Contact structure for light emitting device
AssigneeBell Telephone Laboratories, Incorporated
InventorJohn J. Bastek
Life of this patent
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Abstract
A contact structure to the light emitting surface 19 of a light emitting device 10 having an array of small distributed contacts 14 is made by selectively depositing a larger area bonding pad 15 over a portion of the distributed contacts. The small contacts not covered by the bonding pad then are removed by sputter etching and contact to the device is made by wire bonding a lead 17 to the bonding pad.
Claims7
The method of making a substantially ohmic low resistance contact to the light emitting surface 19 of a light emitting semiconductor device 10 comprising the steps of;
- (1) forming on said light emitting surface an array of small metallic contacts 14,
- (2) heating said device to alloy a portion of each said contact to said light emitting surface,
- (3) selectively depositing a large area metal bonding pad 15 on said light emitting surface and over a plurality of said small contacts,
- (4) subjecting the light emitting contact surface to sputter etching for a period of time sufficient to entirely remove the small contacts not covered by the bonding pad, and
- (5) attaching a wire lead to the surface of said bonding pad.
The method of making a substantially ohmic low resistance contact to the light emitting surface of a light emitting semiconductor device which is of the III-V compound semiconductor type comprising the steps of
- (1) forming on said light emitting surface a regular array of small metallic contacts,
- (2) heating said device to alloy a portion of each said contact to said light emitting surface,
- (3) selectively depositing a large area metal bonding pad on said light emitting surface and over a plurality of said small contacts, said pad having a thickness at least about an order of magnitude greater than the thickness of small contacts,
- (4) subjecting the contact surface to sputter etching for a period sufficient to entirely remove the small contacts not covered by the bonding pad, and
- (5) attaching a wire lead to the surface of said bonding pad.
Dependencies are inferred from the claim text.