TW563186B - Surface treatment method of low dielectric constant material - Google Patents

Abstract

This invention discloses a surface treatment method of low dielectric constant material, which comprises the following steps: depositing a low dielectric constant material on the surface of a semiconductor substrate to form a dielectric layer and performing a hydrogen plasma treatment process to reduce the dielectric constant of the dielectric layer.

Description

563186 V. Description of invention 〇) Invention collar! Xijiming is related to semiconductor process technology, and in particular, to good and reliable production. The method ′ can increase the breakdown voltage while reducing the dielectric constant. Technology back; integrated circuits are becoming more sophisticated and complicated = enough metal interconnects are made on the surface, most of them are currently; 5 :: = layered (: structured to complete the connection of various components; = belong to Eight metal interconnects = ter-MetaiDielectrics) as a material package for isolating the electrical layers. It is used in the art as an intermetallic intermediary. Plasma ^ anCed 〇Xlde ), Plasma tetraethoxy silicate glass (PE-TE0S; S: two-hanced tetraethyl orthosilicate glass), a number of dielectric materials (such as the Dow-coring company produced p, over the years, in order to match the size of the components The need for development and improvement of component = speed '. Copper genus with low resistance constant and high electron migration resistance has gradually been used as the material of metal interconnects, replacing the previous aluminum metal process technology. Among them, copper metal inlay Cu (Damascene) interconnect technology can not only reduce the size of interconnects, but also solve the problem of difficult copper metal etching, so it has become the main development trend of multiple interconnects today. On the other hand, Dielectric layer The electrical energy can be reduced as much as possible. At present, such as fluorine doped oxide layer (F SQ), hydrogen doped oxide layer (HSQ, hydrogen silses_quioxane), methyl group 563186 5. Invention description (2) Doped oxidation Layer (MSQ; methyl si lsesquioxane) and other low dielectric constant materials as the intermetal dielectric layer to reduce cross talk (cross talk) and RC time delay. "Generally known low on the substrate or semiconductor components On top of the dielectric layer of the dielectric constant material, a plasma treatment process of ammonia gas (NH3) will be used to remove copper oxide (Cu0) that may be generated in subsequent steps. However, this treatment will also expose the low dielectric constant material to ammonia. The damage of gas plasma is even worse. The problem of damage caused by the above-mentioned ammonia gas plasma surface is worse than the above. The invention is summarized here. The surface treatment of this material The effect of the program, the reliability of the breakdown voltage product of the interlayer dielectric layer (rel iabi dependent dielectr constant material, the dielectric layer of the dielectric layer, in order to achieve the above purpose, surface processing method, the step of a semiconductor substrate shape processing program. High Density Plasma Chemical Vapor Phase Another type of processing procedure of the present invention makes an effective improvement of the dielectric layer surface of low dielectric constant materials urgent. The main purpose of Ming is to provide a low dielectric constant method. The conventional ammonia gas is used to remove copper oxide, reduce impurities and improve metal (breakdown voltage), so shorten the time-dependent dielectric breakdown (ic breakdown) related to 1 1 ty), and also have the advantage of lowering the electrical constant . The present invention provides a table of a low dielectric constant material. It should include: depositing a low dielectric constant material and a second dielectric layer; and performing an electric feeding of hydrogen. The processing procedure is performed by electropolymer chemical vapor deposition = 'deposition method. , Or state-surface treatment of a low dielectric constant material

563186 Description of the five inventions (3) _______ — method, which is characterized by increasing the breakdown voltage to obtain a plasma treatment program to remove copper oxide. Step: deposit a low dielectric constant Product, the process includes the following step layer; defines an opening in the dielectric = forms a dielectric on the semiconductor substrate and fills the opening; w is medium; deposits a copper metal layer on the copper metal outside the dielectric layer Layer; and a plasma treatment process for removing hydrogen from the surface of the dielectric layer or the copper metal layer by mechanical grinding to remove the openings. < Lice copper and reduce the dielectric constant of the dielectric layer

This example is based on the Tailuo Japanese daily interconnection process, and the mosaic structure ... Those who are familiar with this technique can also apply it to the dual mosaic process. <-Please refer to FIG. U, which shows the initial steps of this embodiment. The part numbered 0 is a semiconductor element that may include several layers of metal interconnects and several electrical phases, such as M0S transistors, resistors, logic elements, etc. In order to simplify the diagram, the intermetallic Semiconductor substrates and integrated circuit elements below the electrical layer 102 are represented by the reference numeral 100 only.

The dielectric layer 102 represents a low-dielectric-layer-constant dielectric material, usually a carbon-doped or hydrogen-doped silicon oxide (S i OC: Η) -type dielectric material, such as a hydrogen-doped oxide layer (HSQ; hydrogen sil ses). -qu i oxane), methyl-based 4-doped oxide layer (MSQ; methyl silsesquioxane), hydrogen-doped poly oxide layer (H-PSSQ; hydrio polysilsesqu io xane), methyl-doped poly oxide layer (M-PSSQ; methyl polysilsesquioxane), phenyl polysilsesquioxane (P-PSSQ), fluorine-doped

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563186 V. Description of the invention (4) Parylene (FLARE; Allied Signal or Microwave

(Manufactured by Materials), aromatic hydrocarbons (manufactured by Siu; manufactured by Dqw Chemical), xerogei, nanoglass, polyarylene ether-2 (PAE-2), and the like. The dielectric constant of the above materials is generally around 3, but the range can be between 1-4. This dielectric layer can be deposited by chemical vapor deposition (CVD) or spin coating in 9 ways on a substrate, and then cured to form a dielectric film as shown in the figure. Please refer to FIG. 1B. Then, according to the traditional mosaic process, first use the lithography and #lithography procedures to define the dielectric interconnects in the dielectric layer 1 102. Please refer to Figure 1C, define the metal interconnect trenches again by lithography and etching procedures, and then perform a comprehensive deposition to form a metal resistance between the interconnect trenches and the bottom and sidewalls of the via window. Barrier layer 丨 〇4. This barrier layer 〇4 can help the subsequent metal adhesion and prevent its diffusion. For copper, suitable diffusion barrier layer materials include: button (Ta), nitride button (TaN), hafnium nitride (WN) 'Or titanium nitride (T i N) commonly used in conventional processes.

Please refer to FIG. 1D. Next, a steel metal layer 1 is deposited on the barrier layer 104 by chemical vapor deposition (CVD), physical vapor deposition (PVD), or electroplating (Eiectrplating). 0 6 and make it fill the aforementioned interconnecting trenches and vias. Preferably, an ionized metal plasma (I MP) can be used to first deposit a seed layer having a thickness of about 3,000 to 15,000 angstroms, and then the copper conductive layer can be deposited by an electrical bonding method. Usually, the deposition process of the barrier layer and the seed layer can be completed sequentially in different chambers of the multi-chamber reaction chamber.

0503-8135B / f; TSMC2002-0261; Chiumeow.ptd 563186 V. Description of the invention (5) It can be completed without breaking the vacuum to improve the reliability and productivity of the process. Next, "please refer to Fig. 1E, after the barrier layer 104 and the copper metal layer 106 have been deposited," planarize by chemical mechanical polishing method, and then copper metal layer 106 and the copper metal layer other than the interconnect trenches. The barrier layer 104 is removed, and the grinding process includes: grinding of copper metal, grinding of the barrier layer, and a final oxide buff ing procedure, wherein different stages use different grinding liquids. According to the invention, a hydrogen plasma treatment process is performed on the surface of the dielectric layer 10 with a low dielectric constant after chemical mechanical polishing. The processing conditions of the above plasma treatment process are as follows: the processing time is between 40 seconds 10 seconds is preferred; processing temperature is between 20 ~ 500 ° C, preferably 400 ° C; gas flow rate during processing is between 100 ~ 200 sccm, and 66 ° sccm is The processing pressure is between 1T ~ 7T, preferably 4T; the operating power is between 50 ~ 300W, preferably 600W. In addition, the above-mentioned plasma treatment process is performed by a plasma chemical vapor deposition method or a high-density plasma chemical vapor deposition method. After that, the nitrided layer 108 is covered again to obtain the structure shown in FIG. The hydrogen plasma treatment process of the method of the present invention has the following advantages: 1) the hydrogen plasma treatment process has a reduction ability better than the ammonia plasma treatment process, which can reduce copper oxide to obtain relatively pure copper, 2) The reduction of the copper oxide of the dielectric layer and the copper wire can increase the breakdown voltage at the same time, thereby shortening the Unie-dependent dielectric breakdwn related to product reliability (rel iabi 丨 i ty). Better reliability, 3) Although the surface treatment of the dielectric layer will not react with the surface, it is only & original copper oxide, and it has good adhesion to the surface of the dielectric layer of low dielectric constant materials.

563186 V. Description of the invention (6) -------- Help ‘at the same time’ 4) The above-mentioned low dielectric constant materials and electric constants. The dielectric layer can also reduce the exposure as above, but it is not used without departing from the decoration of the present invention ', so the warranty of the present invention shall prevail. Although the present invention has been limited to the present invention by a preferred embodiment, anyone skilled in the art can, within the scope of ::, make various changes and modifications. The scope of patents attached to the scope of the application is bounded by 563186 Brief description of the drawings In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail with the accompanying drawings as follows: Section 1 A ~ 1 Figure F is a series of cross-sectional views illustrating a mosaic copper process according to a preferred embodiment of the present invention. Explanation of symbols: 100 ~ substrate and semiconductor element; 102 ~ low intermetal dielectric layer; 10 ~ 3 plasma processing program; 104 ~ barrier layer; 106 ~ copper metal layer; 10 8 ~ top cover.

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Claims (1)

563186 VI. Application scope of patent 1 ·-Low dielectric constant material ^^-m · The surface treatment method of the rod, including the following steps / especially low " electrical material material " in a semiconductor mesoelectric layer; and A dielectric constant is formed on the bottom layer to perform a hydrogen layer on the dielectric layer. Water treatment program to reduce the dielectric 2 · If the scope of patent application is the first! The surface treatment method described above, wherein the low dielectric constant is low: the surface of the dielectric constant material or the spin coating method is deposited on the substrate. Based on chemical vapor deposition method 3 · The surface treatment method as described in item 1 of the scope of patent application, wherein the plasma treatment of the seed dielectric constant material table method or high-density plasma chemical vapor deposition = applying 7 to electricity Slurry chemical vapor deposition 4. As described in item 1 of the scope of patent application & An eight-sided treatment method, in which the plasma treatment process is performed; the table of electrical constant materials is between seconds. The processing time of the king is between 10 ~ 40 5 · As described in Item 8 of the patent application scope, the surface treatment method, wherein the plasma processing program has a dielectric constant material table of ° C, and the processing pressure is between 1T ~ 7T. The processing temperature is between 2 ～ 5〇06. As described in item 1 of the scope of patent application, the surface treatment method, wherein the plasma treatment program% dielectric constant material is shown in the table 2 0 0 0 sccm. The gas flow rate is between 100 ~ L, such as the surface treatment method described in item 丨 of the patent scope, wherein the plasma treatment process is dielectric. The constant material is between 3 0 0 W. I of Known as power between 5 0 563186 A method for surface treatment of a variety of low dielectric constant materials, including the following steps: layer deposition-low dielectric constant material on a semiconductor substrate to form a dielectric, an opening in the dielectric layer, "You 3 a copper metal layer on the dielectric layer and filling the opening; removing copper and gold outside the opening by chemical mechanical polishing and applying a hydrogen I [之 雷 将 + m ^^ 'and the surface of the layer: Jr process To remove the emulsified copper of the dielectric layer and the copper metal, and reduce the dielectric constant of the dielectric layer. 9. The low dielectric constant material as described in item 8 of the scope of the patent application. The dielectric constant material is deposited on the substrate in a chemical vapor deposition method. I. The table of low dielectric constant materials as described in item 8 of the scope of the patent application: the physics method, the plasma treatment program in # is a plasma chemical vapor deposition method or a southern density plasma chemical vapor deposition method. Law enforcement. II. The surface treatment method of the low dielectric constant material as described in item 8 of the scope of the patent application, wherein the processing time of the plasma processing sequence is between 丨 and 40 seconds. 1 2 · The surface treatment method for the low-dielectric constant material as described in item 8 of the scope of the patent application, wherein the treatment temperature of the plasma treatment program is between 20 ~ 500 ° C, and the treatment pressure is between 1 τ ~ 7 τ. 1 3. The surface treatment method for a low-dielectric constant material as described in item 8 of the scope of the patent application, wherein the gas flow rate of the plasma treatment process is between 丨 00 and 2000 sccm. 563186 6. Scope of patent application 1 4 · Surface treatment method of low dielectric constant material as described in item 8 of the scope of patent application, wherein the operating power of the plasma processing program is between 50 ~ 300W. 15 · The surface treatment method for the low-dielectric constant material according to item 8 of the scope of the patent application, wherein before depositing the copper metal layer, further comprising: depositing a barrier layer on the bottom and sidewall of the opening. 16 · The surface treatment method for the low-dielectric constant material as described in item 15 of the scope of patent application, wherein the material of the barrier layer is selected from the group consisting of: titanium nitride (TiN), tantalum ( Ta), nitride button (TaN), and tungsten nitride (WN). 0503-8135TWf; TSMC2002-0261; Chiumeow.ptd page 13