# US 12,600,909 B2 · Etching solution composition

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,600,909 B2
- Document ID: US12600909B2
- Status: Granted
- Kind: B2
- Application number: 18/569,249
- Filed: 2022-03-30
- Published: 2024-08-22
- Granted: 2026-04-14
- Earliest claimed: 2021-06-14
- Assignees: Rasa Industries, Ltd.
- Applicants: Rasa Industries, Ltd.
- Inventors: Sho Nagao; Tomohiro Inoue; Takao Mitsui; Nobuhiro Oshita; Reiji Uchida
- Web page: https://patentgrep.com/patent/US12600909B2

## CPC

- C09K 13/06: with organic material
- C09K 13/00: Etching, surface-brightening or pickling compositions (for glass C03C15/00, {C03C25/66; for mortars, concrete, artificial or natural stone or ceramics C04B41/5338}; for metallic material C23F, C23G1/00, C25F1/00; {for semi-conductors H10P52/40})
- C09K 13/04: containing an inorganic acid
- H10P 50/00: Etching of wafers, substrates or parts of devices
- H10P 50/28: of insulating materials
- H10P 50/282: {of inorganic materials}
- H10P 50/283: {by chemical means}
- H10P 50/642: {Chemical etching}
- H10P 50/667: {by liquid etching only}
- H10P 50/691: {for Group IV materials or Group III-V materials}
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

Provided is an etching solution composition that can have both a higher etch selectivity of silicon nitride and a reduction in the deposition of silica on the surface of silicon oxide. An inorganic acid-based etching solution composition for selectively etching away silicon nitride from a semiconductor containing silicon nitride and silicon oxide, the etching solution composition comprising: (a) an etch inhibitor that reduces etching of silicon oxide; and (b) a deposition inhibitor that reduces deposition of silica on a surface of silicon oxide.

## Claims

### Claim 1

An inorganic acid-based etching solution composition for selectively etching away silicon nitride from a semiconductor containing silicon nitride and silicon oxide, the etching solution composition comprising:
(a) an etch inhibitor that reduces etching of silicon oxide; and
(b) a deposition inhibitor that reduces deposition of silica on a surface of silicon oxide, wherein
the etch inhibitor contains an alkoxysilane or a silane coupling agent, and
the deposition inhibitor contains a hydrazide.

### Claim 2 (depends on 1)

The etching solution composition according to claim 1, wherein
the alkoxysilane includes dimethyldimethoxysilane, and
the silane coupling agent includes N-2-(aminoethyl)-3-aminopropyltrimethoxysilane or 3-aminopropyltrimethoxysilane.

### Claim 3 (depends on 1)

The etching solution composition according to claim 1, wherein
the hydrazide includes adipic acid dihydrazide, acetohydrazide, succinic acid dihydrazide, or dodecanedioic acid dihydrazide.

### Claim 4 (depends on 1)

The etching solution composition according to claim 1, wherein
the deposition inhibitor further includes a compound having an imidazole backbone, a compound having a pyrrolidine backbone, a phosphonic acid compound, or a compound having a quaternary ammonium backbone.

### Claim 5 (depends on 4)

The etching solution composition according to claim 4, wherein
the compound having an imidazole backbone includes imidazole, 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium hexafluorophosphate, or 1-ethyl-3-octylimidazolium tetrafluoroborate,
the compound having a pyrrolidine backbone includes 1-butyl-1-methylpyrrolidinium hexafluorophosphate or 1-butyl-1-methylpyrrolidinium tetrafluoroborate,
the phosphonic acid compound includes tetrabutylphosphonium bromide, and
the compound having a quaternary ammonium backbone includes tetramethylammonium hexafluorophosphate.

### Claim 6 (depends on 1)

The etching solution composition according to claim 1, wherein
the etching solution composition can be used until the concentration of Si derived from silicon nitride in the solution reaches 1000 ppm.

### Claim 7 (depends on 1)

The etching solution composition according to claim 1, wherein
a selectivity ratio [R1/R2] of a silicon nitride etch rate [R1] to a silicon oxide etch rate [R2] is at least two times as high as that of an etching solution containing only the inorganic acid.