Deep diode solid state transformer

• US 4,024,565 A
• Filed: 02/27/1975
• Issued: 05/17/1977
• Est. Priority Date: 10/30/1973
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Anthony, Thomas R., Cline, Harvey E.
• Primary Examiner(s): Wojciechowicz, Edward J.
• Application Number:
  US05/553,903
• Time in Patent Office: 810 Days
• Field of Search: 357/51, 357/55, 357/60, 357/89, 357/88, 357/90
• US Class Current: 257/45
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01L 21/24 Alloying of impurity materials, e.g. doping materials, electrode materials, with a semiconductor body H01L21/182 takes precedence
• CPC Class Codes: H01L 23/522 including external interconnections consisting of a multilayer structure of conductive and insulating layers inseparably formed on the semiconductor body
• CPC Class Codes: H01L 27/0814 Diodes only
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An array of columnar structures are provided in a body of semiconductor material. The material of each columnar structure is recrystallized material of the body having solid solubility of dopant metal therein. Means are provided for connecting the columnar structures into two series electrical circuit arrangements to function respectively as the primary and secondary windings of a deep diode solid state transformer.

Claims

1. A solid state transformer comprising

a body of semiconductor material having two opposed major surfaces forming respectively the top and bottom surfaces of the body, a predetermined level of resistivity, a predetermined first type conductivity, a preferred crystal structure and a vertical axis substantially perpendicular to the major opposed surfaces and a first preferred crystal axis of the material;

at least one of the opposed major surfaces having a predetermined crystal planar orientation which is one selected from the group consisting of (100), (110) and (111);

a plurality of regions of recrystallized semiconductor material of the body having a second and opposite type conductivity than that of the body and a predetermined level of resistivity formed in the body and each of which has a vertical axis so oriented as to be aligned approximately parallel with the first preferred crystal axis;

each of the plurality of regions extending between, and terminating in, the opposed surfaces and providing a low electrical resistance path for conducting an electrical current between the opposed major surfaces;

the recrystallized material of each region is formed in situ by the migration of a melt of metal-rich semiconductor material of the body by thermal gradient zone melting at a predetermined elevated temperature along a thermal gradient substantially parallel with the first crystal axis and the vertical axis of the body and has a predetermined level of concentration of the metal of the melt as determined by the solid solubility limit of that metal in that semiconductor material at that predetermined elevated temperature of migration and the metal is distributed substantially uniformly throughout the entire region;

the metal consisting of at least one dopant impurity material to impart the type conductivity and level of resistivity to the recrystallized material of the region;

a P-N junction by the contiguous surfaces of the recrystallized material of each region and the material of the body;

first means for electrically connecting selective ones of the plurality of regions into a series electrical circuit arrangement to function as a primary winding of the transformer, and

second means for electrically connecting the remaining ones of the plurality of regions into a series electrical circuit arrangement so as to function as a secondary winding of the transformer.

2. The solid state transformer of claim 1 wherein

the preferred planar crystal orientation is (110), and

the first crystal axis is <

110 >

.

3. The solid state transformer of claim 1 wherein

the preferred planar crystal orientation is (110), and

the first crystal axis is <

110 >

.

4. The solid state transformer of claim 1 wherein

the semiconductor material is one selected from the group consisting of silicon, silicon carbide, germanium and gallium arsenide.

5. The solid state transformer of claim 4 wherein

the semiconductor material is silicon having N-type conductivity and the solid solubility dopant material is aluminum.

6. The solid state transformer of claim 5 wherein

the concentration of the aluminum is 2 ×

10¹⁹ atoms per cubic centimeter.

7. The solid state transformer of claim 1 wherein

each P-N junction is a step junction.

8. The solid state transformer of claim 1 wherein

the preferred planar crystal orientation is (111), and

the first crystal axis is <

111 >

.

9. The solid state transformer of claim 1 wherein

the preferred planar crystal orientation is (100), and

the first crystal axis is <

100 >

.

10. The solid state transformer of claim 4 wherein

the preferred planar crystal orientation is (111), and

the first crystal axis is <

111 >

.

11. The solid state transformer of claim 5 wherein

the preferred planar crystal orientation is (111), and

the first crystal axis is <

111 >

.

12. The solid state transformer of claim 4 wherein

the preferred planar crystal orientation is (100), and

the first crystal axis is <

100 >

.

13. The solid state transformer of claim 5 wherein

the preferred planar crystal orientation is (100), and

the first crystal axis is <

100 >

.