Semiconductor devices and methods for generating light
View Patent ↗Semiconductor devices and a method for generating light in a semiconductor device are invented and disclosed. The method includes the steps of forming a vertical cavity surface emitting laser including an active region and an oxide layer, the active region separated from the oxide layer and configured to generate light in response to an injected current and introducing an implant layer adjacent and underneath the oxide layer to confine the injected current to a region of the device where charge carriers are combining to generate light. The semiconductor devices include an implant layer between the oxide layer and the active region. The implant layer prevents lateral leakage current from exiting a region of the device where charge carriers are combining to generate light.
1. A light-emitting semiconductor device, comprising:
an active region between an n-type distributed Bragg reflector and a p-type distributed Bragg reflector, the active region arranged to generate light in response to an injected charge introduced by a current flowing from an electrical contact coupled to the p-type distributed Bragg reflector;
an oxide layer in contact with the p-type distributed Bragg reflector and opposed to the electrical contact, the oxide layer having an oxide layer aperture that directs the injected charge into the active region; and
an implant layer arranged between the oxide layer and the active region, the implant layer formed by implanting ions of a non-semiconductor element into a semiconductor material to make the implant layer an electrical insulator, the implant layer having an implant layer aperture that directs the injected charge to a region of the device where charge carriers are combining to emit light, the implant layer aperture being between about 20% to 110% larger than the oxide layer aperture.
2. The device of claim 1 , wherein the implant layer extends into the p-type distributed Bragg reflector towards the center of the device.
3. The device of claim 2 , wherein the oxide layer extends into the p-type distributed Bragg reflector towards the center of the device further than the implant layer.
4. The device of claim 1 , wherein the implant layer contacts an upper surface of the active region.
5. The device of claim 1 , wherein the implant layer extends vertically into the active region.
6. The device of claim 1 , wherein the implant layer forms an aperture of about 11 micrometers to 15 micrometers.
7. The device of claim 1 , wherein the semiconductor material of the implant layer comprises aluminum, gallium, and arsenide.
8. The device of claim 7 , in which the oxide layer consists essentially of Al x Ga 1-x As, where x≧0.9.
9. The device of claim 1 , structured to generate light having a wavelength between 620 nm and 1650 nm.
10. The device of claim 9 , structured to generate light having a wavelength of approximately 850 nm.
11. A method for generating light, the method comprising:
forming a vertical cavity surface emitting laser including an active region and an oxide layer, the active region separated from the oxide layer, the active region between an n-type distributed Bragg reflector and a p-type distributed Bragg reflector and configured to generate light in response to an injected current flowing from an electrical contact coupled to the p-type distributed Bragg reflector, the oxide layer having an oxide layer aperture that directs the injected current into the active region; and
injecting ions of an element that is an electrical insulator into a semiconductor material adjacent to the oxide layer to form an implant layer adjacent the oxide layer, the implant layer confining the injected current to a region of the device where charge carriers are combining to emit light, the implanted layer aperture being between about 20% to 110% larger than the oxide layer aperture.
12. The method of claim 11 , wherein the semiconductor material comprises Aluminum, Gallium, and Arsenide.
13. The method of claim 11 , wherein injecting ions of an element that is an electrical insulator into a semiconductor material to form an implant layer comprises extending the implant layer into the p-type distributed Bragg reflector.
14. The method of claim 13 , wherein extending the implant layer into the p-type distributed Bragg reflector results in less penetration of the p-type distributed Bragg reflector by the implant layer than penetration due to the oxide layer.
15. The method of claim 11 , wherein injecting ions of an element that is an electrical insulator into a semiconductor material to form an implant layer comprises extending the implant layer vertically in the direction of the active region.
16. The method of claim 11 , wherein injecting ions of an element that is an electrical insulator into a semiconductor material to form an implant layer comprises extending the implant layer vertically into the active region.
17. The method of claim 11 , wherein injecting ions of an element that is an electrical insulator into a semiconductor material to form an implant layer comprises introducing a sufficient distribution of ions to make the implant layer react to injected current like an electrical insulator.
18. The method of claim 11 , wherein injecting ions of an element that is an electrical insulator into a semiconductor material to form an implant layer comprises blocking lateral leakage of the injected current under the oxide layer.
19. The method of claim 11 , further comprising:
adjusting an implant aperture to vary a signal modulation bandwidth.
20. The method of claim 11 , wherein forming a vertical cavity surface emitting laser comprises structuring quantum wells to generate light having a wavelength of approximately 850 nm.