EP0726600A2
Expired / Lapsed
EP
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Method of forming a structure for DRAM and structure formed thereby
Assignee: Texas Instruments Inc
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Filing: 1996-02-13
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Granted: —
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Expires: 2016-02-13
Abstract
Abstract Generally, the present invention utilizes dry plasma etching techniques such as Electron Cyclotron Resonance (ECR) to produce sloped sidewalls on a DRAM storage cell. The rounded corners of the lower electrode made by this technique allow the advanced dielectric material to be deposited without substantial cracking, and it also allows the capacitance to be closely predicted and controlled due to the uniformity in which the advanced dielectric layer can be fabricated. One embodiment of the present invention is method of making a microelectronic structure comprising a supporting layer (e.g. Si substrate 30) having a principal surface, a lower electrode overlying the principal surface of the supporting layer, and a high-dielectric-constant material layer (e.g. BST 44) overlying the top surface of the lower electrode. The lower electrode comprises a barrier layer (e.g TiN 36), and an unreactive layer (e.g. Pt 42).
Inventors
- 👤 Robert Yung-Hsi Tsu
- 👤 Wei-Yung Hsu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 16:11
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/267; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10D; H10D1/00; H10D1/60; H10D1/68; Y; Y10; Y10S; Y10S438/00; Y10S438/978
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
98 words
A method of forming a microelectronic structure, said method comprising steps: forming a conductive barrier layer on a principal surface of a microelectronic substrate where said conductive barrier layer comprises a lateral surface and an upper surface forming a corner edge; forming an unreactive layer on said barrier layer, patterning photoresist on the uppermost of said layers, etching said uppermost layer by dry plasma etch with at least partial horizontal etching to form sloped lateral sides on said unreactive layer, overlying said corner edge on said barrier layer; and depositing a high-dielectric-constant material layer on said unreactive layer.
Claim 2
Dependent Claim
25 words
The method according to claim 1, wherein said sloped lateral sides are formed at an angle of less than 80 degrees from the substrate surface.
Claim 3
Dependent Claim
21 words
The method according to claim 1, wherein said sloped lateral sides are formed at an angle of less than 75 degrees.
Claim 4
Dependent Claim
28 words
The method of claim 1 or claim 2 and wherein said sloped lateral sides are formed at an angle of greater than 40 degrees from the substrate surface.
Claim 5
Independent Claim
20 words
The method according to any preceding claim wherein said dry plasma process is an Electron Cyclotron Resonance plasma etch process.
Claim 6
Independent Claim
78 words
The method according to any preceding claim further comprising forming said barrier layer from material selected from the group of materials consisting of: conductive metals, conductive metal nitrides, conductive metal oxides, conductive metal silicides, conductive metal carbides, conductive metal borides, ternary amorphous nitrides, titanium aluminum nitride, Zr nitride, Hf nitride, Y nitride, Sc nitride, La nitride, N deficient Al nitride, doped Al nitride, Mg nitride, Ca nitride, Sr nitride, Ba nitride, TaSi nitride, TiSi nitride, and combinations thereof.
Claim 7
Independent Claim
80 words
The method according to any preceding claim further comprising forming said unreactive layer from a material selected from the group of materials consisting of: platinum, palladium, iridium, rhenium, rhodium, gold, silver, ruthenium oxide, tin oxide, titanium monoxide, indium oxide, rhenium oxide, osmium oxide, rhodium oxide, iridium oxide, doped tin oxide, doped indium oxide, doped zinc oxide, ruthenium nitride, tin nitride, titanium nitride, Zirconium nitride, YBa 2 Cu 3 O 7-x , (La,Sr)CoO 3 , SrRuO 3 , and combinations thereof.
Claim 8
Independent Claim
58 words
The method according to any preceding claim further comrpising forming said high-dielectric-constant material layer from a material selected from the group of materials consisting of: barium strontium titanate, lead zirconate titanate, lead lanthanum titanate, lead lanthanum zirconate titanate, bismuth titanate, potassium tantalate, lead scandium tantalate, lead niobate, lead zinc niobate, potassium niobate, lead magnesium niobate, and combinations thereof.
Claim 9
Independent Claim
18 words
The method according to any preceding claim, further comprising forming an upper electrode on said high-dielectric-constant material layer.
Claim 10
Dependent Claim
18 words
The method according to claim 9, further comprising forming said upper electrode from a material which comprises platinum.
Claim 11
Independent Claim
22 words
The method according to any preceding claim, said method further comprising forming an unreactive layer with an aspect ratio greater than 1.
Claim 12
Independent Claim
27 words
The method of any preceding claim further comprising forming said unreactive layer after said etch step such that said barrier layer is etched as said uppermost layer.
Claim 13
Dependent Claim
17 words
A micro-electronic structure having the arrangement of the structure formed by the method of any preceding claim.
Claim 14
Dependent Claim
16 words
A micro-electronic structure as claimed in claim 13 and providing a DRAM-cell or a part thereof.
Claim 15
Dependent Claim
13 words
A DRAM including a cell or cell part as claimed in claim 14.
References Cited (Backward Citations)
JPH0730077A
Cited
US5442213A
Cited
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