US6100111A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for fabricating a silicon carbide device
Assignee: Wolfspeed Inc
•
Filing: 1998-04-06
•
Granted: 2000-08-08
•
Expires: 2018-04-06
Abstract
Abstract A method of fabricating a semiconductor device on a substrate, wherein the substrate comprises a first layer of doped silicon carbide of a first conducting type and exhibits at least one hollow defect. In a first step the positions of the hollow defects in the substrate are identified, whereafter a second SiC layer of a second conducting type is formed in contact with the first layer, whereafter the first and second layer constituting the pn junction are provided with at least one edge termination surrounding any hollow defect, whereby the defect is excluded from the high-field region of the device.
Inventors
- 👤 Andrei Konstantinov
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:55
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D30/665; H10D12/00; H10D12/01; H10D12/031; H10D12/032; H10D30/01; H10D30/021; H10D30/028; H10D30/0291; H10D62/00; H10D62/80; H10D62/83; H10D62/832; H10D62/8325; H10D8/00; H10D8/01; H10D8/043; H10D8/051; H10D8/411; H10D84/00; H10D84/101; H10D84/141; H10D84/146
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
98 words
A method of fabricating a semiconductor device on a substrate, the substrate comprising a first layer of doped silicon carbide (SiC) of a first conducting type and, having at least one hollow defect said method comprising the steps of: identifying the positions of the hollow defects in the substrate; forming a second SiC layer of a second conducting type in contact with the first layer; and providing the first and second layer constituting the pn junction with at least one edge termination surrounding any hollow defect, whereby the defect is excluded from the high-field region of the device.
Claim 2
Independent Claim
98 words
A method of fabricating a semiconductor device on a substrate, the substrate comprising a first layer of doped silicon carbide (SiC) of a first conducting type and, having at least one hollow defect said method comprising the steps of: identifying the positions of the hollow defects in the substrate; forming a second SiC layer of a second conducting type in contact with the first layer; and providing the first and second layer constituting the pn junction with at least one edge termination surrounding any hollow defect, whereby the defect is excluded from the high-field region of the device.
Claim 3
Independent Claim
95 words
A method of fabricating a semiconductor device on a substrate, the substrate comprising a first layer of doped silicon carbide (SiC) of a first conducting type and exhibits at least one hollow defect, said method comprising the steps of: identifying the positions of the hollow defects in the substrate; forming a metal layer on the first layer excluding areas around the micropipes, in that a Schottky diode is formed; providing the Schottky junction with at least one edge termination surrounding any hollow defect, whereby the defect is excluded from the high-field region of the device.
Claim 4
Independent Claim
95 words
A method of fabricating a semiconductor device on a substrate, the substrate comprising a first layer of doped silicon carbide (SiC) of a first conducting type and exhibits at least one hollow defect, said method comprising the steps of: identifying the positions of the hollow defects in the substrate; forming a metal layer on the first layer excluding areas around the micropipes, in that a Schottky diode is formed; providing the Schottky junction with at least one edge termination surrounding any hollow defect, whereby the defect is excluded from the high-field region of the device.
Claim 5
Dependent Claim
71 words
A method according to claim 1, wherein for forming the pn junction, the first layer, being low doped, is epitaxially grown on a third layer of the first conducting type, the first and third layer forming the substrate, and the second layer, being highly doped, is formed by implanting a dopant into a portion of the first layer, and wherein the areas surrounding the hollow defects are excluded from ion implantation.
Claim 6
Dependent Claim
54 words
A method according to claim 1, wherein for forming the pn junction, the first layer, being low doped, is epitaxially grown on a third layer of the first conducting type, the first and third layer forming the substrate, and the second layer, being highly doped, is epitaxially grown on top of the first layer.
Claim 7
Dependent Claim
70 words
A method according to claim 3, wherein for forming an edge termination, a mask is applied to an area surrounding a defect, the mask comprising openings that exhibit a decreasing size in a direction towards the defect, a dopant is added by ion implantation through the mask wherein an edge termination is created having a decreasing concentration of dopants of the second conducting type in a direction towards the micropipe.
Claim 8
Dependent Claim
77 words
A method according to claim 3, wherein for forming an edge termination, a mask is applied to an area surrounding a defect, the mask comprising openings, where the distance between the openings is increasing in a direction towards the defect, a dopant is added into the first layer by ion implantation through the mask, wherein an edge termination is created having a decreasing concentration of dopants of the second conducting type in a direction towards the micropipe.
Claim 9
Dependent Claim
41 words
A method according to claim 3, wherein for forming an edge termination, a zone, having a doping of the second conducting type, is formed by ion implantation into an area surrounding a hollow defect and is surrounded by the second layer.
Claim 10
Dependent Claim
50 words
A method according to claim 3, wherein for forming an edge termination, concentric discrete zones, having a doping of the second conducting type, surrounding the hollow defect, having stepwise decreasing doping concentration towards the hollow defect and being surrounded by the third layer, are formed by masking and ion implantation.
Claim 11
Dependent Claim
35 words
A method according to claim 5, wherein the implant used to form termination zones of p-conducting type is aluminum, boron or gallium, while the implant used to form JTE zones of n-conducting type is nitrogen.
Claim 12
Dependent Claim
74 words
A method according to claim 1, wherein for forming a pn junction with an edge termination, at least two layers of the second conducting type are epitaxially grown on top of the lowly doped first layer of the first conducting type, the doping concentration of each new second conducting type layer is successively increased, and the layers of the second conducting type are, through masking and etching, formed to have successively stepwise reduced areas.
Claim 13
Dependent Claim
34 words
A method according to claim 4, wherein for forming an edge termination, the second layer is, through masking and etching, formed to have a stepwise reduced thickness in a direction towards the hollow defect.
Claim 14
Dependent Claim
32 words
A method according to claim 3, wherein for forming an edge termination, a layer of semi insulating polycrystalline silicon is epitaxially grown adjacent to the second layer and surrounding the hollow defect.
Claim 15
Dependent Claim
24 words
A method according to claim 3, wherein the pn-junction is a part of any of a MISFET, an IGBT, a JFET or a FCT.
References Cited (Backward Citations)
US5914499A
Cited
JPH0927489A
Cited
US5967795A
Cited
US5972801A
Cited
US5932894A
Cited
US5915194A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-08-08 | 2004-02-07 | 2004-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-08-08 | 2008-02-07 | 2008-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-08-08 | 2012-02-07 | 2012-08-08 | $7700.00 | Window Closed / Lapsed |