Dry etching methods

Claim 2

A composite gas for dry etching to form a desired configuration of trench (14) in monocrystalline silicon, the gas being composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas and containing at least ClF₃ for forming a protective layer (15) on the side wall of said trench (14).

Claim 3

A composite gas according to claim 1 wherein said base composite gas is SiCl₄./N₂ type gas, Cl₂/N₂ type gas, Cl₂/O₂ type gas, Br₂/N₂ type gas, HBr/N₂ type gas or SiCl₄/O₂ type gas.

Claim 4

A composite gas according to claim 1 or claim 2 wherein said additive gas is added to the base composite gas in a range of 1 to 90%.

Claim 5

A composite gas for dry etching to forming a desired configuration of trench (14) in monocrystalline silicon, the gas being composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas, and containing at least Si and F as components.

Claim 6

A composite gas for dry etching to forming a desired configuration of trench (14) in monocrystalline silicon, the gas being composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas, and containing at least Si and F as components.

Claim 7

A composite gas according to claim in wherein said base composite gas is SiCl₄/N₂ type gas or Br₂/N₂ type gas.

Claim 8

A composite gas according to claim in or claim 5 wherein said additive gas is SiF₄ gas.

Claim 9

A dry etching process for forming a trench (14) in monocrystalline silicon, the process comprising the steps of: forming an opening (11a) in an SiO₂ layer (11) formed on a monocrystalline silicon substrate (10); performing etching utilizing the residual SiO₂ layer (11) as a masking layer and with an etching gas, which is composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas, said additive gas containing at least ClF₃ for forming a protective layer (15) on the side wall of said trench (14).

Claim 10

A dry etching process for forming a trench (14) in monocrystalline silicon, the process comprising the steps of: forming an opening (11a) in an SiO₂ layer (11) formed on a monocrystalline silicon substrate (10); performing etching utilizing the residual SiO₂ layer (11) as a masking layer and with an etching gas, which is composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas, said additive gas containing at least ClF₃ for forming a protective layer (15) on the side wall of said trench (14).

Claim 11

A process according to claim 7 wherein said base composite gas is SiCl₄/N₂ type gas, Cl₂/N₂ type gas, Cl₂/O₂ type gas, Br₂/N₂ type gas, HBr/N₂ type gas or SiCl₄/O₂ type gas.

Claim 12

A process according to claim 7 wherein said additive gas is added to the base composite gas in a range of 1 to 90%.

Claim 13

A dry etching process for forming a trench (14) in monocrystalline silicon, the process comprising the steps of: forming an opening (11a) in an SiO₂ layer (11) formed on a monocrystalline silicon substrate (10); performing etching utilizing the residual SiO₂ layer (11) as a masking layer and with an etching gas, which is composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas, said additive gas being containing at least Si and F as components.

Claim 14

A dry etching process for forming a trench (14) in monocrystalline silicon, the process comprising the steps of: forming an opening (11a) in an SiO₂ layer (11) formed on a monocrystalline silicon substrate (10); performing etching utilizing the residual SiO₂ layer (11) as a masking layer and with an etching gas, which is composed of: a base composite gas for etching the monocrystalline silicon; and an additive gas added to said base composite gas, said additive gas being containing at least Si and F as components.

Claim 15

A process according to claim 10 wherein said base composite gas is SiCl₄/N₂ type gas or Br₂/N₂ type gas.

Claim 16

A process according to claim 10 wherein said additive gas is SiF₄ gas.