METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• US 20130330913A1
• Filed: 02/25/2011
• Published: 12/12/2013
• Est. Priority Date: 02/25/2011
• Status: Active Grant

• Current Assignee: Meijo University, Nikkiso Company Limited
• Original Assignee: Meijo University, Soko Kagaku Co Ltd
• Inventors: Iwaya, Motoaki, Amano, Hiroshi, Akasaki, Isamu
• Granted Patent: US 9,029,174 B2
• Time in Patent Office: Days
• US Class Current: 438/478
• CPC Class Codes: H01L 21/02365 Forming inorganic semiconducting materials on a substrate for light-sensitive devices H01L31/00
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate

Abstract

A structure includes a substrate, a template layer formed on the surface of the substrate and including an AlN layer, and a device structure portion formed by stacking AlGaN semiconductor layers on the template layer. For the structure, the AlN layer is irradiated from a side close to the substrate with a laser light with a wavelength by which the laser light passes through the substrate and the laser light is absorbed by the AlN layer, in a state in which the AlN layer receives compressive stress from the substrate. This allows the AlN layer to expand more than the surface of the substrate on at least an interface between the AlN layer and the substrate so as to increase the compressive stress, in order to remove the substrate from the AlN layer.

Claims

1. A method for manufacturing a semiconductor device, comprising

a lift-off process that includes, for a structure including a substrate, a template layer formed on the surface of the substrate and including an AlN layer, and a device structure portion formed by stacking AlGaN semiconductor layers on the template layer,

irradiating the AlN layer from a side close to the substrate with a laser light with a wavelength by which the laser light passes through the substrate and the laser light is absorbed by the AlN layer, in a state in which the AlN layer receives compressive stress from the substrate, so that the AlN layer expands more than the surface of the substrate on at least an interface between the AlN layer and the substrate so as to increase the compressive stress, in order to remove the substrate from the AlN layer.

2. The method for manufacturing the semiconductor device according to claim 1, wherein

the substrate is made of sapphire, and the surface of the substrate is {0001} plane, the wavelength of the laser light is 200 nm or less, and

the compressive stress received by the AlN layer from the substrate before the irradiation of the laser light is 10 MPa or more.

3. The method for manufacturing the semiconductor device according to claim 1, comprising

a dividing process in which the structure that is in a form of a wafer is divided into an element unit, before the lift-off process.

4. The method for manufacturing the semiconductor device according to claim 1, comprising

a dividing process in which at least the template layer and the device structure portion of the structure that is in a form of a wafer are divided into an element unit with the wafer state being kept, before the lift-off process.

5. The method for manufacturing the semiconductor device according to claim 1, comprising

a fixing process for fixing the surface of the device structure portion of the structure to a surface of a predetermined support member, before the lift-off process.

6. The method for manufacturing the semiconductor device according to claim 5, wherein

the fixing process includes:

a connection process for connecting the surface of the device structure portion of the structure and the surface of the support member in order that a gap is formed on at least a portion between them; and

a filling process of filling a filler into the gap.

7. The method for manufacturing the semiconductor device according to claim 1, wherein

the AlN layer is formed by growing AlN in a lateral direction on the surface of the substrate that is formed to have irregularities.

8. The method for manufacturing the semiconductor device according to claim 1, wherein

the template layer includes a laterally grown layer that is formed by growing AlN or AlGaN in a lateral direction on the surface of the AlN layer after the surface of the AlN layer is formed to have irregularities.

9. The method for manufacturing the semiconductor device according to claim 7, comprising

a cavity expanding process in which solvent is injected into a cavity generated by the lateral growth during the formation of the template layer in order to expand the cavity, before the lift-off process.

10. The method for manufacturing the semiconductor device according to claim 1, wherein

the lift-off process includes:

an irradiation process for removing at least a part of the substrate from the AlN layer by the irradiation of the laser light; and

an etching process for removing the substrate from the AlN layer by etching an interface of the AlN layer that is bonded to a part of the substrate not removed from the AlN layer, after the irradiation process.

11. The method for manufacturing the semiconductor device according to claim 1, wherein

the surface that is exposed by the removal of the substrate in the lift-off process is a rough surface.

12. The method for manufacturing the semiconductor device according to claim 8, comprising

a cavity expanding process in which solvent is injected into a cavity generated by the lateral growth during the formation of the template layer in order to expand the cavity, before the lift-off process.