Semiconductor laser having electro-static discharge protection

• US 6,185,240 B1
• Filed: 01/30/1998
• Issued: 02/06/2001
• Est. Priority Date: 01/30/1998
• Status: Expired due to Term

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Jiang, Wenbin, Claisse, Paul R., Kiely, Philip A.
• Primary Examiner(s): Anderson, Bruce C
• Assistant Examiner(s): LEUNG, QUYEN PHAN
• Application Number:
  US09/015,896
• Time in Patent Office: 1,103 Days
• Field of Search: 372/38, 372/50, 372/96
• US Class Current: 372/50.124
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• CPC Class Codes: H01S 5/0261 Non-optical elements, e.g. laser driver components, heaters H01S5/0265 takes precedence
• CPC Class Codes: H01S 5/04256 characterised by the configuration
• CPC Class Codes: H01S 5/06825 Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation
• CPC Class Codes: H01S 5/183 having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
• CPC Class Codes: H01S 5/18394 Apertures, e.g. defined by the shape of the upper electrode

Abstract

A vertical cavity surface emitting laser (103) and a diode (105) is provided. The diode (105) is electrically coupled in reverse parallel to the vertical cavity surface emitting laser (103), thereby providing a portion of protection against electro-static discharge damage to the vertical cavity surface emitting laser (103).

Claims

1. A semiconductor laser having electro-static discharge protection comprising:

a vertical cavity surface emitting laser having a first stack of distributed Bragg reflectors, a second stack of distributed Bragg reflectors, an active region sandwiched therebetween the first and second stacks of distributed Bragg reflectors, a first electrical terminal, and a second electrical terminal; and

a diode having a first stack of distributed Bragg reflectors, a second stack of distributed Bragg reflectors, an active region sandwiched therebetween the first and second stacks of distributed Bragg reflectors, a third electrical terminal and a fourth electrical terminal, where the first electrical terminal and the third electrical terminal are coupled together and the second electrical terminal and the fourth electrical terminal are coupled together, the vertical cavity surface emitting laser and the diode integrated on a common chip, and coupled together in reverse parallel thus providing protection against electrostatic discharge damage to the vertical cavity surface emitting laser.

2. A semiconductor laser having electro-static discharge protection as claimed in claim 1 wherein the diode is a p-i-n diode.

3. A semiconductor laser having electro-static discharge protection as claimed in claim 2 wherein the p-i-n diode has a breakdown voltage between 10-20 V.

4. A semiconductor laser having electro-static discharge protection as claimed in claim 2 wherein the p-i-n diode has a second breakdown voltage of more than 100 V.

5. A vertical cavity surface emitting laser comprising:

a substrate;

a first stack of distributed Bragg reflectors disposed on the substrate, the first stack of distributed Bragg reflectors including a plurality of alternating layers;

a first active area overlying the first stack of distributed Bragg reflectors;

a second stack of distributed Bragg reflectors having a surface overlying the first active area, the second stack of distributed Bragg reflectors including a plurality of alternating layers;

a first trench having a first width and a first depth, wherein the first depth of the first trench extends into a portion of the second stack of distributed Bragg reflectors and defines a vertical cavity surface emitting laser;

a second trench with a second width and a second depth, wherein the second depth of the second trench extends into a portion of the substrate, the second trench defines and isolates a diode;

a third trench having a third width and a third depth, wherein the third trench is located inside the second trench and extends into contact with the first stack of distributed Bragg reflectors;

a fourth trench having a fourth width and a fourth depth, wherein the fourth depth extends into contact with the first stack of distributed Bragg reflectors;

a dielectric layer covering the surface of the second stack of distributed Bragg reflectors, the dielectric layer defining an opening adjacent the first trench region exposing a portion of the second stack of distributed Bragg reflectors, an opening exposing a portion of the first stack of distributed Bragg reflectors adjacent the active area, and an opening exposing a contact through the second stack of distributed Bragg reflectors of the diode; and

a first metal layer electrically connecting the exposed portion of the second stack of distributed Bragg reflectors adjacent the first trench with the portion of the first stack of distributed Bragg reflectors adjacent the active area in the second trench and a second metal layer electrically connecting the exposed portion of the first stack of distributed Bragg reflectors in the fourth trench with the exposed portion of the second stack of distributed Bragg reflectors of the diode.