Compositions, uses and methods for selectively etching silicon-germanium materials - Patents.com

Abstract

The present invention relates to a composition for selectively etching a first silicon germanium layer having a first germanium content in the presence of a silicon layer or a second silicon germanium layer having a second germanium content, wherein the first germanium content is higher than the second germanium content, the composition comprising: (a) 0.1 to 10 mass % of an oxidizing agent; (b) an etching solution containing 1 to 20 mass % of a fluoride ion source; (c) 0.001 to 3 wt. % of a selectivity enhancer of formula S1; [Formula 1] TIFF2025506823000041.tif20122(d) 0.001 to 3 wt. % of an additional selectivity enhancer of formula S41; [chemical 2] TIFF2025506823000042.tif36109 or derivatives obtainable by homocondensation of a compound of formula S41 or by cocondensation of a compound of formula S41 with a silane of formula S42 in a mass ratio of 0.1 or more, and [C3] TIFF2025506823000043.tif32112(e) water; Including, In the formula, R S1 X S -OH and Y S -(CO)-OH; R S2 (i) R S1 , (ii) H, (iii) C1-C 10 Alkyl, (iv) C1-C 10 alkenyl, (v) C1-C 10 Alkynyl, and (vi)-X S1 -(O-C2H3R S6 ) m -OR S6 Selected from; R S6 is selected from H and C1-C6 alkyl; R S41 is unsubstituted or -NR S61 R S62 -OR S61 is a C1-C6 alkyl optionally substituted with; R S42 , R S43 are independently selected from C1-C6 alkoxy and C1-C6 alkyl, each of which is unsubstituted or -NR S61 R S62 -OR S61 Replaced with; R S51 , R S52 are independently unsubstituted or -NR S61 R S62 -OR S61 C1-C6 alkyl substituted with; R S61 , R S62 is independently selected from H and C1-C6 alkyl; X S is a linear or branched C1-C 10 Alkanediyl, linear or branched C2-C 10 Alkenyl, linear or branched C2-C 10 Alkynediyl, and -X S1 -(O-C2H3R S6 ) m - Selected from; Y S is a chemical bond and X S Selected from; X S1 is C1-C8 alkanediyl; m is an integer from 1 to 30.

Description

[Technical field]

[0001] The present invention relates to compositions, their use and methods for selectively etching silicon-germanium materials on a surface of a microelectronic device substrate versus etching silicon or silicon-germanium materials having lower germanium content on the same surface. [Background technology]

[0002] The preparation of certain microelectronic devices, such as integrated circuits, may involve the selective removal of silicon-germanium (SiGe) material from a surface that contains SiGe in combination with silicon (Si). According to a particular example fabrication process, SiGe is used as a sacrificial layer for structures that also contain silicon. Based on such fabrication processes, advanced device structures such as silicon nanowires and silicon-on-nothing (SON) structures can be prepared. These processes include epitaxial deposition of structures of alternating layers of Si and SiGe, followed by patterning, and finally selective lateral etching to remove the SiGe layers to produce three-dimensional silicon structures.

[0003] In a particular method of preparing field effect transistors (FETs) for integrated circuits, Si and SiGe materials are deposited as layers on a substrate, i.e., an "epitaxial stack" of Si and SiGe. The layers are then patterned using standard techniques, for example, by use of standard lithographically generated masks. A directional isotropic etch is then useful to laterally etch away the sacrificial SiGe material, leaving behind a silicon nanowire or sheet structure.

[0004] In other applications, SiGe with a low Ge content may need to be etched against SiGe with a high Ge content.

[0005] To enable smaller geometries in semiconductor structures, the electronics industry is looking for solutions to selectively remove the SiGe layer with respect to the amorphous or crystalline silicon, which is necessary to achieve well-defined nanowire or nanosheet structures.

[0006] EP 3 447 791 A1 discloses an etching solution for selectively removing silicon-germanium over polysilicon from microelectronic devices, comprising water, an oxidizing agent, a water-miscible organic solvent, a fluoride ion source, and optionally a surfactant. 2 O 2 , N.H. 4 F, butyl diclycol, citric acid, and Surfynol® 485, a polyethoxylated dialkylacetylene compound having an ethylene oxide content (mol) of 30, and an aid in suppressing poly-Si etch rate.

[0007] Unpublished International Patent Application No. PCT / EP2021 / 072975 discloses a composition for selectively etching a layer comprising a silicon germanium alloy (SiGe) in the presence of a layer comprising silicon, the composition comprising an etching solution comprising 5-15% by weight of an oxidizing agent, 5-20% by weight of a fluoride ion source, 0.001-3% by weight of an acetylenic hydroxy compound as a selectivity enhancer, and water.

[0008] However, the state-of-the-art solution is SiO x However, the etching rates of SiON or SiN are too high to meet all requirements. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] EP 3 447 791 A1 [Patent Document 2] PCT / EP2021 / 072975 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the object of the present invention is to maintain the SiGe / Si selectivity and to obtain a SiGe / SiO x , SiGe / SiON or SiGe / SiN selectivity, especially SiGe / SiO x The aim is to increase selectivity.

[0011] A further object of the present invention is to provide a method for manufacturing a SiGe / SiO x , SiGe / SiON or SiGe / SiN selectivity, especially SiGe / SiO x The objective is to increase the selectivity of etching high Ge content SiGe relative to low Ge content SiGe while maintaining or increasing the selectivity. [Means for solving the problem]

[0012] Currently, small amounts of silane compounds and their derivatives are used to x It has been found that the selectivity of SiGe / Si relative to SiON or SiN is significantly and selectively improved.

[0013] Accordingly, one embodiment of the present invention is a composition for selectively etching a first silicon germanium layer having a first germanium content in the presence of a silicon layer or a second silicon germanium layer having a second germanium content, where the first germanium content is higher than the second germanium content, the composition comprising: (a) 0.1 to 10 mass % of an oxidizing agent; (b) an etching solution containing 1 to 20 mass % of a fluoride ion source; (c) 0.001 to 3 wt. % of a selectivity enhancer of formula S1; [ka] (d) 0.001 to 3 wt. % of an additional selectivity enhancer of formula S41; [ka] or derivatives obtainable by homocondensation of a compound of formula S41 or by cocondensation of a compound of formula S41 with a silane of formula S42 in a mass ratio of 0.1 or more, and [ka] (e) water; Including, In the formula, R S1 X S -OH and Y S -(CO)-OH; R S2 (i) R S1 , (ii) H, (iii) C 1 ~C 10 alkyl, (iv) C 1 ~C 10 alkenyl, (v) C 1 ~C 10 Alkynyl, and (vi)-X S1 -(OC 2 H 3 R S6 ) m -OR S6 Selected from; R S6 H and C 1 ~C 6 alkyl; R S41 is unsubstituted or -NR S61 R S62 -OR S61 C may be substituted 1 ~C 6 is alkyl; R S42 , R S43 is independently 1 ~C 6 Alkoxy and C 1 ~C 6 alkyl, each of which is unsubstituted or -NR S61 R S62 -OR S61 Replaced with; R S51 , R S52 are independently unsubstituted or -NR S61 RS62 -OR S61 C replaced by 1 ~C 6 alkyl; R S61 , R S62 are independently H and C 1 ~C 6 alkyl; X S is a linear or branched C 1 ~C 10 Alkanediyl, linear or branched C 2 ~C 10 Alkenyl, linear or branched C 2 ~C 10 Alkynediyl, and -X S1 -(OC 2 H 3 R S6 ) m - Selected from; Y S is a chemical bond and X S Selected from; X S1 is C 1 ~C 8 It is an alkanediyl; m is an integer of 1 to 30, and preferably 10.

[0014] Particularly surprising was that the etching compositions according to the invention are suitable for enabling a very controlled and selective etching of layers comprising or consisting of SiGe alloys, preferably SiGe25 layers, but also thin or ultrathin layers comprising germanium ("Ge layers"), in particular layers comprising or consisting of SiGe alloys, while at the same time not significantly impairing or not impairing layers comprising or consisting of silicon (Si), in particular amorphous silicon or crystalline silicon, most in particular crystalline silicon. In particular SiGe / SiO x , SiGe / SiON and / or SiGe / SiN etching, especially SiGe / SiO x The selectivity of the reaction can be significantly improved.

[0015] Another embodiment of the present invention is a method of using the compositions described herein to selectively etch a first silicon germanium layer having a first germanium content in the presence of a silicon layer or a second silicon germanium layer having a second germanium content, and optionally a silicon oxide layer, where the first germanium content is higher than the second germanium content.

[0016] Yet another embodiment of the present invention is a method of selectively removing a first silicon germanium alloy layer having a first germanium content relative to a silicon layer or a second silicon germanium layer having a second germanium content and optionally a silicon oxide layer from a surface of a microelectronic device, where the first germanium content is greater than the second germanium content, the method comprising: (a) providing a microelectronic device surface comprising a layer comprising a silicon germanium alloy, a silicon layer, and optionally a silicon oxide layer; (b) providing a composition as described herein; and (c) contacting the surface with the composition for a time and at a temperature effective to selectively remove the silicon-germanium comprising layer relative to the layer comprising or consisting of Si, and optionally the silicon oxide layer. Includes.

[0017] Yet another embodiment of the present invention is a method for manufacturing a semiconductor device, wherein the method includes a method described herein, wherein a first silicon germanium alloy layer having a first germanium content is selectively removed from a surface relative to a silicon layer or a second silicon germanium layer having a second germanium content, and optionally a silicon oxide layer. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 shows a schematic diagram of the unetched substrate used in the examples. [Diagram 2] FIG. 2 shows the substrate obtained after carrying out Example 1. [Diagram 3]FIG. 3 shows the substrate obtained after carrying out Example 2. [Figure 4] FIG. 4 shows the substrate obtained after carrying out Example 3. [Diagram 5] FIG. 5 shows the substrate after HF pretreatment and before etching. [Figure 6] FIG. 6 shows the substrate obtained after carrying out Example 2 without HF pretreatment. [Figure 7] FIG. 7 shows the substrate obtained after carrying out Example 4. [Figure 8] FIG. 8 shows the substrate obtained after carrying out Example 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] The etching compositions according to the present invention are particularly useful for etching silicon-germanium containing layers in the presence of layers containing silicon, and are also useful for etching silicon oxide (SiO x ), is particularly useful when there is an additional layer comprising or consisting of SiON and / or SiN.

[0020] The etching composition, as further described below, comprises: (a) 0.1-10 wt. % of an oxidizing agent; (b) an etching solution comprising 1-20 wt. % of a fluoride ion source; and (c) 0.001-3 wt. % of a first selectivity enhancer of formula S1. [ka] (d) 0.001 to 3 wt. % of an additional selectivity enhancer of formula S41 [ka] or derivatives obtainable by homocondensation of a compound of formula S41 or by cocondensation of a compound of formula S41 with a silane of formula S42 in a mass ratio of 0.1 or more, and [ka] (d) water; Includes.

[0021] definition As used herein, "silicon layer" includes, but is not limited to, layers consisting essentially of elemental silicon, in particular amorphous or crystalline silicon (Si), p-doped silicon, and n-doped silicon. "Silicon layer" does not include silicon germanium alloys (SiGe). The term "consisting essentially of silicon" means that the silicon content in the layer is greater than 90% by weight, preferably greater than 95% by weight, and even more preferably greater than 98% by weight. When undoped silicon is used, it is particularly preferred that the silicon layer does not contain any other elements than silicon. When n- or p-doped silicon is used, it is particularly preferred that the silicon layer does not contain any other elements than n- or p-dopants, which may be present in an amount less than 10% by weight, preferably less than 2% by weight. Preferably, the germanium content of the silicon layer is less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, and even more preferably less than 0.1% by weight. Most preferably, the silicon layer does not contain germanium.

[0022] As used herein, the term "silicon oxide layer" or "SiO x The "layer" corresponds to a layer deposited from a silicon oxide precursor source, e.g., TEOS, thermally deposited silicon oxide, or carbon-doped oxide (CDO) deposited using commercially available precursors such as SiLK™, AURORA™, CORAL™, BLACK DIAMOND™, etc. "Silicon oxide" is meant to broadly include SiO&, CDO, siloxane, and thermal oxide. Silicon oxide or SiO x The material is pure silicon oxide (SiO 2 ) as well as impure silicon oxide containing impurities in its structure.

[0023] The term "silicon-germanium layer" or "SiGe layer" as used herein corresponds to a layer consisting essentially of a silicon-germanium (SiGe) alloy as known in the art. The term "consisting essentially of silicon" means that the SiGe content in the layer is greater than 90% by weight, preferably greater than 95% by weight, even more preferably greater than 98% by weight, and most preferably consists of SiGe. Silicon germanium or SiGe is generally represented by the formula SixGey, where x is in the range of about 0.50 to about 0.90, particularly about 0.60 to about 0.85 or about 0.70 to about 0.90, y is in the range of about 0.10 to about 0.50, particularly about 0.15 to about 0.40 or about 0.10 to about 0.30, and x+y=1.00. Here, the particularly preferred SiGe25 means that y is 0.25.

[0024] The term "selectively etches" (or "selective etch rate") as used herein preferably means that when a composition according to the invention is applied to a layer comprising or consisting of a first material, in this case SiGe, in the presence of a layer comprising or consisting of a second material, in this case silicon, in particular Si, most particularly aSi, the etch rate of said composition for etching the first layer is significantly higher compared to the etch rate of said composition for the second layer. Depending on the substrate to be etched, silicon, e.g. SiO x Neither should other layers comprising or consisting of SiON or SiN be at risk.

[0025] The SiGe / Si selectivity is greater than 500, preferably greater than 750, and most preferably greater than 1000. The SiGe / SiGe selectivity is greater than 10, preferably greater than 20, and most preferably greater than 50.

[0026] As used herein, the term "layer" refers to a portion of a substrate that is separately disposed on a surface of the substrate and has a distinct composition relative to adjacent layers.

[0027] As used herein, "chemical bond" means that the respective moieties are not present, but adjacent moieties are bridged to form a direct chemical bond between the adjacent moieties. As an example, in a molecule ABC, when moiety B is a chemical bond, adjacent moieties A and C together form a group AC.

[0028] "C x The term "C" means that each group contains x C atoms. x ~C y The term "alkyl" means an alkyl having x to y carbon atoms, and includes unsubstituted straight chain, branched and cyclic alkyl, unless expressly specified. As used herein, "alkyl" refers to a straight chain, branched or cyclic alkyl, or combinations thereof. As used herein, "alkanediyl" refers to a diradical of a straight chain, branched or cyclic alkane, or combinations thereof.

[0029] All percentages, ppm, or equivalent values ​​refer to weight relative to the total weight of the respective composition unless otherwise indicated. The term "wt%" refers to % by weight.

[0030] All cited references are incorporated herein by reference.

[0031] Oxidizing agent The etching composition according to the present invention includes an oxidizer, also referred to as an "oxidizer," which may be one or more compounds capable of oxidizing germanium in a silicon germanium alloy.

[0032] Preferably, the oxidizing agent is different from the other components of the composition, and in particular different from the etchant. Thus, the oxidizing agent preferably does not include a source of fluoride ions.

[0033] Oxidizing agents contemplated herein include hydrogen peroxide, FeCl 3 , FeF 3 , Fe(NO 3 ) 3, Sr(NO 3 ) 2 , CoF 3 , MnF3, Oxone (2KHSO 5 KHSO 4 K 2 SO 4 ), periodic acid, iodic acid, vanadium(V) oxide, vanadium(IV,V) oxide, ammonium vanadate, ammonium peroxymonosulfate, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium nitrate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, ammonium hypochlorite, ammonium hypobromite, ammonium tungstate, sodium persulfate, sodium hypochlorite, sodium perborate, sodium hypobromite, potassium iodate, potassium permanganate, potassium persulfate, nitric acid, potassium persulfate, potassium hypochlorite, tetramethylammonium chlorite, tetramethylammonium chlorate, Examples of suitable oxidizing species include, but are not limited to, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, tetrabutylammonium peroxymonosulfate, peroxymonosulfate, ferric nitrate, urea hydrogen peroxide, peracetic acid, methyl-1,4-benzoquinone (MBQ), 1,4-benzoquinone (BQ), 1,2-benzoquinone, 2,6-dichloro-1,4-benzoquinone (DCBQ), toluquinone, 2,6-dimethyl-1,4-benzoquinone (DMBQ), chloranil, alloxan, N-methylmorpholine N-oxide, trimethylamine N-oxide, and combinations thereof. The oxidizing species may be introduced into the composition at the manufacturer prior to introducing the composition into the device wafer, or may be introduced into the device wafer, i.e., in situ.

[0034] Preferably, the oxidizing agent comprises or consists of a peroxide. Useful peroxides may be, but are not limited to, hydrogen peroxide or peroxymonosulfuric acid, and organic acid peroxides, such as peroxyacetic acid, and salts thereof.

[0035] The most preferred oxidizing agent is hydrogen peroxide.

[0036] The oxidizing agent can be used in an amount of about 1 to about 20% by mass, preferably about 1.5 to about 14% by mass, more preferably about 2 to about 12% by mass, even more preferably about 3 to about 11% by mass, and most preferably about 4 to about 6% by mass, based on the total mass of the composition.

[0037] Etching solution The etching composition according to the present invention includes a source of fluoride ions, which may be any compound capable of releasing fluoride ions.

[0038] Preferably, the etching solution is different from the other components in the composition, in particular from the oxidizing agent, and therefore preferably does not have any oxidizing ability towards the material of the substrate surface to be treated, in particular towards Si or SiGe.

[0039] Preferred etchants are selected from the group consisting of, but not limited to, ammonium fluoride, ammonium difluoride, triethanolammonium fluoride, diglycolammonium fluoride, methyldiethanolammonium fluoride, tetramethylammonium fluoride, triethylamine trihydrofluoride, hydrogen fluoride, fluoroboric acid, tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic acid, ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate, and mixtures thereof.

[0040] The etching solution preferably comprises one or more of the above compounds, most preferably one of the above compounds.

[0041] Most preferably, the etching solution comprises or consists of ammonium fluoride, ammonium bifluoride, and hydrogen fluoride.Most preferably, the etching solution comprises or consists of ammonium fluoride.

[0042] The etching composition according to the invention, comprising ammonium fluoride as an etchant, has demonstrated a stable, reproducible and controlled selective etching rate for etching SiGe, in particular a layer comprising or consisting of SiGe25, in the presence of a layer comprising or consisting of Si.

[0043] The etching solution can be used in an amount of about 0.1 to about 14 mass %, preferably about 1 to about 12 mass %, more preferably about 3 to about 10 mass %, even more preferably about 4 to about 10 mass %, and most preferably about 6 to about 8 mass %, based on the total mass of the composition.

[0044] The compositions according to the invention, including the preferred total amounts of etchant defined herein, have demonstrated excellent etch rates and etch rate selectivities for etching a layer comprising or consisting of SiGe, preferably SiGe25, in the presence of a layer comprising or consisting of Si.

[0045] SiGe selectivity enhancer The first SiGe selectivity enhancer (also referred to as the “selectivity enhancer”) of formula S1 is [ka] The etch rate of layers containing or consisting of Si is selectively reduced, but the etch rate of layers containing or consisting of SiGe, preferably SiGe25, remains high, resulting in a SiGe / Si, and especially SiG2 / a-Si, selectivity of more than 500, or even more than 1000.

[0046] In formula S1, R S1 X S -OH and Y S -(CO)-OH, where X S is a linear or branched C 1 ~C 10 Alkanediyl, linear or branched C 2 ~C 10 Alkenyl, linear or branched C 2~C 10 Alkynediyl or polyoxyalkylene group -X S1 -(OC 2 H 3 R S6 ) m - and Y S1 X S It may be the same as a chemical bond or the same as a S1 When X is a polyoxyalkylene group, S1 is C 1 ~C 8 Alkanediyl, preferably C 1 ~C 6 and m is an integer selected from 1 to 30, preferably 1 to 20, most preferably 1 to 15. The larger m is, the less effective the selectivity enhancer is for Si relative to SiGe. If m is too high, the selectivity enhancer will be a-Si, SiO x , the etching rate of SiON or SiN is not sufficiently decreased. For etching of SiGe relative to SiGe, a high m value of 5 to 20, or 20 to 40, is preferred.

[0047] R S2 is R S1 and preferably, R S2 is the above R S1 is the same as:

[0048] Or, R S2 (ii) H, (iii) C 1 ~C 10 alkyl, (iv) C 1 ~C 10 alkenyl, (v) C 1 ~C 10 Alkynyl, and (vi)-X S1 -(OC 2 H 3 R S6 )m-OR S6 where X is S1 is C 1 ~C 6alkanediyl, preferably ethanediyl, propanediyl or butanediyl; R S6 H and C 1 ~C 6 alkyl, preferably selected from H, methyl or ethyl; m is an integer from 1 to 30.

[0049] Most preferably, R S1 and R S2 are the same thing.

[0050] In a first preferred embodiment, R S1 X S X may be -OH. S is preferably C 1 ~C 8 Alkanediyl, more preferably C 1 ~C 6 It may be alkane-1,1-diyl.

[0051] Preferably, X S is C 3 ~C 10 Alkanediyl, more preferably C 4 ~C 8 alkanediyl.

[0052] Particularly preferably, X S is selected from methanediyl, ethane-1,1-diyl, and ethane-1,2-diyl. S is selected from propane-1,1-diyl, butane-1,1-diyl, pentane-1,1-diyl, and hexane-1,1-diyl. S is selected from propane-2,2-diyl, butane-2,2-diyl, pentane-2,2-diyl, and hexane-2,2-diyl. S is selected from propane-1,2-diyl, butane-1,2-diyl, pentane-1,2-diyl, and hexane-1,2-diyl. Sis selected from propane-1,3-diyl, butane-1,3-diyl, pentane-1,3-diyl and hexane-1,3-diyl. Particularly preferred groups X S are butane-1,1-diyl, pentane-1,1-diyl, and hexane-1,1-diyl, heptane-1,1-diyl, and octane-1,1-diyl.

[0053] Preferably, the first selectivity enhancer is a compound of formula S2 [ka] (In the formula, R S11 , R S21 is independently 1 ~C 10 selected from alkyl, preferably from ethyl, propyl, butyl, pentyl and hexyl, most preferably from propyl, butyl or pentyl; R S12 , R S22 are independently H and C 1 ~C 4 alkyl, preferably selected from H, methyl or ethyl).

[0054] When etching SiGe relative to Si, most preferably the (first) selectivity enhancer is a compound of formula S4, available from Evonik under the trade name Surfynol® 104.

[0055] [ka]

[0056] When etching SiGe with a higher Ge content relative to SiGe with a lower Ge content, most preferably the (first) selectivity enhancer may be a compound of formula S5: [ka] (In the formula, R S11 , R S21 is independently 1 ~C10 selected from alkyl, preferably from ethyl, propyl, butyl, pentyl and hexyl, most preferably from propyl, butyl or pentyl; R S12 , R S22 are independently H and C 1 ~C 4 alkyl, preferably selected from H, methyl or ethyl; k, l are independently integers selected from 1 to 30, preferably 1 to 20, most preferably 1 to 15, and advantageously the sum of k and l is about 5 to 20 or about 20 to 40).

[0057] Such compounds are available commercially from Evonik under the trade names Surfynol® 465 and Surfynol® 485 W.

[0058] The selectivity enhancer of the first preferred embodiment can be present in an amount of about 0.0005 to about 0.03 wt%, preferably about 0.001 to about 0.02 wt%, and most preferably about 0.005 to about 0.015 wt%. A single selectivity enhancer can increase the SiGe / Si selectivity to 500 or more, preferably 750 or more, and most preferably 1000 or more. A single selectivity enhancer can also increase the SiGe / SiGe selectivity to 10 or more, preferably 20 or more, and most preferably 50 or more.

[0059] In a second preferred embodiment, R S1 is Y S -(CO)-OH, where Y S1 may be a chemical bond, or the above-mentioned X S may be the same as

[0060] Preferably, the (first) selectivity enhancer is a compound of formula S3.

[0061] [ka]

[0062] The selectivity enhancer of the second preferred embodiment can be present in an amount of from about 0.1 to about 3 wt %, preferably from about 0.5 to about 2 wt %.

[0063] Compositions according to the present invention may include one or more of the selectivity enhancers described herein.

[0064] Particularly preferred compositions comprise one single selectivity enhancer of the first preferred embodiment, in particular one single selectivity enhancer of formula S2 or formula S4.

[0065] Another particularly preferred composition comprises a first selectivity enhancer of the first preferred embodiment, particularly a first selectivity enhancer of formula S2 or formula S4; and further comprises a second selectivity enhancer of the second preferred embodiment, particularly a second selectivity enhancer of formula S3. When a first selectivity enhancer of formula S2 or formula S4 and a second selectivity enhancer of formula S3 are used, the mass ratio of the first selectivity enhancer to the second selectivity enhancer is preferably 0.0001 to 0.1, most preferably 0.001 to 0.02. The combination of the first selectivity enhancer and the second selectivity enhancer can improve the SiGe / Si selectivity by 10 to 100%. 4 It can be increased to more than that.

[0066] Additional SiGe selectivity enhancers The composition includes silane as an additional SiGe selectivity enhancer. Silane enhances SiGe selectivity relative to silicon-containing layers, particularly SiGe / SiO x , further enhancing the SiGe / SiON or SiGe / SiN selectivity, and also functions as a hardmask protectant, which significantly improves the hardmask compatibility of the SiGe etching composition.

[0067] In a first embodiment, monomeric silanes of formula S41 can be used: [ka] (In the formula, R S41 is unsubstituted or -NR S61 R S62 -OR S61C may be substituted 1 ~C 6 is alkyl; R S42 , R S43 is independently 1 ~C 6 Alkoxy and C 1 ~C 6 alkyl, each of which is unsubstituted or -NR S61 R S62 -OR S61 Replaced with; R S51 , R S52 are independently unsubstituted or -NR S61 R S62 -OR S61 C replaced by 1 ~C 6 alkyl).

[0068] In a preferred embodiment, R S41 is C 1 ~C 5 Alkyl, preferably C 1 ~C 4 Alkyl, even more preferably methyl, ethyl or propyl, most preferably methyl or ethyl.

[0069] In a first preferred alternative embodiment, R S42 is C 1 ~C 5 Alkyl, preferably C 1 ~C 4 alkyl, even more preferably methyl, ethyl or propyl, most preferably methyl or ethyl. In a second preferred alternative embodiment, R S42 is C 1 ~C 5 Alkoxy, preferably C 1 ~C 4 Alkoxy, even more preferably methoxy, ethoxy or propoxy, most preferably methoxy or ethoxy.

[0070] In a preferred embodiment, R S51 and R S52is independently 1 ~C 5 Alkyl, preferably C 1 ~C 4 Alkyl, even more preferably methyl, ethyl or propyl, most preferably methyl or ethyl.

[0071] All substituents R S41 , R S42 , R S51 and R S52 is unsubstituted or has one or more -NR S61 R S62 OR S6 and may be substituted by, preferably unsubstituted or one or more -NH 2 , -NHR S71 , and -NHR S71 R S72 where R S71 and R S71 are independently methyl, ethyl, propyl or butyl. Most preferably, all substituents R S41 , R S42 , R S51 and R S52 is non-substitutive.

[0072] In a preferred embodiment, a silane of formula S49 can be used: [ka] (In the formula, R S51 , R S52 , R S53 is independently selected from methyl, ethyl, propyl and butyl, preferably methyl and ethyl; R S41 is selected from methyl, ethyl, propyl and butyl, preferably methyl and ethyl).

[0073] All substituents R S41 , R S51 , R S52 , and R S53 is unsubstituted or has one or more -NR S61 R S62 OR S6and may be substituted by, preferably unsubstituted or one or more -NH 2 , -NHR S71 , and -NHR S71 R S72 where R S71 and R S71 are independently methyl, ethyl, propyl or butyl. Most preferably, all substituents R S41 , R S51 , R S52 , and R S53 is non-substitutive.

[0074] Particularly preferred is methyltrimethoxysilane.

[0075] [ka]

[0076] In a second embodiment, the composition comprises a derivative of the above monomeric silanes obtainable by homocondensation of a compound of formula S41 or by cocondensation of a compound of formula S41 with a silane of formula S42 in a mass ratio of at least 0.1, preferably at least 0.2, even more preferably at least 0.3 and most preferably at least 0.5.

[0077] [ka]

[0078] Such silane condensation products are also formed when using monomeric silanes of formula 41 above. Typically, due to the low concentrations used in the compositions, a low average degree of polymerization of about 10 or less, preferably about 5 or less, and most preferably about 3 or less, is expected. When using aqueous etching compositions, monomeric silanes may also hydrolyze to some extent.

[0079] One type of homocondensate is a linear silane of formula S43: [ka] (In the formula, e is an integer of 0 to 5, preferably 0, 1 or 2, and most preferably 1); or a co-condensate of formula S44, [ka] In the formula, e is an integer of 0 to 5, preferably 0, 1 or 2, and most preferably 1; S43 -OR S51 (It is.)

[0080] Substituent R S43 is unsubstituted or has one or more -NR S61 R S62 OR S6 and may be substituted by, preferably unsubstituted or one or more -NH 2 , -NHR S61 It may be substituted by, and is most preferably unsubstituted.

[0081] Another type of homocondensate is the branched silane of formula S45: [ka] (In the formula, u, v, and w are independently an integer selected from 0 to 5, preferably 0, 1, 2, or 3, and most preferably 0 or 1; y is an integer from 1 to 5, preferably 1 or 2, and most preferably 1; or a co-condensate of formula S46, [ka] (In the formula, u, v, and w are independently an integer selected from 0 to 5, preferably 0, 1, 2, or 3, and most preferably 0 or 1; y is an integer from 1 to 5, preferably 1 or 2, and most preferably 1; At least one, preferably two R S43 -OR S51 (It is.)

[0082] Yet another type of homocondensate is a cyclic silane of formula S47: [ka] (wherein n is 0, 1 or 2, preferably 0 or 1, most preferably 1). or a co-condensate of formula S48.

[0083] [ka]

[0084] The concentrations of the silanes of formulas S41 to S48 may generally range from about 0.001 to about 3% by weight, preferably from about 0.005 to about 2% by weight, even more preferably from about 0.05 to about 1% by weight, and most preferably from about 0.1 to about 0.5% by weight, based on the total weight of the composition.

[0085] Although one or more silanes may be present in the composition, it is preferred to use only one of the additives of formulae S41-S48.

[0086] acid The etching composition according to the present invention may further comprise an acid. Such an acid may be an inorganic acid, an organic acid, or a combination thereof. Preferably, the acid is an organic acid, or a combination of an inorganic acid and an organic acid.

[0087] Exemplary inorganic acids may be selected from, but are not limited to, sulfuric acid or phosphoric acid. Preferably, the inorganic acid comprises or consists of a strong inorganic acid, in particular sulfuric acid.

[0088] Typical organic acids are C 1 ~C 10 The carboxylic acid may be selected from, but is not limited to, mono-, di- or tri-carboxylic acids, sulfonic acids, phosphonic acids, etc. 1 ~C 10 The carboxylic acids are mono-, di- or tricarboxylic acids.

[0089] In a preferred embodiment, the acid comprises or consists of a hydroxycarboxylic acid, in particular, but not limited to, citric acid or tartaric acid. In another preferred embodiment, no additional acid is required since acetylenic compounds, such as, but not limited to, acetylenedicarboxylic acid, also have acidic properties. Particularly preferred are acetic acid, phosphoric acid, and tartaric acid.

[0090] When present, the acid can be used in the etching composition in an amount of from about 0.1% to about 5% by weight, more preferably from about 0.2% to about 4% by weight, even more preferably from about 0.3% to about 3% by weight, and most preferably from about 0.5% to about 2% by weight.

[0091] Organic Solvents Although not preferred, the etching composition may optionally contain one or more organic solvents.

[0092] In each case, the compositions according to the invention as defined herein may further comprise, as optional additional components: one or more water-miscible organic solvents, preferably selected from the group consisting of tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylsulfoxide (DMSO), ethanol, isopropanol, butyl diglycol, butyl glycol, sulfolane (2,3,4,5-tetrahydrothiophene-1,1-dioxide) and mixtures thereof; more preferably selected from the group consisting of THF, NMP, DMF, DMSO, sulfolane and mixtures thereof.

[0093] The term "water-miscible organic solvent" in the context of the present invention preferably means that an organic solvent fulfilling this requirement is miscible with water in a ratio of at least 1:1 (w / w) at 20° C. and ambient pressure. Preferably, the at least one water-miscible organic solvent (H) is sulfolane. In particular, compositions according to the invention that do not comprise one or more water-miscible organic solvents are preferred.

[0094] In each individual case, it is preferred that the compositions according to the invention as defined herein (or those compositions according to the invention described above or below as being preferred) have a total amount of one or more water-miscible organic solvents (i.e. solvent components) present of from about 0.1 to about 30% by weight, preferably from about 0.5 to about 10% by weight, more preferably from about 1 to about 7.5% by weight, even more preferably from about 1 to about 6% by weight, based on the total weight of the composition.

[0095] Most preferably, the etching composition is an aqueous solution essentially free of organic solvents, where essentially free means herein that the organic solvent content is less than 1% by weight, preferably less than 0.1% by weight, even more preferably less than 0.01% by weight, and most preferably below the detection limit.

[0096] Surfactants The composition may also further comprise one or more surfactants.

[0097] Preferred surfactants are selected from the group consisting of: (i) anionic surfactants, preferably selected from the group consisting of ammonium lauryl sulfate, fluorosurfactants, preferably perfluorinated alkylsulfonamide salts (preferably perfluorinated, N-substituted alkylsulfonamide ammonium salts, PNAAS), perfluorinated octanesulfonates, perfluorinated butanesulfonates, perfluorinated nonanoates and perfluorinated octanoates; alkyl-aryl ether phosphates and alkyl ether phosphates; (ii) a zwitterionic surfactant, preferably selected from the group consisting of (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) ("CHAPS"), cocamidopropyl hydroxysultaine (CAS RN 68139-30-0), {[3-(dodecanoylamino)propyl](dimethyl)-ammonio}acetate, phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine; and (iii) Non-ionic surfactants, preferably selected from the group consisting of glucoside alkyl ethers, glycerol alkyl ethers, cocamide ethanolamine and lauryl dimethylamino oxide.

[0098] More preferred surfactants in the compositions according to the invention are or contain perfluorinated N-substituted alkylsulfonamide ammonium salts. Preferred surfactants (E) in the compositions according to the invention do not contain metals or metal ions.

[0099] Particularly preferred surfactants are those of formula F1: [ka] (In the formula, X F2 is C 1 ~C 4 It is an alkanediyl; R F4 is C 12 ~C 30 Alkyl or C 12 ~C 30 alkenyl; R F5 is C 1 ~C 4 (It is alkyl).

[0100] The compositions according to the invention as defined herein also preferably have one or more surfactants present in an amount of from about 0.0001 to about 1% by weight, preferably from about 0.0005 to about 0.5% by weight, more preferably from about 0.001 to about 0.01% by weight, based on the total weight of the composition.

[0101] Chelating Agents The etching composition may optionally include one or more chelating agents.

[0102] Preferred chelating agents include 1,2-cyclohexylene dinitrilotetraacetic acid, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, acetylacetonate, 2,2'-azanediyldiacetic acid, ethylenediaminetetraacetic acid, etidronic acid, methanesulfonic acid, acetylacetone, 1,1,1-trifluoro-2,4-pentanedione, 1,4-benzoquinone, 8-hydroxyquinoline, salicylideneaniline; tetrachloro-1,4-benzoquinone, 2-(2-hydroxyphenyl)-benzoxazole, 2-(2-hydroxyphenyl)-benzothiazole, hydroxyquinolinesulfonic acid, sulfosalicylic acid, salicylic acid, pyridine, 2-ethylpyridine, 2-methoxypyridine, 3-methoxypyridine, 2-picoline, dimethylpyridine, piperidine, piperazine, triethylamine, triethanolamine, ethylamine, methylamine, isobutylamine, tert-butylamine, tributylamine, dipropylamine, dimethylamine, diglycolamine, monoethanolamine, methyldiethanolamine, pyrrole, isoxazole, bipyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, indole, 1-methylimidazole, diisopropylamine, diisobutylamine, aniline, pentamethyldiethylenetriamine, acetoacetamide, ammonium carbamate, ammonium pyrrolidine dithiocarbamate, dimethyl malonate, methyl acetoacetate, N-methylacetoacetamide, tetramethylammonium thiobenzoate, 2,2,6,6-tetramethyl-3,5-heptanedione, tetramethylthiuram disulfide, lactic acid, ammonium lactate, formic acid, propionic acid, gamma-butyrolactone, and mixtures thereof.

[0103] In a preferred embodiment, the chelating agent may be diethylenetriaminepentaacetic acid (DTPA) or may include DTPA and one or more of the other chelating agents listed above. Compositions including DTPA as a chelating agent have shown particularly low etching rates for silicon oxide.

[0104] The compositions according to the invention as defined herein also preferably have one or more chelating agents present in an amount of from about 0.005 to about 2% by weight, preferably from about 0.01 to about 1% by weight, more preferably from about 0.02 to about 0.2% by weight, based on the total weight of the composition.

[0105] composition In a preferred embodiment, the pH of the etching composition is 4 to 8, in particular 5 to 7. If the pH is too low, the etching rate of silicon oxide will be too high, and if the pH is too high, the etching rate of Si will be too high. The pH of the bath can be adjusted by a pH adjuster, in particular ammonia.

[0106] It is particularly preferred that the composition according to the invention as defined herein consists of hydrogen peroxide, ammonium fluoride, a first selectivity enhancer of formula S2 or S4, optionally a second selectivity enhancer of formula S3, an additional selectivity enhancer of formula S41, optionally an acid, optionally a pH adjuster, and water, as defined herein and based on the examples.

[0107] It is particularly preferred that the composition according to the invention as defined herein consists of hydrogen peroxide, ammonium fluoride, a first selectivity enhancer of formula S3, optionally a surfactant of formula S4, an additional selectivity enhancer of formula S41, optionally an acid, optionally a pH adjuster, and water, as defined herein and based on the examples.

[0108] The following, all based on the total weight of the composition: (a) one or more oxidizing agents selected from peroxides, preferably one or more oxidizing agents consisting of or including hydrogen peroxide, in an amount of about 1 to about 2% by weight, more preferably about 2 to about 12% by weight, even more preferably about 3 to about 7% by weight, and most preferably about 4 to about 6% by weight; (b) one or more etching solutions comprising a fluoride ion source selected from the group consisting of ammonium fluoride, ammonium bifluoride, triethanolammonium fluoride, diglycolammonium fluoride, methyldiethanolammonium fluoride, tetramethylammonium fluoride, triethylamine trihydrofluoride, hydrogen fluoride, fluoroboric acid, tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic acid, ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate, and mixtures thereof, in an amount of about 0.1 to about 14% by weight, preferably about 1 to about 12% by weight, more preferably about 3 to about 10% by weight, even more preferably about 4 to about 10% by weight, and most preferably about 6 to about 8% by weight, and preferably consisting of or comprising ammonium fluoride, hydrogen fluoride, or a combination thereof; (c) a first selectivity enhancer of formula S1, particularly formula S2, S3, or S4, in an amount of about 0.0005 to about 0.02 wt. %, preferably about 0.005 to about 0.015 wt. %; (d) optionally, if the first selectivity enhancer is not a compound of formula S3, a second selectivity enhancer of formula S3 in an amount of from about 0.1 to about 3 wt. %, preferably from about 0.5 to about 2 wt. %; (e) an amount of 0.01 to 5% by weight, preferably 0.1 to 1% by weight, of an additional selectivity enhancer of formula S41 or a derivative thereof obtained by homocondensation of a compound of formula S41 or by cocondensation of a compound of formula S41 with a silane of formula S42 in a mass ratio of 0.1 or more; (f) an inorganic acid and an organic acid, preferably an organic acid, more preferably C, in an amount of about 0.1% by weight to about 5% by weight, more preferably about 0.2% by weight to about 4% by weight, even more preferably about 0.3% by weight to about 3% by weight, and most preferably about 0.5% by weight to about 2% by weight; 1 ~C 10 one or more acids selected from mono-, di- or tricarboxylic acids, even more preferably hydroxycarboxylic acids, even more preferably dihydroxydicarboxylic acids, most preferably tartaric acid, or combinations thereof, preferably consisting of or including tartaric acid; (g) optionally, in an amount of about 0.0005 to about 0.5% by weight, more preferably about 0.001 to about 0.01% by weight, of (i) preferably an anionic surfactant selected from the group consisting of ammonium lauryl sulfate, fluorosurfactants, preferably perfluorinated alkylsulfonamide salts (preferably perfluorinated, N-substituted alkylsulfonamide ammonium salts), perfluorinated octanesulfonates, perfluorinated butanesulfonates, perfluorinated nonanoates, and perfluorinated octanoates; alkyl-aryl ether phosphates, and alkyl ether phosphates; (ii) preferably (3-[(3 (iii) a zwitterionic surfactant selected from the group consisting of {[3-(dodecanoylamino)propyl](dimethyl)ammonio}-1-propanesulfonate), cocamidopropyl hydroxysultaine, {[3-(dodecanoylamino)propyl](dimethyl)ammonio}acetate, phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine; (iv) a non-ionic surfactant, preferably selected from the group consisting of glucoside alkyl ethers, glycerol alkyl ethers, cocamidoethanolamine and lauryl dimethylamino oxide; and one or more surfactants, preferably being or comprising a compound of formula F1; (h) optionally, diethylenetriaminepentaacetic acid, 1,2-cyclohexylenedinitrilotetraacetic acid, 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, acetylacetonate, 2,2'-azanediyldiacetic acid, ethylenediaminetetraacetic acid, etidronic acid, methanesulfonic acid, acetylacetone, 1,1,1-trifluoro-2,4-pentanedione, in an amount of about 0.005 to about 2% by weight, preferably in a total amount of about 0.01 to about 1% by weight, and more preferably in a total amount of about 0.02 to about 0.2% by weight, based on the total weight of the composition; dione, 1,4-benzoquinone, 8-hydroxyquinoline, salicylideneaniline; tetrachloro-1,4-benzoquinone, 2-(2-hydroxyphenyl)-benzoxazole, 2-(2-hydroxyphenyl)-benzothiazole, hydroxyquinolinesulfonic acid, sulfosalicylic acid, salicylic acid, pyridine, 2-ethylpyridine, 2-methoxypyridine, 3-methoxypyridine, 2-picoline, dimethylpyridine, piperidine, piperazine, triethylamine, triethanolamine, ethylamine, methyl Amines, isobutylamine, tert-butylamine, tributylamine, dipropylamine, dimethylamine, diglycolamine, monoethanolamine, methyldiethanolamine, pyrrole, isoxazole, bipyridine, pyrimidine, pyrazine, pyridazine, quinoline, isoquinoline, indole, 1-methylimidazole, diisopropylamine, diisobutylamine, aniline, pentamethyldiethylenetriamine, acetoacetamide, ammonium carbamate, pyrrolidine dithiocarbamate one or more chelating agents selected from the group consisting of ammonium lactate, dimethyl malonate, methyl acetoacetate, N-methylacetoacetamide, tetramethylammonium thiobenzoate, 2,2,6,6-tetramethyl-3,5-heptanedione, tetramethylthiuram disulfide, lactic acid, ammonium lactate, formic acid, propionic acid, gamma-butyrolactone, and mixtures thereof, preferably being or including 1,2-cyclohexylene dinitrilotetraacetic acid; (k) water, in each case as the balance up to a total of 100% by weight of the composition; and (l) optionally, one or more water-miscible organic solvents, preferably selected from the group consisting of tetrahydrofuran (THF), N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylsulfoxide (DMSO), sulfolane (2,3,4,5-tetrahydrothiophene-1,1-dioxide), and mixtures thereof, in an amount of about 0.1 to about 30%, preferably about 0.5 to about 10%, more preferably about 1 to about 7.5%, and even more preferably about 1 to about 6% by weight; Particularly preferred are compositions comprising or consisting of, wherein the pH of the composition is from about 4 to about 8, preferably from about 5 to about 7, and in each case the weight percentages of the components sum to 100 weight %.

[0109] application In a first embodiment, the composition is particularly useful for selectively etching silicon layers, especially crystalline Si, and preferably layers comprising silicon germanium alloy (SiGe) in the presence of silicon oxide.

[0110] In a second embodiment, the composition is particularly useful for selectively etching a silicon germanium alloy having a first germanium content in the presence of a silicon germanium alloy having a second germanium content, preferably in the presence of silicon oxide, where the first germanium content is higher than the second germanium content.

[0111] In a second embodiment, the first germanium content is at least 5% by weight higher than the second germanium content, preferably 10% by weight, more preferably 15% by weight, most preferably 20% by weight higher. It is particularly preferred to etch SiGe40 rather than SiGe20.

[0112] It will be understood that it is common practice to make compositions in concentrated form and dilute them before use. For example, the compositions may be manufactured in a more concentrated form and then diluted with water, at least one oxidizing agent, or other ingredients at the manufacturer before and / or during use. The dilution ratio may range from about 0.1 parts diluent to 1 part composition concentrate to about 100 parts diluent to 1 part composition concentrate.

[0113] Thus, one embodiment relates to a kit comprising one or more components adapted to form a composition as described herein, in one or more containers. Preferably, one container comprises at least one oxidizing agent, and a second container comprises the remaining components for combination at the time of manufacture or use, such as at least one etchant, at least a selectivity enhancing agent, water, and optionally other components as described herein.

[0114] In using the compositions described herein, the composition is typically contacted with the device structure for a sufficient period of time, from about 3 minutes to about 60 minutes, preferably from about 5 minutes to about 20 minutes, in a batch process, and from about 20 seconds to about 5 minutes, preferably from about 30 seconds to about 3 minutes, in a single wafer process.

[0115] In using the compositions described herein, the compositions are typically contacted with the device structure at a temperature ranging from about 10°C to about 80°C, preferably from about 20°C to about 60°C. Such contact times and temperatures are exemplary, and any other suitable time and temperature conditions effective to achieve the required removal selectivity can be employed. One advantage of the compositions according to the invention is that the SiGe / Si etch ratio has a low temperature dependence. In particular, the SiGe etch rate and the SiGe / Si etch ratio are still very high at temperatures below 30°C, such that the substrate is processed at room temperature.

[0116] After achievement of the desired etching effect, the composition can be easily removed from the microelectronic device to which it was previously applied, for example, by rinsing, cleaning, or other removal step(s) as desired and effective in a given end use application of the inventive composition. For example, the device can be rinsed with a rinse solution comprising deionized water, an organic solvent, and / or dried (e.g., spin-drying, N 2 , steam drying, etc.).

[0117] It may be useful to rinse the blanket wafer surface with an aqueous solution containing 0.1% to 1% by weight of HF at room temperature for about 30 seconds, then immerse in UPW for 2 to 3 seconds and dry with compressed air. However, by using the composition according to the invention, it is possible and preferred to omit such pretreatment with HF.

[0118] The etching compositions described herein can be advantageously used to selectively etch a layer comprising SiGe in the presence of a layer comprising or consisting of Si, and in the presence of a layer comprising or consisting of silicon oxide.

[0119] The etching compositions described herein can be advantageously used in a method for selectively removing a layer comprising or consisting of a silicon germanium alloy relative to a layer comprising or consisting of Si and a layer comprising or consisting of silicon oxide from a surface of a microelectronic device, the method comprising the steps of: (a) providing a surface of a microelectronic device comprising a layer comprising a silicon germanium alloy, a layer comprising or consisting of Si, and a layer comprising or consisting of silicon oxide; (b) providing a composition as described above; (c) contacting the surface with the composition for a time and at a temperature effective to selectively remove the silicon-germanium comprising layer relative to layers comprising or consisting of Si and layers comprising or consisting of silicon oxide; Includes.

[0120] Preferably, the SiGe etch rate of the composition according to the present invention is 200 A / min or more, more preferably 300 A / min or more. Preferably, the Si etch rate of the composition according to the present invention is 2 A / min or less, more preferably 1 A / min or less. Preferably, the SiO x The etch rates of SiN and SiON are 2 A / min or less, more preferably 1 A / min or less. Preferably, the etch rate of the silicon-germanium containing layer is at least 200 times faster than the etch rate of the silicon layer, preferably at least 500 times, more preferably at least 750 times, even more preferably at least 1000 times, even more preferably at least 2000 times, and most preferably more than 5000 times faster (SiGe / Si selectivity).

[0121] The etching compositions described herein can be advantageously used in semiconductor device manufacturing processes that include selective removal of silicon-germanium from surfaces of microelectronic devices relative to materials that include or consist of Si and materials that include or consist of silicon oxide.

[0122] All percentages, ppm, or equivalent amounts are by weight based on the total weight of the respective composition unless otherwise indicated. All citations are incorporated herein by reference.

[0123] The following examples further illustrate the invention without limiting its scope. EXAMPLES

[0124] The following substrates were used in Examples 1 to 3: SALSA III manufactured by IMEC, as shown diagrammatically in Figure 1. These substrates comprise multiple stacked SiGe and Si layers. The SALSA III layers are stacked from top to bottom: SiO 2 (50 nm)-SiN(50 nm)-SiO 2(5nm)-Si(25nm)-SiGe(25nm)-Si(20nm)-SiGe(20nm)-Si(15nm)-SiGe(15nm)-Si(10nm)-SiGe(10nm)-Si(5nm)-SiGe(5nm)-Si <100> Wafer (approximately 0.70 mm). All SiGe layers contained 25% germanium by mass. The Si layers consisted of crystalline Si.

[0125] The following substrates were used in Examples 4 and 5: SALSA III from IMEC. These substrates contain multiple stacked SiGe and Si layers. The SALSA III layers are stacked from top to bottom: SiO 2 (50nm)-SiN(50nm)-Si 0.8 Ge 0.2 (10nm)-Si 0.6 Ge 0.4 (15nm)-Si 0.8 Ge 0.2 (10nm)-Si 0.6 Ge 0.4 (7nm)-Si 0.8 Ge 0.2 (10nm)-Si <100> Wafer (approximately 0.70 mm).

[0126] The following materials were used in electronic grade purity: H 2 O 2 (31%) ·NH 4 F ·Aqueous NH 3 Methyltrimethoxysilane Citric acid ·phosphoric acid Acetic acid Surfynol® 104 (available from Evonik) [ka] Surfynol® 465 (available from Evonik, k, l=10) · Surfynol® 485W (available from Evonik, k, l=30). [ka]

[0127] All amounts given for compounds in compositions are absolute amounts in the total mixture, ie, excluding water.

[0128] Preparation of the etching bath: The etching bath temperature was set at 24°C + / - 0.5°C. 3 The pH was adjusted to 6.05 with .

[0129] Optional pre-etching: Prior to etching, the portion of the coupon containing the microstructure was treated with 0.5% HF for 60 seconds.

[0130] etching: After rinsing with ultrapure water (UPW, electronic grade), the coupons were inserted into the etching bath for 60 s. After etching, they were rinsed with UPW and dried with compressed air.

[0131] Example 1 The compositions shown in Table 1a were prepared.

[0132] [Table 1] Etch rates in Å / min were determined by TEM as a function of the lateral etch depth of the top SiGe25 and Si layers. The results are shown in Table 1b and the substrates etched with the compositions according to examples 1.1, 1.2 and 1.3 are shown in Figures 2, 3 and 4, respectively. Figure 6 shows the substrates after treatment under the conditions of example 1.2, without HF pretreatment.

[0133] [Table 2]

[0134] Table 1b and Figures 3 and 4 show that in Experiments 1.2 and 1.3, SiO 2The lateral loss of SiO2 is caused only by the HF pretreatment. x or Si 3 N 4 This shows that there is no loss of

[0135] For comparison, Figure 5 shows the results after HF pretreatment and no further etching. Even though the etch rate of SiGe is low, it is still faster than Si or SiO x In contrast, the overall selectivity of SiGe is significantly improved.

[0136] Example 2 Example 1 was repeated with the composition shown in Table 2a and the results are shown in Table 2b. The etching rate was determined by ellipsometry by comparing the layer thickness before and after etching.

[0137] [Table 3]

[0138] [Table 4]

[0139] Example 3 Example 1 was repeated with the composition shown in Table 3a and the results are shown in Table 3b. The etching rate was determined by ellipsometry by comparing the layer thickness before and after etching.

[0140] [Table 5]

[0141] [Table 6]

[0142] Comparing Example 3.2 and Comparative Example 3.1, the addition of methyltrimethoxysilane increased the amount of Si, SiO x It can be seen that the etching rate of SiN is reduced by more than one order of magnitude, while the etching rate of SiGe is reduced only slightly. x and leads to a strong selectivity of SiGe etching relative to SiN.

[0143] Example 4 7% NH 4 F, 2.8% H 2 O 2 , 1.0% acetic acid, 0.17% NH 3 A composition containing 0.3% methyltrimethoxysilane was prepared and etched at 24° C. as described above. The etch rates of SiGe20, SiGe40, the selectivity of SiGe40 / SiGe20, and the concentration of the selectivity enhancer are shown in Table 4. A substrate etched with the composition according to Example 4 having 50 ppm Surfynol® 104 is shown in FIG.

[0144] [Table 7]

[0145] The alkynols significantly reduce the etch rate of SiGe20, while the etch rate of SiGe40 remains high. As a result, the selectivity is significantly improved. Higher selectivity overall is observed for the polyalkoxylated alkynediols compared to the non-alkylated alkynediols. The results also show that SiGe40 is superior to SiGe20, Si, and SiO 2 , and Si 3 N 4 It has also been shown that it can be selectively removed in the presence of

[0146] Example 5 For Surfynol® 465, 2 O 2 Example 4 was repeated with different concentrations of 0.1% ethanol. The results are shown in Table 5.

[0147] [Table 8]

[0148] Table 5 shows the H 2 O 2 It can be seen that even higher selectivity was observed at lower concentrations of

[0149] Example 6 The compositions shown in Table 6 were prepared.

[0150] [Table 9]

[0151] Composition with H 2 O 2 (31%) in a 90:1 ratio (V / V) to obtain 9.1 mass% NH 4 F and 0.34% H by mass 2 O 2 The concentration of Ge was obtained. Etching experiments were performed on structured wafers containing SiGe layers with various amounts of Ge. The results are shown in Figure 8.

[0152] FIG. 8 shows that SiGe may be selectively etched down to SiGe25 relative to SiGe20.

Claims

1. 1. A composition for selectively etching a first silicon germanium layer having a first germanium content in the presence of a silicon layer or a second silicon germanium layer having a second germanium content, the first germanium content being greater than the second germanium content, the composition comprising: (a) 0.1 to 10% by weight of an oxidizing agent; (b) an etching solution containing 1 to 20% by mass of a fluoride ion source; (c) 0.001 to 3 wt. % of a selectivity enhancer of formula S1; 【Chemistry 1】 (d) 0.001 to 3 wt. % of an additional selectivity enhancer of formula S41; 【Chemistry 2】 or derivatives obtainable by homocondensation of a compound of formula S41 or by cocondensation of a compound of formula S41 with a silane of formula S42 in a mass ratio of 0.1 or more, and 【Chemistry 3】 (e) water; Including, In the formula, R Ｓ１ , X Ｓ -OH and Y Ｓ -(CO)-OH; R Ｓ２ (i) R Ｓ１ , (ii) H, (iii) C １ ~C １０ alkyl, (iv) C １ ~C １０ alkenyl, (v) C １ ~C １０ Alkynyl, and (vi) -X Ｓ１ -(O-C ２ H ３ R Ｓ６ ) ｍ -OR Ｓ６ Selected from: R Ｓ６ is H and C １ ~C ６ alkyl; R Ｓ４１ may be unsubstituted or -NR Ｓ６１ R Ｓ６２ Or -OR Ｓ６１ C may be replaced by １ ~C ６ is alkyl; R Ｓ４２ , R Ｓ４３ is independently １ ~C ６ Alkoxy and C １ ~C ６ alkyl, any of which may be unsubstituted, or —NR Ｓ６１ R Ｓ６２ Or -OR Ｓ６１ may be substituted with; R Ｓ５１ , R Ｓ５２ may independently be unsubstituted or -NR Ｓ６１ R Ｓ６２ Or -OR Ｓ６１ C may be replaced by １ ~C ６ alkyl; R Ｓ６１ , R Ｓ６２ are independently H and C １ ~C ６ alkyl; X Ｓ is a linear or branched C １ ~C １０ Alkanediyl, linear or branched C ２ ~C １０ Alkenyl, linear or branched C ２ ~C １０ Alkynediyl, and -X Ｓ１ -(O-C ２ H ３ R Ｓ６ ) ｍ - selected from; Y Ｓ is a chemical bond and X Ｓ Selected from: X Ｓ１ is C １ ~C ８ alkanediyl; The composition, wherein m is an integer from 1 to 30.

2. The composition according to claim 1, wherein the oxidizing agent is selected from peroxides, preferably hydrogen peroxide.

3. 3. The composition according to claim 1 or 2, wherein the etching solution is selected from hydrogen fluoride, ammonium fluoride, ammonium difluoride, triethanolammonium fluoride, diglycolammonium fluoride, methyldiethanolammonium fluoride, tetramethylammonium fluoride, triethylamine trihydrofluoride, fluoroboric acid, tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic acid, ammonium fluorosilicate, tetrabutylammonium tetrafluoroborate and mixtures thereof, preferably hydrogen fluoride.

4. The selectivity enhancer is (a) R Ｓ１ Is X Ｓ When it is —OH, it is 0.0005 to 0.02% by weight, preferably 0.001 to 0.005% by weight; or (b) R Ｓ１ Is Y Ｓ When it is —(CO)—OH, it is 0.1 to 3 mass %, preferably 0.5 to 2 mass %. The composition of claim 1 or 2, wherein

5. R Ｓ１ Is X Ｓ -OH, X Ｓ But, C １ ~C ８ Alkanediyl, preferably C １ ~C ６ The composition according to claim 1 or 2, which is an alkane-1,1-diyl.

6. The selectivity enhancer is a compound of formula S2 【Chemistry 4】 (In the formula, R Ｓ１１ , R Ｓ２１ is independently １ ~C ６ selected from alkyl, preferably from ethyl, propyl, butyl, pentyl and hexyl; R Ｓ１２ , R Ｓ２２ are independently H and C １ ~C １０ 6. The composition according to claim 5, wherein the alkyl group is selected from the group consisting of alkyl, preferably H, methyl or ethyl.

7. R Ｓ１ Is X Ｓ -OH, X Ｓ -X Ｓ１ -(O-C ２ H ３ R Ｓ６ ) ｍ - and X Ｓ１ C １ ~C ８ The composition of claim 1 or 2, which is an alkanediyl.

8. The selectivity enhancer is a compound of formula S5 【Chemistry 5】 (In the formula, R Ｓ１１ , R Ｓ２１ is independently １ ~C ６ selected from alkyl, preferably from ethyl, propyl, butyl, pentyl and hexyl; R Ｓ１２ , R Ｓ２２ are independently H and C １ ~C １０ alkyl, preferably selected from H, methyl or ethyl, The composition according to claim 7, wherein k and l are independently integers selected from 1 to 30.

9. The first selectivity enhancer is a compound of formula S3, 【Chemistry 6】 3. The composition of claim 1 or 2, wherein when the first selectivity enhancer is a compound of formula S2, the composition further comprises a second acetylenic compound of formula S3.

10. R Ｓ３１ , R Ｓ３２ , R Ｓ３３ is independently selected from methyl, ethyl, propyl, and butyl; R Ｓ３４ , R Ｓ３５ , R Ｓ３６ is independently H or selected from methyl, ethyl, propyl, and butyl; X Ｓ３１ methanediyl, ethanediyl, propanediyl, butanediyl, and -X Ｓ１ -(O-C ２ H ３ R Ｓ６ ) ｍ - selected from; R Ｓ６ is H or selected from methyl and ethyl; X Ｓ１ is methanediyl, ethanediyl, propanediyl, butanediyl; The composition according to claim 1 or 2, wherein m is an integer from 1 to 6.

11. R Ｓ３１ , R Ｓ３２ , R Ｓ３３ is independently selected from methyl and ethyl; R Ｓ３４ , R Ｓ３５ , R Ｓ３６ is independently H or methyl; X Ｓ３１ is methanediyl, ethane-1,2-diyl, propane-1,3-diyl, or butane-1,4-diyl; X Ｓ１ is methanediyl, ethane-1,2-diyl, propane-1,3-diyl, or butane-1,4-diyl; The composition according to claim 1 or 2, wherein m is an integer from 1 to 6.

12. R Ｓ４１ But, C １ ~C ４ alkyl, preferably methyl, ethyl or propyl; R Ｓ４２ But, C １ ~C ４ Alkyl, preferably methyl, ethyl or propyl, or C １ ~C ４ Alkoxy, preferably methoxy, ethoxy or propoxy; R Ｓ５１ , R Ｓ５２ But independently, C １ ~C ４ 3. The composition according to claim 1 or 2, wherein the alkyl is methyl, ethyl or propyl.

13. The second selectivity enhancer is a compound of formula S49 【Chemistry 7】 (In the formula, R Ｓ５１ , R Ｓ５２ , R Ｓ５３ is independently selected from methyl, ethyl, propyl, or butyl; R Ｓ４１ The composition of claim 1 or 2, wherein: (a) is selected from methyl, ethyl, propyl, or butyl.

14. The composition of claim 1 or 2, wherein the additional selectivity enhancer is present in an amount of from 0.005 to 2 wt %, preferably from 0.05 to 1 wt %.

15. The composition according to claim 1 or 2, wherein the concentration of the oxidizing agent is between 1 and 10% by weight, preferably between 5 and 10% by weight, for etching the first silicon germanium layer in the presence of a silicon layer.

16. The composition according to claim 1 or 2, wherein the concentration of the oxidizing agent is 0.2 to 5 wt. % for etching the first silicon germanium layer in the presence of the second silicon germanium layer.

17. 3. A method of using the composition according to claim 1 or 2 for selectively etching a first silicon germanium layer having a first germanium content in the presence of a silicon layer or a second silicon germanium layer having a second germanium content and optionally a silicon oxide layer, wherein the first germanium content is higher than the second germanium content.

18. 1. A method for selectively removing a first silicon germanium alloy layer having a first germanium content relative to a silicon layer or a second silicon germanium layer having a second germanium content and optionally a silicon oxide layer from a surface of a microelectronic device, the first germanium content being greater than the second germanium content, the method comprising: (a) providing a microelectronic device surface comprising a layer comprising a silicon germanium alloy, a silicon layer, and optionally a silicon oxide layer; (b) providing a composition according to claim 1 or 2; and (c) contacting the surface with the composition for a time and at a temperature effective to selectively remove the silicon-germanium comprising layer relative to the layer comprising or consisting of Si, and optionally the silicon oxide layer. A method comprising:

19. 20. A method for manufacturing a semiconductor device comprising the method of claim 18, wherein a first silicon germanium alloy layer having a first germanium content is selectively removed from the surface relative to a silicon layer or a second silicon germanium layer having a second germanium content and optionally a silicon oxide layer.

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