# US 2021/0242019 A1 · Tin oxide thin film spacers in semiconductor device manufacturing

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- Number: US 2021/0242019 A1
- Document ID: US20210242019A1
- Status: Published application
- Kind: A1
- Application number: 17/302,044
- Filed: 2021-04-22
- Published: 2021-08-05
- Earliest claimed: 2016-06-28
- Assignees: Lam Research Corporation
- Applicants: Lam Research Corporation
- Inventors: David Charles Smith; Richard Wise; Arpan Pravin Mahorowala; Patrick A. van Cleemput; Bart J. van Schravendijk
- Web page: https://patentgrep.com/patent/US20210242019A1

## CPC

- H10P 76/405: {characterised by their composition, e.g. multilayer masks}
- C23C 16/407: {of zinc, germanium, cadmium, indium, tin, thallium or bismuth}
- C23C 16/45542: {Plasma being used non-continuously during the ALD reactions}
- C23C 16/45553: {characterized by the use of precursors specially adapted for ALD}
- C23C 16/56: After-treatment
- H01J 37/32091: {the radio frequency energy being capacitively coupled to the plasma}
- H10P 14/6336: {in the presence of a plasma [PECVD]}
- H10P 14/6339: {deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD}
- H10P 14/6939: {characterised by the metal}
- H10P 50/268: {of silicon-containing layers}
- H10P 50/283: {by chemical means}
- H10P 50/285: {of materials not containing Si, e.g. PZT or Al2O3}
- H10P 50/71: {using masks for conductive or resistive materials}
- H10P 50/73: {using masks for insulating materials}
- H10P 72/0421: {for drying etching}
- H10P 76/20: of masks comprising organic materials
- H10P 76/4085: {characterised by the processes involved to create the masks}
- H01J 37/32862: {In situ cleaning of vessels and/or internal parts}
- H01J 2237/3321: CVD [Chemical Vapor Deposition]
- H01J 2237/3341: Reactive etching
- H01J 2237/3342: Resist stripping
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

Thin tin oxide films can be used in semiconductor device manufacturing. In one implementation, a method of processing a semiconductor substrate includes: providing a semiconductor substrate having a plurality of protruding features residing on an etch stop layer material, and an exposed tin oxide layer in contact with both the protruding features and the etch stop layer material, where the tin oxide layer covers both sidewalls and horizontal surfaces of the protruding features; and then completely removing the tin oxide layer from horizontal surfaces of the semiconductor substrate without completely removing the tin oxide layer residing at the sidewalls of the protruding features. Next, the protruding features can be removed without completely removing the tin oxide layer that resided at the sidewalls of the protruding features, thereby forming tin oxide spacers.

## Claims

### Claim 1

A method of processing a semiconductor substrate, the method comprising:
(a) providing a semiconductor substrate comprising a plurality of protruding features residing on an etch stop layer material, and an exposed SnO2 layer in contact with both the protruding features and the etch stop layer material, wherein the SnO2 layer covers both sidewalls and horizontal surfaces of the protruding features; and
(b) completely removing the SnO2 layer from horizontal surfaces of the semiconductor substrate without completely removing the SnO2 layer residing at the sidewalls of the protruding features.

### Claim 2 (depends on 1)

The method of claim 1, wherein the etch stop layer material and a material of the protruding features are selected such that a ratio of an etch rate of the etch stop layer material to an etch rate of SnO2 is greater than 1 for a first etch chemistry, and a ratio of an etch rate of the material of the protruding features to an etch rate of SnO2 is greater than 1 for a second etch chemistry.

### Claim 3 (depends on 1)

The method of claim 1, wherein the protruding features comprise amorphous carbon or amorphous silicon.

### Claim 4 (depends on 1)

The method of claim 1, wherein the etch stop layer material comprises a silicon-containing material.

### Claim 5 (depends on 4)

The method of claim 4, wherein the etch stop layer material comprises a silicon-containing compound selected from the group consisting of silicon nitride, silicon oxide and combinations thereof.

### Claim 6 (depends on 4)

The method of claim 4, wherein the etch stop layer material comprises silicon oxide.

### Claim 7 (depends on 4)

The method of claim 4, wherein the etch stop layer material comprises silicon nitride.

### Claim 8 (depends on 1)

The method of claim 1, further comprising:
(c) after (b), completely removing the protruding features, without completely removing the SnO2 layer that resided at the sidewalls of the protruding features, thereby forming a plurality of SnO2 spacers on the etch stop layer material.

### Claim 9 (depends on 8)

The method of claim 8, further comprising etching the etch stop layer material to expose an underlying material in a presence of SnO2 spacers.

### Claim 10 (depends on 1)

The method of claim 1, wherein (b) comprises etching the SnO2 layer using a wet etch chemistry.

### Claim 11 (depends on 1)

The method of claim 1, wherein (b) comprises etching the SnO2 layer using a dry etch chemistry.

### Claim 12 (depends on 1)

The method of claim 1, wherein (b) comprises etching the SnO2 layer using HBr in a plasma.

### Claim 13 (depends on 1)

The method of claim 1, wherein (b) comprises etching the SnO2 layer using H2 in a plasma.

### Claim 14 (depends on 1)

The method of claim 1, wherein (b) comprises etching the SnO2 layer using Cl2 in a plasma.

### Claim 15 (depends on 1)

The method of claim 1, wherein (b) comprises etching the SnO2 layer using different etch chemistries consecutively, wherein a later-used etch chemistry has a higher etch selectivity for SnO2 relative to underlying materials than an earlier-used etch chemistry.

### Claim 16 (depends on 1)

The method of claim 1, further comprising prior to (a): depositing the SnO2 layer, wherein the depositing comprises sequentially exposing the semiconductor substrate to a tin-containing precursor and an oxygen-containing precursor.

### Claim 17 (depends on 16)

The method of claim 16, wherein the tin-containing precursor is an alkyl-substituted tin amide.

### Claim 18 (depends on 16)

The method of claim 16, wherein the tin-containing precursor is selected from the group consisting of tetrakis(dimethylamino)tin, tetrakis(ethylmethylamino)tin, N2, N3-di-tert-butyl-butane-2,3-diamino-tin(II), and 1,3-bis (1,2methylethyl)-4,5-dimethyl-(4R, 5R)-1,3,2-diazastannolidin-2-ylidine.

### Claim 19 (depends on 16)

The method of claim 16, wherein the tin-containing precursor is tetrakis(dimethylamino)tin.

### Claim 20

An apparatus for processing a semiconductor substrate, the apparatus comprising:
(a) a process chamber comprising a semiconductor substrate holder configured for holding the semiconductor substrate during processing, and
(b) a controller comprising program instructions for causing processing of a semiconductor substrate comprising a plurality of protruding features residing on an etch stop layer material, and an exposed SnO2 layer in contact with both the protruding features and the etch stop layer material, wherein the SnO2 layer covers both sidewalls and horizontal surfaces of the protruding features, wherein the program instructions comprise instructions for causing:
(i) complete removal of the SnO2 layer from horizontal surfaces of the semiconductor substrate without complete removal of the SnO2 layer residing at the sidewalls of the protruding features.