EP0350997A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Reactive ion etching of a silicon-bearing material with hydrobromic acid
Assignee: Koninklijke Philips NV
•
Filing: 1989-07-05
•
Granted: —
•
Expires: 2009-07-05
Abstract
Abstract A plasma etching process using HBr is set forth in which etching of silicon, polysilicon and silicides in IC manufacture is significantly improved by the high etching selectivity for either silicon and polysilicon to both oxides and photoresist materials.
Inventors
- 👤 Len-Yuan Tsou
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 18:13
CPC Classifications
H; H10; H10P; H10P95/00; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
71 words
A method of manufacturing semiconductors by selectively etching a layer of a silicon-bearing material, comprising the steps of: providing a patterned mask over a layer of silicon-bearing material to expose only areas to be etched, removing any surface oxides from said silicon-bearing layer with an oxide etching plasma, and then exposing said silicon-bearing layer to a hydrogen bromide plasma to selectively etch said silicon-bearing layer relative to photoresist and silicon oxide.
Claim 2
Independent Claim
71 words
A method of manufacturing semiconductors by selectively etching a layer of a silicon-bearing material, comprising the steps of: providing a patterned mask over a layer of silicon-bearing material to expose only areas to be etched, removing any surface oxides from said silicon-bearing layer with an oxide etching plasma, and then exposing said silicon-bearing layer to a hydrogen bromide plasma to selectively etch said silicon-bearing layer relative to photoresist and silicon oxide.
Claim 3
Dependent Claim
23 words
A method according to Claim 1, wherein said silicon-bearing material is one of silicon, doped or undoped polysilicon, tantalum silicide, or titanium silicide.
Claim 4
Dependent Claim
19 words
A method according to Claim 1, wheerein said hydrogen bromide plasma is HBr gas mixed with an inert gas.
Claim 5
Dependent Claim
17 words
A method according to Claim 3, wherein said inert gas is one of He, Ar, or N₂.
Claim 6
Dependent Claim
20 words
A method according to Claim 1, wherein said oxide etching plasma is one of freon, silicon tetrachloride, or boron trichloride.
Claim 7
Dependent Claim
95 words
In a method of manufacturing semiconductor IC devices by etching comprising the steps of (a) forming a composite structure by (i) providing a silicon substrate, (ii) forming a thin layer of oxide on said silicon substrate, (iii) forming a polysilicon layer on said oxide, (iv) forming photoresist on at least parts of said polysilicon layer. (b) removing any surface oxides from said polysilicon layer with an oxide etching plasma, and (c) then exposing the composite structure to a hydrogen bromide plasma to selectively etch said polysilicon layer relative to said photoresist and said silicon oxide.
Claim 8
Dependent Claim
95 words
In a method of manufacturing semiconductor IC devices by etching comprising the steps of (a) forming a composite structure by (i) providing a silicon substrate, (ii) forming a thin layer of oxide on said silicon substrate, (iii) forming a polysilicon layer on said oxide, (iv) forming photoresist on at least parts of said polysilicon layer. (b) removing any surface oxides from said polysilicon layer with an oxide etching plasma, and (c) then exposing the composite structure to a hydrogen bromide plasma to selectively etch said polysilicon layer relative to said photoresist and said silicon oxide.
Claim 9
Dependent Claim
19 words
A method according to Claim 6, wherein said hydrogen bromide plasma is HBr gas mixed with an inert gas.
Claim 10
Dependent Claim
17 words
A method according to Claim 7, wherein said inert gas is one of He, Ar, or N₂.
Claim 11
Dependent Claim
20 words
A method according to Claim 6, wherein said oxide etching plasma is one of freon, silicon tetrachloride or boron trichloride.
Claim 12
Dependent Claim
14 words
A method according to Claim 6, wherein said polysilicon layer is doped or undoped.
Claim 13
Dependent Claim
93 words
A method according to Claim 6, further comprising after said steps (b) and (c) the steps of removing said photoresist from said composite structure, forming at least a second polysilicon layer on said composite structure, forming at least a second photoresist on at least parts of said second polysilicon layer, removing any surface oxides from said second polysilicon layer with said oxide etching plasma, and then exposing said second polysilicon layer to said hydrogen bromide plasma, wherein said second polysilicon layer is selectively etched relative to said second photoresist and said silicon oxide.
Claim 14
Dependent Claim
19 words
A method according to Claim 11, wherein said hydrogen bromide plasma is HBr gas mixed with an inert gas.
Claim 15
Dependent Claim
17 words
A method according to Claim 12, wherein said inert gas is one of He, Ar, or N₂.
Claim 16
Dependent Claim
20 words
A method according to Claim 11, wherein said oxide etching plasma is one of freon, silicon tetrachloride or boron trichloride.
Claim 17
Dependent Claim
14 words
A method according to Claim 11, wherein said polysilicon layer is doped or undoped.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.