SINGLE-CRYSTAL SILICON CARBIDE DISPLAY DEVICE

• US 3,636,397 A
• Filed: 04/10/1969
• Issued: 01/18/1972
• Est. Priority Date: 11/24/1967
• Status: Expired due to Term

• Current Assignee: Arrigo Addamiano, Ronald J. Perusek
• Original Assignee: Arrigo Addamiano, Ronald J. Perusek
• Inventors: Addamiano, Arrigo, Perusek, Ronald J.
• Primary Examiner(s): Kominski, John
• Assistant Examiner(s): O'Reilly, David
• Application Number:
  US04/815,047
• Time in Patent Office: 1,013 Days
• Field of Search: 313/108,109.5 317/235 250/217SS,211S 29/580,583,589
• US Class Current: 313/500
• CPC Class Codes: H01L 21/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 27/00 Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate details thereof H01L23/00, H01L29/00 - H10K10/00; assemblies consisting of a plurality of individual solid state devices H01L25/00
• CPC Class Codes: H01L 29/1608 Silicon carbide
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/343 characterised by the doping materials
• CPC Class Codes: Y10S 148/107 Melt
• CPC Class Codes: Y10S 148/148 Silicon carbide
• CPC Class Codes: Y10S 438/931 Silicon carbide semiconductor

Abstract

The display device is a wafer of N-type silicon carbide having lines or segments of lines scribed into one face in a selected design such as an alpha-numeric or a grid of closely spaced dots. After scribing, the wafer is diffused with P-type dopants such as boron and aluminum. Contact to the P-type material within the scribed lines is made by vacuum evaporation of copper-silver. The wafer faces are then lapped to remove the metallizing and P-type layer except within the scribed lines. A connection is then made to the N-type material, and individual connections to each P-type scribed-line segment. By selective energization of line segments, various luminous letters, numerals or characters may be formed which are seen through the N-type material.

Claims

2. A display device as in claim 1 wherein the grooves are disposed as framing, cross and diagonal lines to form an alpha-numeric indicator.

3. A display device as in claim 1 wherein the grooves are disposed in parallel and closely spaced, and cross grooves break up the original grooves into segments to form a grid indicator of closely spaced luminous spots.

4. A display device as in claim 1 wherein the P-type dopant comprises boron and aluminum.

5. A display device as in claim 1 wherein the contact metal deposited in the grooves comprises copper and silver.

6. The method of making a single-crystal display device which comprises obtaining a wafer of N-type silicon carbide, scribing one face of the wafer with grooves forming lines disposed to create intelligence-conveying patterns, diffusing a P-type dopant into said wafer, said grooves penetrating into said wafer a depth exceeding the diffusion depth of said P-type dopant, vacuum evaporating contact metal onto said P-type material, removing the contact metal and the P-type material from the face of the wafer except within the scribed grooves, and making a connection to the exposed N-type material and individual connections to the metal contacting the P-type material within the grooves.

7. The method of claim 6 wherein portions of the grooves are masked prior to dopant diffusion and contact metal evaporation in order to have line segments formed by the unmasked portions, and individual connections are made to the line segments.

8. The method of claim 6 wherein said one face is scribed with cross grooves after dopant diffusion and contact metal evaporation in order to break up the original grooves into segments, and individual connections are made to the groove segments.