EP0697718A1
Expired / Lapsed
EP
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Method of making electrical connections to materials with high dielectric constant
Assignee: Texas Instruments Inc
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Filing: 1995-07-25
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Granted: —
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Expires: 2015-07-25
Abstract
Abstract An improved method of forming a capacitor electrode for a microelectronic structure such as a dynamic read only memory is disclosed which has a high dielectric constant (HDC) material as a capacitor dielectric. According to an embodiment of the present invention, shown in Figure 4, the sidewall of the adhesion layer (e.g. TiN 36 ) in a lower electrode is pre-oxidized after deposition of an unreactive noble metal layer (e.g. Pt 38 ) but before deposition of an HDC material (e.g. BST 42 ). An important aspect of the present invention is that the pre-oxidation of the sidewall generally causes a substantial amount of the potential sidewall expansion (and consequent noble metal layer deformation) to occur before deposition of the HDC material.
Inventors
- 👤 Yasushiro Nishioka
- 👤 Scott R. Summerfelt
- 👤 Kyung-Ho Park
- 👤 Pijush Bhattacharya
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 12:06
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/682; H10D1/696; Y; Y10; Y10S; Y10S257/00; Y10S257/915
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
101 words
A method of forming a microelectronic structure, said method comprising steps: (a) forming a supporting layer having a principal surface; (b) forming an adhesion layer on the principal surface, the adhesion layer comprising a substantially unoxidized sidewall; (c) forming a conductive layer on a top surface of the adhesion layer; (d) oxidizing the unoxidized sidewall to form a pre-oxidized sidewall; and (e) depositing a high-dielectric-constant material layer on the conductive layer, wherein the pre-oxidized sidewall inhibits further oxidation and expansion of the adhesion layer adjacent the pre-oxidized sidewall, whereby expansion stress and cracking of the high-dielectric-constant material layer is substantially prohibited.
Claim 2
Dependent Claim
25 words
The method according to Claim 1, wherein the step of forming the pre-oxidized sidewall deforms a portion of the conductive layer overlying the pre-oxidized sidewall.
Claim 3
Independent Claim
23 words
The method according to Claims 1 - 2, further comprising depositing the high-dielectric-constant material layer on the pre-oxidized sidewall of the adhesion layer.
Claim 4
Independent Claim
17 words
The method according to Claims 1 - 3, further comprising forming conductive oxide on the pre-oxidized sidewall.
Claim 5
Dependent Claim
26 words
The method according to Claim 4, further comprising forming the adhesion layer such that the adhesion layer comprises ruthenium and said pre-oxidized sidewall comprises ruthenium dioxide.
Claim 6
Independent Claim
33 words
The method according to Claims 1 - 5, said method further comprising oxidizing the top surface of the adhesion layer prior to the step of forming the conductive layer on the top surface.
Claim 7
Independent Claim
29 words
The method according to Claims 1 - 6, said method further comprising oxidizing said top surface of said adhesion layer during said step of depositing the high-dielectric-constant material layer.
Claim 8
Independent Claim
19 words
The method according to Claims 1 - 7, further comprising forming an upper electrode on said high-dielectric-constant material layer.
Claim 9
Dependent Claim
28 words
The method according to Claim 8, comprising forming said upper electrode from a material selected from the group containing: palladium, ruthenium, rhodium, gold, iridium, silver, and combinations thereof.
Claim 10
Independent Claim
23 words
The method according to Claims 1 - 9, further comprising oxidizing the pre-oxidized sidewall such that the pre-oxidized sidewall comprises an insulating oxide.
Claim 11
Independent Claim
29 words
The method according to Claims 1 - 10, further comprising forming the adhesion layer such that the adhesion layer comprises titanium nitride and said insulating oxide comprises titanium dioxide.
Claim 12
Independent Claim
39 words
The method according to Claims 1 - 11, further comprising forming the adhesion layer from a material selected from the group containing: metals, metal nitrides, metal oxides, metal silicides, metal carbides, metal borides, ternary amorphous nitrides, and combinations thereof.
Claim 13
Independent Claim
51 words
The method according to Claims 1 - 12, further comprising forming the adhesion layer from the group of materials containing: 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, and combinations thereof.
Claim 14
Independent Claim
55 words
The method according to Claims 1 - 13, further comprising the high-dielectric-constant material layer from a material selected from the group containing: 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 15
Dependent Claim
29 words
The method according to Claim 1 - 14, further comprising forming the conductive layer from a material selected from the group containing: platinum, palladium, iridium, rhodium, and combinations thereof.
Claim 16
Independent Claim
20 words
The method of Claims 1 - 15, further comprising forming the adhesion layer such that the adhesion layer is conductive.
Claim 17
Independent Claim
20 words
The method of Claims 1 - 16, further comprising forming the conductive layer from a material comprising a noble metal.
Claim 18
Independent Claim
99 words
A method of forming a microelectronic capacitor according to any preceding claim, said method comprising stops: (a) forming a supporting layer having a principal surface; (b) forming an adhesion layer on said principal surface of said supporting layer; (c) forming a conductive layer on a top surface of the adhesion layer, the adhesion layer comprising a substantially unoxidized sidewall; (d) oxidizing the unoxidized sidewall of the adhesion layer to form a substantially oxidized sidewall; (e) subsequent to oxidizing said sidewall depositing a high-dielectric-constant layer on said conductive layer; and (f) forming an upper electrode on said high-dielectric constant layer.
Claim 19
Dependent Claim
90 words
A microelectronic structure comprising: (a) a supporting layer having a principal surface; (b) an adhesion layer overlying the principal surface of the supporting layer, the adhesion layer comprising a top surface and an expanded, oxidized sidewall; (c) a conductive layer overlying the top surface of the adhesion layer, the conductive comprising a deformed area overlying the oxidized sidewall; and (e) a high-dielectric-constant material layer overlying the conductive layer, whereby the high-dielectric-constant material layer is substantially free of expansion stress cracks in proximity to the deformed area of the conductive layer.
References Cited (Backward Citations)
EP0557937A1
Cited
DE4402216A1
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