleaning chemical solution, 34... Piping for supplying droplets, 35... Piping for discharging solution, 44... Droplets. Agent Patent attorney Susuki 1) Toshiyuki Gate voltage (V) 111';tn-
Claims (1)
該薬液に対して実質的に不活性かつ不溶性の流体からな
る微細な気泡又は液滴を基板近傍の薬液中に供給し、同
薬液中に溶出した金属イオンを当該気泡又は液滴に担持
させて浮上又は沈降させることにより、洗浄薬液中の金
属イオンを分離して排出すること特徴とする洗浄方法。 ２、アルゴンガスからなる気泡を洗浄薬液中に供給する
ことを特徴とする特許請求の範囲第１項記載の洗浄方法
。 ３、カルボン酸系有機溶剤からなる液滴を洗浄薬液中に
供給することを特徴とする特許請求の範囲第１項記載の
洗浄方法。 ４、界面活性剤を洗浄薬液中に添加したことを特徴とす
る特許請求の範囲第１項乃至第３項のいずれか一に記載
の洗浄方法。 ５、硫化剤を洗浄薬液中に添加したことを特徴とする特
許請求の範囲第１項乃至第４項のいずれか一に記載の洗
浄方法。 ６、固体吸着剤を洗浄薬液中に添加したことを特徴とす
る特許請求の範囲第１項乃至第５項のいずれか一に記載
の洗浄方法。 ７、洗浄すべき半導体基板を装填した槽内に洗浄薬液を
供給するための第一の手段と、当該薬液に対して不活性
かつ不溶性の流体からなる微細な気泡又は液滴を基板近
傍の同薬液中に供給するための第二の手段と、浮上又は
沈降した気泡又は液滴を排出するための第三の手段とを
少なくとも備えたことを特徴とする洗浄装置。 ８、上記第二の手段は、アルゴンガスからなる気泡を洗
浄薬液中に供給するための手段であることを特徴とする
特許請求の範囲第７項記載の洗浄方法。 ９、上記第二の手段は、カルボン酸系有機溶剤からなる
液滴を洗浄薬液中に供給するための手段であることを特
徴とする特許請求の範囲第７項記載の洗浄方法。 １０、上記第二の手段は、洗浄槽の底部に配設した気泡
又は液滴発生用の多孔質仕切板からなることを特徴とす
る特許請求の範囲第７項乃至第９項のいずれか一に記載
の洗浄装置。 １１、上記第二の手段は、洗浄槽内部の洗浄薬液中に配
設した気泡又は液滴発生用の多孔質ノズルからなること
を特徴とする特許請求の範囲第７項乃至第９項のいずれ
か一に記載の洗浄装置。 １２、界面活性剤が洗浄薬液中に添加されていることを
特徴とする特許請求の範囲第７項乃至第１１項のいずれ
か一に記載の洗浄装置。 １３、硫化剤が洗浄薬液中に添加されていることを特徴
とする特許請求の範囲第７項乃至第１２項のいずれか一
に記載の洗浄装置。 １４、固体吸着剤が洗浄薬液中に添加されていることを
特徴とする特許請求の範囲第７項乃至第１３項のいずれ
か一に記載の洗浄装置。[Claims] 1. When cleaning a semiconductor substrate by immersing it in a chemical solution, fine bubbles or droplets made of a fluid that is substantially inert and insoluble with respect to the chemical solution are created in the chemical solution near the substrate. A cleaning method characterized by separating and discharging the metal ions in the cleaning chemical solution by supplying the cleaning chemical solution to the chemical solution and causing the bubbles or droplets to support the metal ions dissolved in the chemical solution and causing them to float or settle. 2. The cleaning method according to claim 1, characterized in that bubbles made of argon gas are supplied into the cleaning chemical solution. 3. The cleaning method according to claim 1, characterized in that droplets of a carboxylic acid-based organic solvent are supplied into the cleaning chemical solution. 4. The cleaning method according to any one of claims 1 to 3, characterized in that a surfactant is added to the cleaning chemical solution. 5. The cleaning method according to any one of claims 1 to 4, characterized in that a sulfurizing agent is added to the cleaning chemical solution. 6. The cleaning method according to any one of claims 1 to 5, characterized in that a solid adsorbent is added to the cleaning chemical solution. 7. A first means for supplying a cleaning chemical solution into a tank loaded with semiconductor substrates to be cleaned, and a means for supplying fine bubbles or droplets of a fluid that is inert and insoluble to the chemical solution near the substrate. A cleaning device comprising at least a second means for supplying into a chemical solution and a third means for discharging floated or settled air bubbles or droplets. 8. The cleaning method according to claim 7, wherein the second means is a means for supplying bubbles made of argon gas into the cleaning chemical solution. 9. The cleaning method according to claim 7, wherein the second means is a means for supplying droplets of a carboxylic acid-based organic solvent into the cleaning chemical solution. 10. Any one of claims 7 to 9, wherein the second means comprises a porous partition plate for generating air bubbles or droplets disposed at the bottom of the cleaning tank. The cleaning device described in . 11. Any one of claims 7 to 9, wherein the second means comprises a porous nozzle for generating air bubbles or droplets disposed in the cleaning chemical solution inside the cleaning tank. The cleaning device described in (1) above. 12. The cleaning device according to any one of claims 7 to 11, wherein a surfactant is added to the cleaning chemical solution. 13. The cleaning device according to any one of claims 7 to 12, characterized in that a sulfurizing agent is added to the cleaning chemical solution. 14. The cleaning device according to any one of claims 7 to 13, characterized in that a solid adsorbent is added to the cleaning chemical solution.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29712990A JPH04171724A (en) | 1990-11-05 | 1990-11-05 | Semiconductor substrate cleaning method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29712990A JPH04171724A (en) | 1990-11-05 | 1990-11-05 | Semiconductor substrate cleaning method and device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04171724A true JPH04171724A (en) | 1992-06-18 |
Family
ID=17842587
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29712990A Pending JPH04171724A (en) | 1990-11-05 | 1990-11-05 | Semiconductor substrate cleaning method and device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04171724A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6797071B2 (en) | 1998-12-09 | 2004-09-28 | Paul A. Kittle | Surface treatment of semiconductor substrates |
| JP2009522771A (en) * | 2005-12-30 | 2009-06-11 | ラム リサーチ コーポレーション | Method and apparatus for removing contamination from a substrate |
| JP2014011463A (en) * | 2012-06-29 | 2014-01-20 | Taiwan Uyemura Co Ltd | Microbubble type processing apparatus |
| WO2014013536A1 (en) * | 2012-07-17 | 2014-01-23 | 三洋電機株式会社 | Solar cell manufacturing method |
| US12046487B2 (en) | 2016-04-22 | 2024-07-23 | Kioxia Corporation | Substrate treatment apparatus and substrate treatment method |
-
1990
- 1990-11-05 JP JP29712990A patent/JPH04171724A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6797071B2 (en) | 1998-12-09 | 2004-09-28 | Paul A. Kittle | Surface treatment of semiconductor substrates |
| JP2009522771A (en) * | 2005-12-30 | 2009-06-11 | ラム リサーチ コーポレーション | Method and apparatus for removing contamination from a substrate |
| JP2014011463A (en) * | 2012-06-29 | 2014-01-20 | Taiwan Uyemura Co Ltd | Microbubble type processing apparatus |
| WO2014013536A1 (en) * | 2012-07-17 | 2014-01-23 | 三洋電機株式会社 | Solar cell manufacturing method |
| US12046487B2 (en) | 2016-04-22 | 2024-07-23 | Kioxia Corporation | Substrate treatment apparatus and substrate treatment method |
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