Method for the production of semiconductor devices with an integral heatsink and of related semiconductor equipment

• US 3,973,320 A
• Filed: 09/03/1974
• Issued: 08/10/1976
• Est. Priority Date: 09/06/1973
• Status: Expired due to Term

• Current Assignee: Giovanni Greco, Maurizio Tomassini
• Original Assignee: Giovanni Greco, Maurizio Tomassini
• Inventors: Greco, Giovanni, Tomassini, Maurizio
• Primary Examiner(s): Hall, Carl E.
• Application Number:
  US05/502,307
• Time in Patent Office: 707 Days
• Field of Search: 29/580, 29/583, 29/591, 29/578, 357/81
• US Class Current: 438/464
• CPC Class Codes: H01L 21/308 using masks H01L21/3063, H01L21/3065 take precedence
• CPC Class Codes: H01L 21/4871 Bases, plates or heatsinks
• CPC Class Codes: H01L 21/78 with subsequent division of the substrate into plural individual devices cutting to change the surface-physical characteristics or shape of semiconductor bodies H01L21/304

Abstract

A process for producing a semiconductor device with an integral heatsink involving applying a coating of dielectric to a sheet of semiconductor material, removing part of the dielectric coating by etching to leave specific sink zones, coating the zones with a metal layer, bonding the assembly to a support with adhesive, depositing a layer of metal to the non-adhered surface of the semiconductor sheet in areas corresponding to the sink zones, and removing semiconductor material from the body of the sheet between the sink zones to produce mesa profile units with heatsinks.

Claims

1. A process for the production of a semiconductor device with an integral heatsink, starting with a sheet of semiconductor material having a P / N junction, comprising the steps of

uniformly coating both surfaces of the sheet of semiconductor material with a layer of dielectric,

removing by photoetching from a finite number of zones the layer of dielectric from one surface of said sheet to form a finite number of locations for the sinks,

coating the finite number of zones with a first flexible metal layer,

depositing a metal layer over said first flexible metal layer at the approximate areas of said zones to establish the sink formation,

bonding the said one surface of said sheet and its associated coatings with an adhesive to a support,

thinning down the other surface of said sheet of semiconductor material,

depositing a second flexible metal layer over said other surface of said sheet,

and removing semiconductor material from the body of said sheet in the intersticial spaces between and among the said zones to produce the separation of the semiconductor units with Mesa profiles which are equipped with sinks.

2. A process for the production of a semiconductor device as claimed in claim 1, wherein the step of coating the sheet with a layer of dielectric consists of covering said sheet of semiconductor material uniformly with a flexible layer of oxide by heating in an oxidizing atmosphere.

3. A process for the production of a semiconductor device as claimed in claim 1, wherein the step of coating the sheet with a layer of dielectric consists of covering said sheet of semiconductor material uniformly with a flexible layer of dielectric through use of a cathodic deposition with radio frequency.

4. A process for the production of a semiconductor device as claimed in claim 1, wherein the step of coating the sheet with dielectric consists of coating said sheet of semiconductor material uniformly with a flexible layer of dielectric using a precipitation in vacuum.

5. A process for the production of a semiconductor device as claimed in claim 1, wherein the step of coating the sheet with dielectric consists of covering said sheet of semiconductor material with a flexible coating of dielectric by a reactive deposition of silicon dioxide at a low temperature.

6. A process for the production of a semiconductor device as claimed in claim 1, wherein the step of coating the sheet with dielectric consists of coating said sheet of semiconductor material with a flexible layer of dielectric with an anodic oxidation base.

7. A process for the production of a semiconductor device as claimed in claim 1, wherein the step of coating the sheet with dielectric consists of coating said sheet of semiconductor material with a flexible layer of dielectric on the base of a deposition of oxides in the form of an emulsion.

8. A process for the production of a semiconductor device as claimed in claim 1, wherein said coating with the first flexible metal layer comprises the operations of depositing upon one surface of the sheet, a flexible metal layer, and of removing by photoetching the metal material from said layer restrictively at the external areas of the surface of said zones.

9. A process for the production of a semiconductor device as claimed in claim 1, wherein said coating with the first flexible metal layer comprises the operations of placing a metal screen upon the one surface of the sheet, and of depositing a flexible metal layer through the openings in said screen.

10. A process for the production of a semiconductor device as claimed in claim 8, wherein said flexible metal layer is deposited by a vapor-phase precipitation in vacuum.

11. A process for the production of a semiconductor device as claimed in claim 8, wherein said flexible metal layer is deposited by a cathodic deposition at low pressure.

12. A process for the production of a semiconductor device as claimed in claim 8, wherein said flexible metal layer is deposited by an electrolytic procedure.

13. A process for the production of a semiconductor device as claimed in claim 8, wherein said flexible metal layer is deposited by means of a chemical process, without the passage of any current.

14. A process for the production of a semiconductor device as claimed in claim 1, wherein said thinning operation on the surface of the sheet of the semiconductor material is done by a mechanical process.

15. A process for the production of a semiconductor device as claimed in claim 1, wherein said thinning operation on the surface of the sheet of the semiconductor material is done by an electrochemical process.