US5124767A
Expired / Lapsed
US
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Dynamic random access memory cell with improved stacked capacitor
Assignee: NEC Electronics Corp
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Filing: 1990-05-24
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Granted: 1992-06-23
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Expires: 2010-05-24
Abstract
Abstract A dynamic random access memory cell with a stacked capacitor comprises a switching transistor shifted between on and off states, an inter-level insulating film covering the switching transistor and having a contact window and a storage capacitor provided on the inter-level insulating film and coupled to the switching transistor through the contact window, and the storage capacitor includes a lower electrode having a generally convex top surface and a pug portion penetrating through the contact window so as to electrically connect with the switching transistor, a thin dielectric film covering the generally convex top surface of the lower electrode and an upper electrode formed on the thin dielectric film, since the thin dielectric film extends along the generally convex top surface, a conformal coverage takes place for producing uniform electric field across the thin dielectric film, thereby decreasing undesirable leakage current flowing between the lower and upper electrodes.
Inventors
- 👤 Kuniaki Koyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:14
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/30; H10B12/31
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
A semiconductor device comprising: a semiconductor substrate having an element forming region selectively formed therein: an insulating film covering said semiconductor substrate, a contact hole being formed in said insulating film for exposing a part of said element forming region; a lower electrode having a smooth convex top surface and filling said contact hole so as to be held in contact with said part of said element forming region in an ohmic manner, said smooth convex top surface terminating on a substantially flat surface of said insulating film; a dielectric film covering said smooth convex top surface and extending on said substantially flat surface; and an upper electrode formed on a surface of said dielectric film.
Claim 2
Dependent Claim
116 words
A semiconductor device comprising: a semiconductor substrate having an element forming region selectively formed therein: an insulating film covering said semiconductor substrate, a contact hole being formed in said insulating film for exposing a part of said element forming region; a lower electrode having a smooth convex top surface and filling said contact hole so as to be held in contact with said part of said element forming region in an ohmic manner, said smooth convex top surface terminating on a substantially flat surface of said insulating film; a dielectric film covering said smooth convex top surface and extending on said substantially flat surface; and an upper electrode formed on a surface of said dielectric film.
Claim 3
Dependent Claim
66 words
A semiconductor device as set forth in claim 1, in which said semiconductor device further comprises a switching transistor electrically coupled with said lower electrode and comprising source and drain regions formed in a surface portion of said semiconductor substrate, a gate insulating film covering at least the surface portion between the source and drain regions and a gate electrode formed on said gate insulating film.
Claim 4
Dependent Claim
20 words
The semiconductor device as set forth in claim 1, in which said lower electrode is formed of a doped silicon.
Claim 5
Dependent Claim
36 words
The semiconductor device as set forth in claim 3, in which said thin dielectric film is formed of a substance selected from the group consisting of a silicon nitride, a silicon oxide and a tantalum oxide.
Claim 6
Dependent Claim
20 words
The semiconductor device as set forth in claim 4, in which said upper electrode is formed of a doped polysilicon.
Claim 7
Dependent Claim
21 words
The semiconductor device as set forth in claim 3, in which said doped silicon is of a single crystal epitaxial silicon.
Claim 8
Dependent Claim
18 words
The semiconductor device as set forth in claim 3, in which said doped silicon is of a polysilicon.
Claim 9
Dependent Claim
18 words
The semiconductor device as set forth in claim 1, in which said lower electrode is formed of tungsten.
Claim 10
Dependent Claim
36 words
The semiconductor device as set forth in claim 8, in which said thin dielectric film is formed of a substance selected from the group consisting of a silicon nitride, a silicon oxide and a tantalum oxide.
Claim 11
Dependent Claim
113 words
A semiconductor device comprising: a semiconductor substrate having an element forming region selectively formed therein; an insulating film covering said semiconductor substrate, a contact hole being formed in said insulating film for exposing a part of said element forming region; a silicon electrode grown on said part of said element forming region serving as a seed of growth for filling said contact hole and having a smooth convex top surface, said smooth convex top surface terminating on a substantially flat surface of said insulating film; a dielectric film covering said smooth convex top surface and extending on said substantially flat surface; and an upper electrode formed on a surface of said dielectric film.
Claim 12
Dependent Claim
113 words
A semiconductor device comprising: a semiconductor substrate having an element forming region selectively formed therein; an insulating film covering said semiconductor substrate, a contact hole being formed in said insulating film for exposing a part of said element forming region; a silicon electrode grown on said part of said element forming region serving as a seed of growth for filling said contact hole and having a smooth convex top surface, said smooth convex top surface terminating on a substantially flat surface of said insulating film; a dielectric film covering said smooth convex top surface and extending on said substantially flat surface; and an upper electrode formed on a surface of said dielectric film.
References Cited (Backward Citations)
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