Patent US5619044A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5619044A Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor device formed with seed crystals on a layer thereof

Assignee: Sharp Corp
•
Filing: 1995-04-14
•
Granted: 1997-04-08
•
Expires: 2015-04-14
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract According to the present invention, a semiconductor device and a method for producing a semiconductor device in which an active region made of a crystalline silicon film is formed on an insulating surface of a substrate is provided. The method includes the steps of: forming a first amorphous silicon film on the substrate; selectively introducing at least one kind of catalyst elements for promoting the crystallization of the first amorphous silicon film into a part of the first amorphous silicon film before or after forming the first amorphous silicon film; heating the first amorphous silicon film so as to crystallize the first amorphous silicon film in a direction substantially parallel to a surface of the substrate with respect to a region surrounding a region into which the catalyst elements are selectively introduced; forming an insulating thin film in a region on the crystalline silicon film in which crystals are grown in a direction substantially parallel to the surface of the substrate so as to partially remove the insulating thin film and the crystalline silicon film so that a linear boundary is formed along a crystal-growing direction of the crystalline silicon film; forming a second amorphous silicon film on the crystalline silicon film; and crystallizing the second amorphous silicon film by heating or by irradiating a laser beam or an intense light.

Inventors

  • 👤 Naoki Makita
  • 👤 Yoshitaka Yamamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 15:14
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/67; H10P; H10P14/00; H10P14/20; H10P14/38; H10P14/3802; H10P14/3808; H10P14/3816; H10D30/674; H10D30/6741; H10D30/6743; H10D30/6744; H10D86/00; H10D86/01; H10D86/021; H10D86/0221; H10D86/0223; H10D86/0225; H10P14/29; H10P14/2901; H10P14/2922; H10P14/34; H10P14/3402; H10P14/3404; H10P14/3411; H10P14/3806; G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/1333; G02F1/1345; G02F1/13454; H10D30/6729; H10D30/6737; H10D30/6739

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 122 words
A semiconductor device comprising an active region made of a crystalline silicon film on an insulating surface of a substrate, wherein the active region is formed by introducing at least one kind of catalyst elements for promoting a crystallization into a first amorphous silicon film; heating the first amorphous silicon film so as to grow needle-like or column-like crystals; and crystallizing a second amorphous silicon film using the needle-like or column-like crystals as seed crystals that are removed after the second amorphous silicon film has crystallized; wherein the first and second films crystallize to substantially the same extent such that the first film has a column-like structure and a grain boundary exists, and the second film has an almost single crystalline structure.
Claim 2
Dependent Claim 122 words
A semiconductor device comprising an active region made of a crystalline silicon film on an insulating surface of a substrate, wherein the active region is formed by introducing at least one kind of catalyst elements for promoting a crystallization into a first amorphous silicon film; heating the first amorphous silicon film so as to grow needle-like or column-like crystals; and crystallizing a second amorphous silicon film using the needle-like or column-like crystals as seed crystals that are removed after the second amorphous silicon film has crystallized; wherein the first and second films crystallize to substantially the same extent such that the first film has a column-like structure and a grain boundary exists, and the second film has an almost single crystalline structure.
Claim 3
Dependent Claim 26 words
A semiconductor device according to claim 1, wherein a thickness of the needle-like or column-like crystals used as the seed crystals is 100 nm or less.
Claim 4
Dependent Claim 24 words
A semiconductor device according to claim 1, wherein the second amorphous silicon film is crystallized by irradiating a laser beam or an intense light.
Claim 5
Dependent Claim 36 words
A semiconductor device according to claim 1, wherein at least one kind of catalyst elements are selected from a group consisting of Ni, Co, Pd, Pt, Cu, Ag, Au, In, Sn, Al, P, As and Sb.
Claim 6
Dependent Claim 40 words
A semiconductor device according to claim 1, wherein the substrate is made of glass having a distortion point of 700° C. or less, and a crystallinity of the active region is substantially equal to a crystallinity of a single crystal.
Claim 7
Dependent Claim 34 words
A semiconductor device according to claim 5 further comprising a central processing unit formed on the substrate, the central processing unit comprising a thin-film transistor including at least a part of the active region.
Claim 8
Dependent Claim 19 words
A semiconductor device according to claim 5, wherein the distortion point of the glass is 650° C. or less.
Claim 9
Dependent Claim 26 words
A semiconductor device according to claim 5, wherein the active region has a field-effect mobility of 200 cm 2 /Vs or more with respect to electrons.
Claim 10
Dependent Claim 26 words
A semiconductor device according to claim 5, wherein the active region has a field-effect mobility of 150 cm 2 /Vs or more with respect to holes.

References Cited (Backward Citations)

US5318919A Cited
US5442198A Cited
US5403772A Cited
JPH06244103A Cited
JPH06244104A Cited
US5481121A Cited
US5486237A Cited
JPH0758338A Cited
US5468974A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-04-07 2000-10-07 2001-04-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-04-07 2004-10-07 2005-04-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-04-07 2008-10-07 2009-04-08 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag