Surface emitting laser and photodiode, manufacturing method therefor, and optoelectric integrated circuit using the surface emitting laser and the photodiode

• US 20020137245A1
• Filed: 03/14/2002
• Published: 09/26/2002
• Est. Priority Date: 03/26/2001
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Harada, Atsushi, Kitamura, Shojiro, Ide, Tsugio, Kaneko, Takeo
• Granted Patent: US 6,687,268 B2
• Time in Patent Office: Days
• US Class Current: 438/22
• CPC Class Codes: G02B 6/42 Coupling light guides with opto-electronic elements
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/4232 using the surface tension of fluid solder to align the elements, e.g. solder bump techniques flip-chip mounting techniques in assembly of semiconductor devices H01L24/81
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/0208 Semi-insulating substrates
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/0237 by soldering
• CPC Class Codes: H01S 5/0422 with n- and p-contacts on the same side of the active layer
• CPC Class Codes: H01S 5/04257 having positive and negative electrodes on the same side of the substrate
• CPC Class Codes: H01S 5/0683 by monitoring the optical output parameters
• CPC Class Codes: H01S 5/18311 using selective oxidation

Abstract

The present invention provides a surface emitting laser and a photodiode which permit secure mounting even in mounting by flip chip bonding, and high-speed modulation, a manufacturing method therefor and a optoelectric integrated circuit using the surface emitting laser and the photodiode. A semiconductor stacked layers 2 stacked on a semiconductor substrate 1 has a light emitting portion 2A and a reinforcing portion 2B formed with a recessed portion 6 provided therebetween, and a p-type ohmic electrode 4 and a n-type ohmic electrode 5 are formed on the top of the reinforcing portion 2B. The p-type ohmic electrode 4 is electrically connected to a p-type contact layer 21 through a contact hole 41a vertically formed in polyimide buried in the recessed portion 6 to permit supply of a current to the light emitting portion 2A in the thickness direction. The recessed portion 6 has a groove 6a formed to reach the semiconductor substrate 1, thereby suppressing the parasitic capacity between the p-type ohmic electrode 4 and the n-type ohmic electrode 5.

Claims

1. A surface emitting laser comprising a semiconductor substrate, a semiconductor stacked layers stacked on the substrate and divided into a light emitting portion and a reinforcing portion by a recessed portion, an insulating material buried in the recessed portion, and a pair of electrodes for applying a voltage to pass a current in the thickness direction of the light emitting portion,

wherein the pair of electrodes has an external connecting portion formed on the upper surface of the reinforcing portion.

2. The surface emitting laser according to claim 1, wherein one of the pair of electrodes is electrically connected to the lower end of the light emitting portion through a contact hole vertically extending in the insulating material.

3. The surface emitting laser according to claim 1 or 2, wherein the bottom of the recessed portion reaches the surface of the semiconductor substrate over the entire length of the bottom in order to attain non-conduction between the lower end of the light emitting portion and the lower end of the reinforcing portion.

11. A optoelectric integrated circuit comprising at least an optical waveguide, a mirror for incidence into the optical waveguide, a mirror for emission from the optical waveguide, and electric wiring;

wherein a surface emitting laser of claims 1 to 3, a laser driving circuit for driving the surface emitting laser, a photodiode of claims 6 to 8, and an amplifier circuit for detecting signals from the photodiode are mounted on the electric wiring by flip chip bonding.

4. A method of manufacturing a surface emitting laser comprising:

the step of vertically etching a semiconductor stacked layers formed on a semiconductor substrate to form a recessed portion for dividing the semiconductor stacked layers into a light emitting portion and a reinforcing portion;

the step of further vertically etching the bottom of the recessed portion until the bottom reaches the surface of the semiconductor substrate over the whole length of the bottom to form a groove for attaining non-conduction between the lower end of the light emitting portion and the lower end of the reinforcing portion;

the step of filling the recessed portion including the groove with an insulating material;

the step of forming a contact hole in the insulating material so that the contact hole vertically extends and connects to the lower end of the light emitting portion; and

the step of forming electrodes on the upper surface of the reinforcing portion so that the electrodes are respectively electrically connected to the upper ends of the light emitting portion and the contact hole.

5. The method of manufacturing a surface emitting laser according to claim 4, wherein in the step of forming the groove, the groove is formed so that a portion connected to the lower end of the contact hole remains at the lower end of the light emitting portion.

6. A photodiode comprising a semiconductor substrate, a semiconductor stacked layers divided into a light receiving portion and a reinforcing portion by a recessed portion, an insulating material buried in the recessed portion, and a pair of electrodes for detecting a current flowing in the thickness direction of the light receiving portion due to incidence of light,

wherein the pair of electrodes has an external connecting portion formed on the upper surface of the reinforcing portion.

7. The photodiode according to claim 6, wherein one of the pair of electrodes is electrically connected to the lower end of the light receiving portion through a contact hole vertically extending in the insulating material.

8. The photodiode according to claim 6 or 7, wherein the bottom of the recessed portion reaches the surface of the semiconductor substrate over the entire length of the bottom in order to attain non-conduction between the lower end of the light receiving portion and the lower end of the reinforcing portion.

9. A method of manufacturing a photodiode comprising:

the step of vertically etching a semiconductor stacked layers formed on a semiconductor substrate to form a recessed portion for dividing the semiconductor stacked layers into a light receiving portion and a reinforcing portion;

the step of further vertically etching the bottom of the recessed portion until the bottom reaches the surface of the semiconductor substrate over the whole length of the bottom to form a groove for attaining non-conduction between the lower end of the light receiving portion and the lower end of the reinforcing portion;

the step of filling the recessed portion including the groove with an insulating material;

the step of forming a contact hole in the insulating material so that the contact hole vertically extends and connects to the lower end of the light receiving portion; and

the step of forming electrodes on the upper surface of the reinforcing portion so that the electrodes are respectively electrically connected to the upper ends of the light receiving portion and the contact hole.

10. The method of manufacturing a photodiode according to claim 9, wherein in the step of forming the groove, the groove is formed so that a portion connected to the lower end of the contact hole remains at the lower end of the light receiving portion.