EP0572943A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
High resolution etching mask
Assignee: International Business Machines Corp
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Filing: 1993-05-28
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Granted: —
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Expires: 2013-05-28
Abstract
Abstract A method is provided to enable the formation of sub-lithographic relief images to increase the surface area of semiconductor structures for use in the capacitors of DRAM cells. The method includes the steps of forming in situ a non-planar region (12) having a relief pattern (14) comprising sub-micron sized elements and the transferring the relief pattern (14) into a masking layer (16) in order to selectively etch a substrate (10) to form relatively deep trenches (20) having a density equal to the relief pattern (14). Polysilicon and porous silicon can be used to form the sub-micron relief pattern.
Inventors
- 👤 Donald Mcalpine Kenney
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:08
CPC Classifications
B; B82; B82Y; B82Y10/00; H; H10; H10P; H10P76/00; H10P76/40; H10P76/408; H10P76/4085; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10B12/30; H10B12/31; H10B12/318; H10D; H10D1/00; H10D1/01; H10D1/041; H10D1/043; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/716; Y; Y10; Y10S; Y10S438/00; Y10S438/964; Y10S977/00; Y10S977/70; Y10S977/778; Y10S977/78; Y10S977/784; Y10S977/84; Y10S977/887
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
91 words
The method of forming regular sub-lithographic patterns in the range of tens to hundreds of nm units in dimension comprising the steps of: forming on the surface of a substrate (10) a non-planar region (12) including a relief pattern (14) having dimensions on the order of one to several tens of nm units; selectively forming a masking pattern (18) using said relief pattern (14) to determine the configuration thereof; and using the selectively formed masking pattern (18) to enable the selective etching of substantially vertical trench-like regions into said substrate (10).
Claim 2
Dependent Claim
62 words
The method of claim 1 wherein the step of selectively forming the masking pattern (18) includes the step of depositing a layer (16) of selectively etchable material over the relief pattern formed on the substrate (10); and the sub-step of selectively removing portions of the thickness said selectively etchable material to expose at least the upper portion of said relief pattern (14).
Claim 3
Dependent Claim
13 words
The method of claim 2 wherein the selectively etchable material comprises an oxide.
Claim 4
Dependent Claim
15 words
The method of claim 2 or 3 wherein the selectively etchable material is silicon dioxide.
Claim 5
Independent Claim
46 words
The method of any of the preceding claims 1 to 4 wherein the step of selectively forming the masking pattern (18) includes the step of forming a masking layer (16) on the surface of the substrate (10) prior to the formation of the non-planar region (12).
Claim 6
Independent Claim
34 words
The method of any of the preceding claims 1 to 5 wherein the formation of the non-planar region (12) includes the deposition of polycrystalline silicon under conditions which produce sub-lithographic and sub-micron relief patterns.
Claim 7
Dependent Claim
17 words
The method of claim 6 wherein the deposition proceeds at a temperature between 550 and 570 °C.
Claim 8
Independent Claim
16 words
The method of any of the preceding claims 1 to 7 wherein the substrate is silicon.
Claim 9
Independent Claim
25 words
The method of any of the preceding claims 6 to 8 wherein the sub-lithographic relief patterns are formed of polysilicon formed in hemispherical grain structures.
Claim 10
Independent Claim
24 words
The method of any of the preceding claims 1 to 9 wherein the non-planar region (12) is at least partially formed of porous silicon.
References Cited (Backward Citations)
DE4222584A1
Cited
GB2259406A
Cited
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