♦15495 經濟部中央標準局負工消费合作社印装 - B7 五、發明説明（1 ) 1 ] 本發明係有關一種絕緣溝槽（Trench Isolation)平坦 L 1 I 化（Planarization)處理之方法，利用一層預先沈積在二 *. I 氧化矽上的多晶矽（Poly-Silicon)，經化學機械研磨（ch_ 1 ^ ，1 η - emical Mechanical Polish,CMP)處理後所殘留的部份， 先1 閲 I 1 ‘ 當作漏式關（Wet Etch)之自行對準幕罩(Self_aHgne(i 背1 面 Mask) ’保護底下的二氧化矽，再利用第二次化學機械研 之 1 磨、活性離子蚀刻（Reactive I〇n Etch，RIE)、第二次濕 事1 1 1 式蝕刻，將殘留之多晶矽、氮化矽、二氧化矽研磨、蝕刻 填产Ί 寫v 掉，留下一平坦性佳之二氧化矽絕緣溝槽。 本今〉 頁1 'w 1 現今絕緣溝槽平坦化處理之方法，乃利用Gyp方法， 1 直接磨去表面二氧化矽層，得到絕緣溝槽内二氧化矽較凹 1 | 陷，而絕緣溝槽外較凸起，高低起伏大，平坦性差的表面 0 1 訂 1 參閲囷一，回填二氧化矽後絕緣溝槽之結構囷。其中 1 1 1 包含有：矽基板10、熱氧化之二氧化矽層n、氮化矽12、 1 I TE0S-Si013、小場區之絕緣溝槽15、大場區之絕緣溝槽} 6。氮化矽12爲蝕刻絕緣溝槽所用的幕軍圏案。TE〇s_Si〇 13ATE0S(Tetra-Ethyl-0rth〇-Silicate, Si(0CH))>^ 低壓化學氣相沈積法(L〇w pressure Chemical vap〇r心〜 position, LPCVD)所生成的Si〇。由於絕緣溝槽15、16階 I 梯狀高度差，使得TE0S-Si013在表面產生凹陷處17、18 • 1 f- ，凹陷程度随絕緣溝槽寬度增加而增加。寬度窜的絕緣溝 槽，其上的一氧化梦層稱爲小場區（Narr〇w Fieid 3 1 1 本紙張纽逍用巾關家料（(：刚44胁（21(^297公釐) -~~~~~_____ 1 1 1 315495 經 中 央 梂 準 扃 貝 工 合 作 杜 印 % 五、發明♦ 15495 Printed by the Consumer Labor Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs-B7 V. Description of the invention (1) 1] The present invention relates to a method for processing flat L1 I (Planarization) of insulating trenches (Trench Isolation), using Poly-silicon (Poly-Silicon) pre-deposited on the second *. I silicon oxide, after chemical mechanical polishing (ch_ 1 ^, 1 η-emical Mechanical Polish, CMP) treatment, the remaining part, first read I 1 ' Used as a self-aligning screen cover for Wet Etch (Self_aHgne (i back 1 side Mask) 'under the protection of silicon dioxide, and then used the second chemical mechanical research 1 grinding, reactive ion etching (Reactive I 〇n Etch, RIE), the second wet matter 1 1 1 type etching, the remaining polysilicon, silicon nitride, silicon dioxide grinding, etching and filling Ί write v, leaving a silicon dioxide insulation with good flatness Trench. This page> 1 'w 1 The current method of insulating trench flattening is to use the Gyp method, 1 to directly rub off the surface silicon dioxide layer, to obtain a concave silicon dioxide in the insulating trench 1 | And the insulation trench is more convex, high and low The surface with large volts and poor flatness 0 1 Set 1 Refer to Fig. 1, the structure of the insulating trench after backfilling with silicon dioxide. Among them, 1 1 1 includes: silicon substrate 10, thermally oxidized silicon dioxide layer n, nitride Silicon 12, 1 I TE0S-Si013, insulating trenches in the small field area 15, insulating trenches in the large field area 6. Silicon nitride 12 is a screen case for etching insulating trenches. TE〇s_Si〇13ATE0S (Tetra -Ethyl-0rth〇-Silicate, Si (0CH))> ^ Low pressure chemical vapor deposition method (L〇w pressure Chemical Vapor center ~ position, LPCVD) generated Si. Due to the insulating trench 15, 16 Step I The stepped height difference makes TE0S-Si013 produce depressions 17, 18 • 1 f- on the surface, and the degree of depression increases with the increase of the width of the insulation trench. The width of the insulation trench is called the dream oxide layer. It is a small field area (Narr〇w Fieid 3 1 1 paper and paper towels used to close the household materials ((: just 44 threatened (21 (^ 297 mm)-~~~~~ _____ 1 1 1 315495 approved by the central government Cooperate with Duyin and Duyin% V. Invention
的絕緣溝槽，其上的二氧化矽層稱爲大場 區（Wide Field Region)。小場區的凹陷處17，其凹陷程 度較小於由大場區的凹陷處18。二氧化矽層〗3表面的不平 坦性會降低後續製程中幕罩（Mask)囷案的精確度，比如金 屬内連線（Interconnect)製程中導線圖案精確度之降低。 因此利用CMP方法，直接磨去表面TE〇S-Si013、氮化矽12 、絕緣溝槽外熱氧化(Thermal Oxide)之二氧化梦層π。 參閲圖二，習用絕緣溝槽結構圖。經CMP處理後，得 到絕緣溝槽内一氧化碎較凹陷27、28，而絕緣溝槽外較凸 起的表面結構。雖然經CMP後，絕緣溝槽15、16内二氧化 矽的凹陷處27、28，其凹陷程度較未經CMP時的凹陷處17 、:18降低，但對後績製程中幕罩(Mask)囷案的精確度，仍 有不足。絕緣溝槽内、外的最大高低差约2〇〇毫微米。 本發明之主要目的在提供一種具多晶矽之絕緣溝槽平 坦化處理，藉預先沈積在二氧化矽上的多晶矽，經Qjp處 理後所殘留的部份，當作随後濕式蝕刻之自行對準幕軍， 保護底下的二氧化矽，再利用第二&CMP、RIE、第二次濕 式蚀刻，將殘留之多晶矽、氮化矽、二氧化矽研磨、蝕刻 掉’留下一平坦性佳之二氧化矽絕緣溝槽，消除溝槽内二 氧化矽較溝槽外凹陷的不平坦表面。 囷式之簡單説明： 圖一爲回填二氧化矽後絕緣溝槽之結構圖。 圖二爲習用絕緣溝槽結構圖。 (請先閱讀背面之注意事項再填寫本頁)The insulating trench on which the silicon dioxide layer is called the wide field region (Wide Field Region). The depression 17 in the small field area has a smaller degree of depression than the depression 18 in the large field area. Silicon dioxide layer 3 The unevenness of the surface will reduce the accuracy of the mask in subsequent processes, such as the reduction in the accuracy of the wire pattern in the interconnect process. Therefore, using the CMP method, the surface TEOS-Si013, the silicon nitride 12, and the thermal oxide (Thermal Oxide) oxide layer π outside the insulating trench are directly polished away. Refer to FIG. 2 for a diagram of a conventional insulating trench structure. After the CMP treatment, the oxide trenches in the insulating trenches have concave pits 27 and 28, and the insulating trenches have a more convex surface structure. Although after the CMP, the depressions 27 and 28 of the silicon dioxide in the insulating trenches 15 and 16 are lower than those of the depressions 17 and 18 without the CMP, but for the subsequent performance process mask (Mask) The accuracy of the case is still insufficient. The maximum height difference between the inside and outside of the insulating trench is about 200 nm. The main purpose of the present invention is to provide an insulating trench planarization process with polysilicon. By using the polysilicon deposited on the silicon dioxide in advance, the remaining part after Qjp treatment can be used as a self-alignment for subsequent wet etching The screen army protects the silicon dioxide underneath, and then uses the second & CMP, RIE, and the second wet etching to grind and etch away the remaining polysilicon, silicon nitride, and silicon dioxide, leaving a good flatness The silicon dioxide insulating trench eliminates the uneven surface of the silicon dioxide in the trench compared to the recess outside the trench. Brief description of the formula: Figure 1 is the structure diagram of the insulating trench after backfilling silicon dioxide. Figure 2 is a structure diagram of a conventional insulating trench. (Please read the notes on the back before filling this page)
本紙張从適用中困困家橾準（CNS )八4胁（210X297公釐） 315495 五、發明説明（3) 圖三爲本發明中覆蓋多晶矽後絕緣溝槽之結構圖。 囷四爲本發明中經化學機械研磨處理後絕緣溝槽之結 構囷。 圖五爲本發明中經濕式蚀刻與第二次化學機械研磨後 絕緣溝槽之結構圖。 圖六爲本發明絕緣溝槽之結構圖。 圖式中之參照數號 10矽基板 11熱氧化之二氧化矽 12氮化矽 13 TEOS-SiO 131二氧化矽表面 14多晶矽 經濟部中央標準局貝工消费合作社印裝 .(請先閱讀背面之注意事項再填寫本頁) 15小場區之絕緣溝槽 16大場區之絕緣溝槽 17小場區之二氧化矽凹陷處 18大場區之二氧化矽凹陷處 23小場區上方之二氧化矽 24 大場區上方之二氧化矽 27化學機械研磨處理後小場區之二氧化矽凹陷處 28化學機械研磨處理後大場區之二氧化矽凹陷處 34自行對準幕軍之多晶矽 37 小場區之二氧化矽 本紙張尺度適用中國國家標準（CNS ) A4规格（210 X 297公釐）This paper is suitable for use in the sleepy home (CNS) 8.4 4 (210X297 mm) 315495 V. Description of the invention (3) FIG. 3 is a structural diagram of the insulating trench covered with polysilicon in the present invention. Fig. 4 is the structure of the insulating trench after chemical mechanical polishing treatment in the present invention. Fig. 5 is a structural diagram of an insulating trench after wet etching and second chemical mechanical polishing in the present invention. FIG. 6 is a structural diagram of an insulating trench of the present invention. The reference number in the figure is 10 silicon substrate 11 thermally oxidized silicon dioxide 12 silicon nitride 13 TEOS-SiO 131 silicon dioxide surface 14 polysilicon printed by Beigong Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs. (Please read the back side first (Notes to fill out this page) 15 insulation trenches in the small field area 16 insulation trenches in the large field area 17 silicon dioxide depressions in the small field area 18 silicon oxide depressions in the large field area 23 silicon dioxide above the small field area 24 Silicon dioxide above the large field area 27 Silicon dioxide depressions in the small field area after chemical mechanical polishing 28 Silicon dioxide depressions in the large field area after chemical mechanical polishing 34 Self-aligned with the polysilicon of the screen army 37 Small field area The standard of silicon dioxide paper is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm)
38大場區之二氧化矽 茲配合囷式將本發明最佳實施例詳細説明如下。 參閲囷三，本發明中覆蓋多晶矽後絕緣溝槽之結構圖 。其中包含有：梦基板〗〇、熱氧化之二氧化矽層U、氮化 矽12、化學氣相沈積之二氧化矽層13、多晶矽層〗4、小場 區之絕緣溝槽15、大場區之絕緣溝槽16。利用化學氣相沈 積法，在回塡二氧化矽後之絕緣溝槽之上沈積一層多晶矽 14，小場區上方之二氧化矽23，其表面較小場區之二氧化 碎凹陷處17，來得平坦，而大場區上方之二氧化矽24 ,其 表面雖然也較大場區之二氧化矽凹陷處18，來得平坦，但 不平坦性仍太嚴重，不利於後績製程中幕軍圖案的精確度 ，因此先以化學機械研磨方法，將多晶矽較凸起的部份23 去除掉，留下較凹陷的部份24。 經濟部中央標準扃貝工消费合作社印製 (請先閲讀背面之注意事項再填寫本頁) 訂 參閲囷四，本發明中經化學機械研磨處理後絕緣溝槽 之結構囷。以CMP方法除去多晶矽層時，因絕緣溝槽外之 多晶矽較凸起，會先被磨去，而在大場區上方的多晶矽34 ，則因較凹陷而殘留下來。以殘留下來的多晶矽34，當作 随後濕式蝕刻的自我對準幕軍，保護底下的二氧化矽免被 蚀去，而裸露的二氧化矽則利用含氫氟酸(HF)的溶液進行 杜刻，接著再以第二CMP方法除去該殘留的多晶矽層34。 參閲圖五，本發明中經濕式蝕刻與第二次化學機械研 磨後絕緣溝槽之結構圖。經第二CMP去除多晶矽層後，並 進一步回蝕（Etch-Back)底下部份的的二氧化矽，形成平 . _____ 6_ _ 本紙張尺度適用中國國家標準（CNS )八4規格 (210X297公釐） 315495 at ------ B7 五、發明説明（5 ') ---- 坦性佳的二氧化碎層表面131，利用活性離子蚀刻法(RIE) 回蚀氮化带12上方的二氧切層13，接著以經加熱的含鱗 酸(Phosphoric Acid, HPO)溶液，蝕刻氮化矽12 ,最後 再以含氫氟酸(HF)的錢將崎溝槽外的二氧财蚀刻掉 Ο 參閲囷六，本發明絕緣溝槽結構圖。其中包含有：矽 基板10、熱氧化之二氧化矽層n、小場區之二氧化矽37、 大場區之二氧化矽38。經濕式蚀刻法，蝕刻絕緣溝槽外的 二氧化矽後，絕緣溝槽内、外的最大高低差約4〇毫米，比 習用200毫微米的最大高低差，約降低75%，解決絕緣溝槽 内二氧化矽較凹陷的不平坦問題。 综上所述，當知本案發明具有實用性與創作性，且本 發明未見之於任何刊物，當符合專利法規定。 唯以上所述者，僅爲本發明之一較佳實施例而已，當 不能以之限定本發明實施之範圍。即大凡依本發明申請專 利範圍所作之均等變化與修飾，皆應屬本發明專利涵蓋之 範圍内。 (請先閲讀背面之注意Ϋ項再填寫本頁)The 38-field silicon dioxide and the compound formula describe the preferred embodiment of the present invention in detail as follows. Refer to Fig. 3, the structure diagram of the insulating trench covered with polysilicon in the present invention. It includes: dream substrate〗 〇, thermally oxidized silicon dioxide layer U, silicon nitride 12, chemical vapor deposited silicon dioxide layer 13, polysilicon layer〗 4. Insulation trenches in small field area 15, large field area The insulating trench 16. Using chemical vapor deposition, deposit a layer of polysilicon 14 on the insulating trench after the silicon dioxide, silicon dioxide 23 above the small field area, and a small area of the silicon dioxide crushing depression 17 on the surface The surface of the silicon dioxide 24 above the large field area is flat, although the surface of the silicon dioxide depression 18 of the large field area is flat, but the unevenness is still too serious, which is not conducive to the accuracy of the screen pattern in the subsequent performance process. Therefore, first remove the more convex part 23 of the polysilicon by chemical mechanical polishing method, leaving the more concave part 24. Printed by the Central Standard of the Ministry of Economic Affairs, Pui Pongong Consumer Cooperative (please read the precautions on the back before filling in this page). Order Refer to Fig. 4. In this invention, the structure of the insulating trench after chemical mechanical polishing treatment. When the polysilicon layer is removed by CMP, the polysilicon outside the insulating trench is more protruding and will be removed first, while the polysilicon 34 above the large field area remains due to the depression. The remaining polysilicon 34 is used as a self-alignment screen for subsequent wet etching to protect the underlying silicon dioxide from being etched away, while the exposed silicon dioxide is carried out using a solution containing hydrofluoric acid (HF) Then, the remaining polysilicon layer 34 is removed by a second CMP method. Referring to FIG. 5, the structure diagram of the insulating trench after wet etching and the second chemical mechanical grinding in the present invention. After the second CMP removes the polysilicon layer, and further etch back (Etch-Back) the silicon dioxide underneath to form a flat. _____ 6_ _ This paper scale is applicable to China National Standard (CNS) 84 specifications (210X297 mm ) 315495 at ------ B7 V. Description of the invention (5 ') ---- The fragile surface of the finely oxidized dioxide layer 131, using reactive ion etching (RIE) to etch back the two above the nitrided strip 12 Oxygen-cutting layer 13, then etched silicon nitride 12 with heated Phosphoric Acid (HPO) solution, and finally etched the dioxins outside of the trench with hydrofluoric acid (HF) money Ο Refer to Fig. 6, the structure diagram of the insulating trench of the present invention. These include: silicon substrate 10, thermally oxidized silicon dioxide layer n, silicon dioxide 37 in the small field area, and silicon dioxide 38 in the large field area. After etching the silicon dioxide outside the insulation trench by wet etching, the maximum height difference between the inside and outside of the insulation trench is about 40 mm, which is about 75% lower than the maximum height difference of the conventional 200 nm. The unevenness of silicon dioxide in the groove is more concave. In summary, when the invention of this case is known to have practicality and creativity, and the invention is not seen in any publication, it should comply with the provisions of the Patent Law. The above is only one of the preferred embodiments of the present invention, and it should not be used to limit the scope of the present invention. That is to say, any changes and modifications made in accordance with the scope of the patent application of the present invention shall fall within the scope of the patent of the present invention. (Please read the note Ϋ on the back before filling this page)
A 訂A set
J 經濟部中央梂準局員工消费合作衽印製 Μ 縣J Printed by the Ministry of Economic Affairs, Central Bureau of Economic Cooperation and Employee Consumption Cooperation M County
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