Patent US5318915A successfully refreshed from Google Patents.
US5318915A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming a p-n junction in silicon carbide
Assignee: Intellectual Ventures Holding 81 LLC
•
Filing: 1993-01-25
•
Granted: 1994-06-07
•
Expires: 2013-01-25
Abstract
Abstract A method for forming a p-n junction in silicon carbide includes the steps of amorphizing a portion of a monocrystalline silicon carbide substrate, implanting dopant ions into the amorphous portion of the substrate and then recrystallizing the amorphous portion to thereby form a substantially monocrystalline region including the dopant ions. In particular, the amorphizing step includes the steps of masking an area on the face of the monocrystalline silicon carbide substrate and then directing electrically inactive ions to the masked area so that an amorphous region in the substrate is formed. Accordingly, the amorphous region has sidewalls extending to the face that are substantially orthogonal to the bottom edge of the amorphous region. Once the amorphized region is defined, electrically active dopant ions are implanted into the amorphous region. The dopant ions are then diffused into the amorphous region and become uniformly distributed. Next, the doped amorphized region is recrystallized to obtain a substantially monocrystalline doped region. If the region surrounding the recrystallized region are of opposite conductivity type, a vertically walled p-n junction is formed.
Inventors
- 👤 Bantval J. Baliga
- 👤 Dev Alok
- 👤 Mohit Bhatnagar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:25
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/21; H10P30/202; H10P30/204; H10P30/2042; H10P30/218; H10P30/28; Y; Y10; Y10S; Y10S438/00; Y10S438/931
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
101 words
A method of forming a silicon carbide junction in a monocrystalline silicon carbide substrate, comprising the steps of: amorphizing a portion of a monocrystalline silicon carbide substrate to thereby define an amorphous silicon carbide region in the monocrystalline silicon carbide substrate and extending to a face thereof; subsequently implanting dopant ions into a surface portion of said amorphous silicon carbide region; uniformly distributing the dopant ions in the surface portion, into said amorphous silicon carbide region by annealing said amorphous silicon carbide region; and recrystallizing said amorphous silicon carbide region to thereby form a substantially monocrystalline region including the dopant ions.
Claim 2
Independent Claim
101 words
A method of forming a silicon carbide junction in a monocrystalline silicon carbide substrate, comprising the steps of: amorphizing a portion of a monocrystalline silicon carbide substrate to thereby define an amorphous silicon carbide region in the monocrystalline silicon carbide substrate and extending to a face thereof; subsequently implanting dopant ions into a surface portion of said amorphous silicon carbide region; uniformly distributing the dopant ions in the surface portion, into said amorphous silicon carbide region by annealing said amorphous silicon carbide region; and recrystallizing said amorphous silicon carbide region to thereby form a substantially monocrystalline region including the dopant ions.
Claim 3
Dependent Claim
41 words
The method of claim 1, wherein the substrate is of first conductivity type and wherein said dopant ion implanting step comprises the step of implanting dopant ions of second conductivity type into the surface portion of said amorphous silicon carbide region.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein said uniformly distributing step and said recrystallizing step are performed simultaneously.
Claim 5
Dependent Claim
39 words
The method of claim 1 wherein said amorphizing step comprises the step of: implanting ions into the portion of the monocrystalline silicon carbide substrate, such that the implanted ions convert the portion into a region of amorphous silicon carbide.
Claim 6
Dependent Claim
65 words
The method of claim 4 wherein said ion implanting step comprises the steps of: masking an area on the face of the monocrystalline silicon carbide substrate; and directing ions to the face of the monocrystalline silicon carbide substrate, such that the ions implant into the substrate in the region defined by the masked area and convert the portion into a region of amorphous silicon carbide.
Claim 7
Dependent Claim
40 words
The method of claim 5, wherein said ion directing step comprises the step of directing electrically inactive ions, selected from the group consisting of silicon, hydrogen, neon, helium, carbon and argon to the face of the monocrystalline silicon carbide substrate.
Claim 8
Independent Claim
124 words
A method of forming a silicon carbide junction in a monocrystalline silicon carbide substrate, comprising the steps of: masking an area on a face of a monocrystalline silicon carbide substrate; directing electrically inactive ions to the face, such that the ions implant into the substrate in the region defined by the masked area and convert a portion of the monocrystalline silicon carbide substrate into a region of amorphous silicon carbide; subsequently implanting dopant ions into a surface portion of said amorphous silicon carbide region; uniformly distributing the dopant ions in the surface portion, into said amorphous silicon carbide region by annealing said amorphous silicon carbide region; and recrystallizing said amorphous silicon carbide region to thereby form a substantially monocrystalline region including the dopant ions.
Claim 9
Independent Claim
124 words
A method of forming a silicon carbide junction in a monocrystalline silicon carbide substrate, comprising the steps of: masking an area on a face of a monocrystalline silicon carbide substrate; directing electrically inactive ions to the face, such that the ions implant into the substrate in the region defined by the masked area and convert a portion of the monocrystalline silicon carbide substrate into a region of amorphous silicon carbide; subsequently implanting dopant ions into a surface portion of said amorphous silicon carbide region; uniformly distributing the dopant ions in the surface portion, into said amorphous silicon carbide region by annealing said amorphous silicon carbide region; and recrystallizing said amorphous silicon carbide region to thereby form a substantially monocrystalline region including the dopant ions.
Claim 10
Dependent Claim
41 words
The method of claim 7, wherein the substrate is of first conductivity type and wherein said dopant ion implanting step comprises the step of implanting dopant ions of second conductivity type into the surface portion of said amorphous silicon carbide region.
Claim 11
Dependent Claim
40 words
The method of claim 7, wherein said electrically inactive ion directing step comprises the step of directing ions, selected from the group consisting of silicon, hydrogen, neon, helium, carbon and argon to the face of the monocrystalline silicon carbide substrate.
Claim 12
Dependent Claim
17 words
The method of claim 7, wherein said uniformly distributing step and said recrystallizing step are performed simultaneously.
References Cited (Backward Citations)
US4567502A
Cited
US4916507A
Cited
US4945394A
Cited
US5087576A
Cited
US5030580A
Cited
US5254484A
Cited
US5248385A
Cited
US5270244A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-06 | 1997-12-06 | 1998-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-06 | 2001-12-06 | 2002-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-06 | 2005-12-06 | 2006-06-07 | $7700.00 | Window Closed / Lapsed |