TW552671B - Formation method of shallow trench isolation structure with Si/SiGe substrate - Google Patents

Abstract

This invention provides a formation method of shallow trench isolation (STI) region with Si/SiGe substrate, which comprises the following steps: providing a semiconductor substrate; depositing a Si/Ge layer on the semiconductor substrate; forming a Si layer on the Si/Ge layer to form the above-mentioned Si/SiGe layer substrate; providing a patterned hard mask layer on the Si/SiGe layer substrate to define the STI region of the Si/SiGe layer substrate; using the hard mask pattern as a mask to etch the Si/SiGe layer substrate to form a plurality of trenches, in which (I) oxygen mixed with (II) hydrogen bromide, chlorine or their combination are used as the etching source for plasma etching; forming a liner layer on the side wall of the trenches; depositing a dielectric layer to fully fill the trenches; performing a planarization process to remove the dielectric layer outside of the trenches to complete the STI region with Si/SiGe substrate.

Description

552671 V. Description of the invention (1) The present invention relates to a method for forming a shallow trench isolation structure with a stone / silicon-germanium layer substrate, and particularly relates to forming silicon on a pseudo substrate formed by a silicon-germanium layer. Layer, and a manufacturing method of forming a shallow trench isolation structure on the silicon / silicon germanium substrate. Isolation semiconductor elements (semiconductor Qr elements isolation) such as transistors, etc., can generally be achieved by local silicon oxidation (LOCOS) or shallow trench isolation structure (sn: shall isolation) where the shallow trench isolation structure is usually formed In the two active sections, the trench is filled with an isolation substance. The use of shallow trench isolation technology can avoid the problems of topographical irreguurities caused by local silicon oxide (LoCos) isolation, and the intrusion of oxide layers due to the use of a silicon nitride layer as a mask (Encr0achment) bird's beak effect in the active area. Therefore, in addition to using shallow trench isolation structure, in addition to having a relatively high package density, there is still greater planarity and good Isolation quality and other advantages. Traditionally, a trench-isolated structure (as disclosed in U.S. Patent Nos. 6 1 & 2 8 5 & and 6 1 10 7 9) is a shallow trench isolation structure formed by etching a silicon substrate. However, with the reduction in the size of the gate element, it is quite difficult to make the gold oxygen field-effect transistor (MOSFET) element with high actuating current and high speed under low operating voltage. Therefore, many people are trying to find a way to improve the performance of metal-oxide half-field-effect transistor devices. Strain-induced band structure modification is used to increase the mobility of carriers to increase the actuating current of the field effect transistor, which can improve the performance of the field effect transistor element, and this method has been applied to various elements. When Shi Xi M0SFET Yuan

552671 V. Description of the invention (2) :: When the channel is under tensile strain, electrons can be increased and: ^ dtJ: II. The present invention provides a method for forming shallow trenches. The layer is larger, Λ trench isolation structure; due to germanium (which is a large metal of silicon, it is doped in silicon. It is a kind of original: the germanium layer is thin m, which makes the remote crystal = The method for forming shallow trenches according to the present invention is relatively loose, at least while extending. Bottom; Shen ... Is the wrong layer on the semiconductor substrate: Provided by: Hardness to form the above-mentioned Shixi "XiGe layer substrate; : More: The curtain layer is on the silicon / silicon-germanium layer substrate to define the second trench isolation region in the aforementioned pattern ^; the last name is Xishi / Shixi Bilayer Substrate-Layer 2 with (Work-Mixed (Π) Desert The source of hydrogen gas, the gas channel, and the plasma are etched; a gasket layer is formed on the sidewall of the trench: u2 is a face-centered dielectric layer to fill the trenches; The dielectric layer outside the trenches, such as 5H, is removed to complete the two shallow trench isolation regions. // The effect of the invention of the shield substrate is to provide a Adding electronic and electrical trench isolation structure, and can control the depth and thickness of the shallow trench etched. Example of Fu Zeliang: Please refer to Figures 1 to 6 to explain the manufacturing process of the embodiment of the present invention. FIG. 1 provides a semiconductor substrate such as a silicon substrate or a substrate with silicon on an insulating layer. On this substrate, a chemical &

552671 V. Description of the invention (3) Epitaxy method of vapor deposition (CVD), for example, a gas containing Shi Xi and germanium atoms (for example, SiH4, GeH ^ l is appropriately mixed into the substrate 100) In the cavity, a relatively rolled body is formed, such as Si ", layer ". The ratio of ytterbium to germanium can be y: erroneous (for example, the rate of migration should be adjusted appropriately; then, the same,: Move the gas of Shixi, grow a layer of Shixi layer 120 in the broken germanium layer. ^: Method 'access only Shixi fault thickness range is 50 ~ 300mm and 4000: layer, and then Review the second figure, and then form a 0A with a pattern. It is used as a cover for subsequent etching steps. Among them, the hard mask layer 130 Γ: ΓΓΛ5: 0A 5 The hard mask layer 13G is preferably composed of From bottom to top, it is sequentially cut by oxygen. And the milk is composed of fossil evening // localization or oxygen cutting / nitrogen cutting / nitrogen oxygen cutting, ΐΐ =: dioxin r Q +,.... Conventional c) or low-repeated chemical vapor deposition (: r =: "position; lpcvd) is used to deposit ^ ^ ^ layers can be used low-pressure chemical vapor deposition ^, to plant chlorosilane (s 1 c 丨2%) Ammonia gas (νη3) is used as a reaction raw material, and a photoresist mask is used to cover the subsequent active elements, I, 1 nitride layer and oxide layer, and dry etching is performed to expose the subsequent shallow trench isolation. After the J, please refer to FIG. 3, following the outline left after the hard mask layer 13 is etched, the silicon layer 120 and the silicon germanium layer are etched to a predetermined depth to form a shallow trench. 140 ° Wherein the LX layer 120 and the ShiXi germanium layer 11G can be used. Page 6 0503-8059TWF; TSMC2001-1670; Rita.ptd 552671 V. Description of the invention (4) " 一 " _ formed by a variety of milk bodies In the rest of the time, the source is anisotropic #, f method of low, medium or high density plasma to remove it; and the above-mentioned etching source to be mixed must not only contain oxygen, but also chlorine, bromine Hydrogen hydride or at least one of them, and at the same time: selectively mixing nitrogen fluoride (comment 3), isthmus gas (Cx Fx) and other gases into the mixed gas to increase the etching rate or effectively control # 刻 之》 朱Degree and profile, you can also add helium, argon or nitrogen as the carrier gas. In order to use high-density plasma etching, the etching source gas is mixed according to the following table: Parameter flow ratio flow rate (seem) power (W) pressure 〇Torr) monitoring degree (V) gas type \ ^ HBr: Cli: 〇2 150: 30: 40 150: 30: 4 200-1500 5-150 20-80 HBr: 02 30 ~ 1〇30: 1-10: 1 200-1500 5-150 20 ~ 80 Ch: 〇2 20-5 20 : 1-5: 1 200-1500 5-150 20 ~ 80 I Insect fragmented layer 1 2 0 and Shixi staggered layer 丨 丨 〇 After the predetermined depth is completed, a shallow trench 140 is formed, and the depth range can be about 2500 ~ 5000 people. After the completion of the shallow trench 1 4 0, as shown in FIG. 4, a lining layer 150 is formed on the inner wall of the trench 140. The lining layer 1 50 can be subjected to a thermal oxidation process using A thin thermal oxide layer is grown on the sidewall of the trench 140, and its thickness is about 180 A. Next, as shown in FIG. 5, the dielectric layer is filled in the trench 160. For example, 03 and TEOS can be used as reactants, and an atmospheric pressure chemical vapor deposition (APCVD) process can be performed, or Silicon oxide deposited by density plasma

0503-8059TWF; TSMC2001-1670; Rita.ptd Page 7 552671 V. Description of the invention (5) — (HDP-SiOd, an oxide layer 16 is formed to fill the shallow trench 140 and cover the hard cover curtain layer On the surface, a device isolation region as shown in the figure is obtained, and it has good trench filling properties. Finally, as shown in FIG. 6, a planarization process such as chemical mechanical polishing (CMP) is performed. ) Or etch back process, remove the excess dielectric layer outside the trench 1 40, 60, and complete this shallow trench isolation region process. The method of forming shallow trenches, which is inherently bright, uses germanium in stone. A silicon layer is formed on a pseudo substrate formed by the layers, and a shallow trench structure is formed on the silicon / silicon-germanium substrate, which can increase electron and hole mobility, and the etching formula and plasma etching method of the present invention can be used. The depth and pattern of the etched shallow trenches are well controlled. Although the present invention is disclosed above in the preferred embodiment, it is not intended to limit the invention of the scholar. Anyone skilled in this art will not depart from the spirit and guilty of the present invention. Inside, when you can make a few changes and retouching, so Subject to the scope of the attached patent application.

552671 Brief description of the drawings In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments and the accompanying drawings in detail, as follows: FIG. 6 It is a schematic cross-sectional view of a manufacturing process according to an embodiment of the present invention. Explanation of symbols: 100 ~ substrate; 1 10 ~ sand germanium layer; 120 ~ silicon layer; 130 ~ hard cover curtain layer; 140 ~ trench; 150 ~ general layer; 1 60 ~ dielectric layer .

0503-8059TWF; TSMC2001-1670; Rita.ptd page 9

Claims (1)

552671 6. Scope of patent application 1. A silicon / silicon-germanium substrate includes the following steps. A trench isolation region forming method (a) provides a silicon-germanium reed in order to form the aforementioned silicon / silicon-germanium substrate; 9 The semiconductor substrate of the layer is provided with (b) a patterned = hard mask to define the silicon / silicon-germanium layer A% ^ ... silicon / silicon-germanium layer substrate, N increases the shallow trench isolation area of the substrate; It is thought that (c) the silicon / silicon germanium layer substrate is etched to form a mixed gas (Π) hydrogen bromide gas, chlorine gas or etched with (1) ^ slurry. The upper mouth is an etching source. The method of forming a silicon / silicon germanium reed tank isolation area as described in item 丨 of the patent application scope is performed, further including the following steps: soil-, under / (d) in the trench A liner layer is formed on the sidewall; (e) a dielectric layer is deposited to fill the trench; and (f) a planarization process is performed to remove the dielectric layer outside the trenches to complete a silicon / silicon A shallow trench isolation region on a germanium layer substrate. 3. The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item 2 of the patent application scope, wherein the planarization process is a chemical mechanical polishing (CMP) process or an etch back process. 4. The method for forming a shallow trench isolation region of a silicon / silicon-germanium substrate as described in item 1 of the patent application scope, wherein the semiconductor substrate is a silicon substrate or a substrate with silicon on an insulating layer. 5. The method for forming a shallow trench isolation region of a shixi / shixi germanium layer substrate as described in item 1 of the scope of patent application, wherein the silicon germanium layer is epitaxy by chemical vapor deposition (CVD) 'Will mix containing silicon and germanium atoms 0503-8059TWF; TSMC2001-1670; Rita.ptd 552671 VI Scope of patent application _ ^ Gas, the semiconductor substrate is placed. Silicon germanium is deposited to form a semiconductor layer 6 in accordance with the method of claim 5, the trench isolation region forming method, and a shallow trench SlH4 or GeH4 on the substrate of the germanium / shixi germanium layer. The gas used for chemical vapor deposition includes the method for forming a trench isolation region as described in item 1 of the scope of the patent application. The thickness of the shallow trench of the 1 ar layer is 8 ^ The thickness of the silicon layer ranges from 50 to 300 A. . Slot P 的 The shallow trench in the silicon / silicon-germanium substrate described in the previous item. The silicon germanium layer has a target range of 4000 to 20000. 9. The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item 丨 of the patent application scope, wherein the hard mask layer includes silicon oxide and nitrogen. Chemical hair, silicon oxynitride, or a combination thereof. 10. The method for forming a shallow trench isolation region of a silicon / silicon-germanium layer substrate as described in item 1 of the scope of the patent application, wherein the step (C) is to etch the stone Xi / Shi Xi with a low, medium or high density plasma. Split level. 11. The method for forming a shallow trench isolation region of a silicon / silicon-germanium layer substrate as described in item 丨 0 of the scope of the patent application, wherein the gas flow ratio of the etching source is c 12: 02 2 0 5. 1 2. The method for forming a shallow trench isolation region of a shixi / shixi germanium layer substrate as described in Item 10 of the scope of patent application, wherein the gas flow ratio of the etching source is HBr: 02 to 30 ~ 10. 1 3 · The method of forming a shallow trench isolation region of a split-layer substrate as described in item 10 of the scope of patent application, wherein the gas flow ratio of the etching source is c ": 0503-8059TWF; TSMC2001-1670; Rita.ptd Page 11 552671 /, Patent application scope HBr: 02 2 15 0: 3 0:40. 14 · The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item No. 丨 0, wherein the power range of the etching is in the range of 2 0 ~ 1 5 0 0 W, 1 5 The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate according to the range of item 10, wherein a temperature range during etching is 20 to 80 ° C. 1, 16 · The method for forming a shallow trench isolation region of a silicon / silicon-germanium substrate as described in item 10 of the scope of patent application, wherein the pressure range during etching is 5 to 150 mTorr 〇, 13 · As the scope of patent application No. 1 The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate according to the item, wherein the process of etching the silicon / silicon germanium layer substrate further includes an atmosphere, argon, nitrogen, nitrogen fluoride (NF3), carbon Fluoride gas (CxFx) or a mixture thereof. ,, # As described in the patent application for item 1 of the silicon / silicon germanium substrate. A method for forming an isolation region, wherein the depth of the trench is in the range of 2500 to 50 0 0 ^ α 丨 9. A method for forming a shallow trench isolation region with a silicon / silicon germanium layer substrate includes the following steps: (a) Provide a substrate with silicon on the insulating layer; (b) sequentially form a silicon germanium layer and a silicon layer with a silicon substrate on the insulating layer to form the aforementioned silicon / silicon germanium substrate;-provide a patterned substrate The hard mask layer is on the silicon / silicon-germanium substrate, and the trench is a shallow trench isolation region of the silicon / silicon-germanium substrate. The hard mask is on page 12 0503-8059TWF; TSMC2001-1670; Rita.ptd 552671 Sixth, the scope of patent application --- the layer contains silicon oxide, silicon nitride, silicon oxynitride, or a combination thereof; (d) I engraved the Shi Xi / Shi Xi interlayer substrate to form a trench. The etching gas used to etch the silicon / silicon germanium layer substrate includes: (I) oxygen; or a group thereof (Π) hydrogen bromide, chlorine gas, or a combination thereof; and (m) nitrogen fluoride (nfs), a fluorocarbon gas (c F (e) forming a liner layer on the sidewall of the trench; (f) depositing a dielectric layer to fill the trench; and (g) performing a flat In the manufacturing process, the dielectric layer of the outer layer of Qiu + Ren + a I leaves is removed, and a shallow trench isolation region with a Shixi / Shixi germanium substrate is formed. 20. As described in item 19 of the scope of patent application Method for forming a shallow trench isolation region on a silicon / silicon layer, wherein the silicon germanium layer is introduced by a chemical epitaxial deposition / (CVD) epitaxy method, and a gas containing a stone and a stray atom is introduced into the silicon germanium layer. A silicon germanium layer is deposited in the cavity in which the semiconductor substrate is placed. 2 1 · A method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item 20 of the patent application scope, in which a chemical gas is used The phase-deposited gas includes SiH4 or GeH4. 2 2 · The method for forming a shallow trench isolation region of a silicon / silicon-germanium substrate as described in item 19 of the patent application scope, wherein the thickness of the silicon layer ranges from 50 to 30 0 A. 2 3 · The method for forming a shallow trench isolation region of a silicon / silicon-germanium layer substrate as described in item 19 of the scope of patent application, wherein the thickness of the silicon-germanium layer ranges from 4 0 0 to 20000 A 〇 0503-8059TWF; TSMC2001-1670; Rita.ptd Page 13 552671 VI. Patent application scope, 24. Method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item 19 of the patent application scope, wherein The gas for etching the silicon / silicon-germanium substrate further comprises helium, argon, or at least one of them. 2. 25. The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item 19 of the scope of the patent application, wherein the planarization process is a chemical mechanical polishing (CMP) or etch back process Alas. 26. The method for forming a shallow trench isolation region of a silicon / silicon germanium layer substrate as described in item 19 of the scope of the patent application, wherein the trench depth ranges from 2 500 to 5 0 0 A 〇, 2 7 The method for forming a shallow trench isolation region of a silicon / silicon-germanium layer substrate as described in item 19 of the patent application scope, wherein (d) the silicon / silicon-germanium layer is etched with low, medium, or high-density electropolymerization . 28. The method for forming a shallow trench isolation region of a shixi / silicon-germanium substrate as described in item 27 of the scope of the patent application, wherein the gas flow ratio of the etching source is Cl2: 〇2 220 ~ 5. 2 9. The method for forming a shallow trench isolation region of a shixi / silicon-germanium substrate as described in item 27 of the scope of patent application, wherein the gas flow ratio of the etching source is HBr: 〇2 230 ~ 1 〇〇30 · According to the method for forming a shallow trench isolation region of a shixi / silicon-germanium substrate as described in item 27 of the scope of the patent application, wherein the gas flow ratio of the etching source is Cl2: HBr: 02 = 150: 30: 4. 31. The method for forming a shallow trench isolation region of a shixi / silicon-germanium substrate as described in item 27 of the scope of patent application, wherein the power range of the etching is in the range of 2000-1500W. 0503-8059TWF; TSMC2001-1670; Rita.ptd Page 14 552671 VI. Patent application scope 32. A method for forming a shallow separation region of a silicon / silicon-germanium layer substrate as described in item 27 of the patent application scope, wherein during etching The temperature range is from 20 to 80 ° C. 4_3ρ3 · μ The method for forming a shallow trench barrier region of a silicon / silicon-germanium layer substrate as described in item 27 of the patent application scope, wherein the pressure during etching ranges from 5 to 150 mT0rr. Sentence, deaf-like 3p4 · 龅 As described in ΛPlease / Professional scope of item 19, the shallow trench of the Shixi / Shixi germanium layer substrate is said to form the Pwj away zone, and the rh / gas is more enclosed in the gas, which is etched The manufacturing process of the germanium layer substrate further includes milk, nitrogen, helium, or a combination thereof. Page 15