Nitride semiconductor element and nitride semiconductor package

• US 9,905,419 B2
• Filed: 09/21/2016
• Issued: 02/27/2018
• Est. Priority Date: 11/16/2010
• Status: Active Grant

• Current Assignee: ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Takado, Shinya, Ito, Norikazu, Yamaguchi, Atsushi
• Primary Examiner(s): Malek, Maliheh
• Application Number:
  US15/271,759
• Publication Number:
  US 20170011911A1
• Time in Patent Office: 524 Days
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02499 Monolayers
• CPC Class Codes: H01L 21/02505 consisting of more than two layers
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/4825 Connection or disconnection of other leads to or from flat leads, e.g. wires, bumps, other flat leads
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/06051 Bonding areas having different shapes
• CPC Class Codes: H01L 2224/451 with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 23/3114 the device being a chip scale package, e.g. CSP
• CPC Class Codes: H01L 23/4952 the additional leads being a bump or a wire
• CPC Class Codes: H01L 23/49562 for devices being provided for in H01L29/00
• CPC Class Codes: H01L 24/06 of a plurality of bonding areas
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 29/045 : by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/154 : comprising at least one long range structurally disordered material, e.g. one-dimensional vertical amorphous superlattices
• CPC Class Codes: H01L 29/2003 : Nitride compounds
• CPC Class Codes: H01L 29/205 : in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/41758 : for lateral devices with structured layout for source or drain region, i.e. the source or drain region having cellular, interdigitated or ring structure or being curved or angular H01L29/41733 - H01L29/4175 take precedence
• CPC Class Codes: H01L 29/42316 : for field-effect transistors
• CPC Class Codes: H01L 29/66462 : with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
• CPC Class Codes: H01L 29/7784 : with delta or planar doped donor layer H01L29/7785 takes precedence
• CPC Class Codes: H01L 29/7787 : with wide bandgap charge-carrier supplying layer, e.g. direct single heterostructure MODFET
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/12032 : Schottky diode

Abstract

A nitride semiconductor element capable of accommodating GaN electron transfer layers of a wide range of thickness, so as to allow greater freedom of device design, and a nitride semiconductor element package with excellent voltage tolerance performance and reliability. On a substrate, a buffer layer including an AlN layer, a first AlGaN layer and a second AlGaN layer is formed. On the buffer layer, an element action layer including a GaN electron transfer layer and an AlGaN electron supply layer is formed. Thus, an HEMT element is constituted.

Claims

1. A nitride semiconductor element, comprising:

a Si substrate including a primary surface;

a buffer layer comprised of an AlN layer formed on the primary surface of the Si substrate, and an AlGaN laminated structure formed by laminating multiple AlGaN layers on the AlN layer, the buffer layer having a primary surface which has a c-plane orientation;

a Group III-nitride electron transfer layer formed on the AlGaN laminated structure; and

a Group III-nitride electron supply layer formed on the Group III-nitride electron transfer layer,

wherein the AlGaN laminated structure includes a reference AlGaN layer, and an AlGaN layer that is closer to the AlN layer, and

wherein the reference AlGaN layer has an a-axis average lattice constant, the AlGaN layer arranged in contact with a surface of the reference AlGaN layer has an a-axis in-plane lattice constant, wherein the surface of the reference AlGaN layer faces the AlN layer, and wherein the a-axis average lattice constant of the reference AlGaN layer is greater than the a-axis in-plane lattice constant of the AlGaN layer arranged in contact with the surface of the reference AlGaN layer, and lower than an original a-axis average lattice constant of the reference AlGaN layer.

2. The nitride semiconductor element of claim 1, wherein the reference AlGaN layer has an Al component that is lower than the Al component of the AlGaN layer that is closer to the AlN layer.

3. The nitride semiconductor element according to claim 2, wherein, in the AlGaN laminated structure, the difference in Al component between the reference AlGaN layer and the AlGaN layer arranged in contact with the surface of the reference AlGaN layer is 10% or more.

4. The nitride semiconductor element according to claim 2, wherein the Al component of the AlGaN layer is 50% and the Al component of the reference AlGaN layer is 10%.

5. The nitride semiconductor element according to claim 2, wherein the Al component of the AlGaN layer is 50% and the Al component of the reference AlGaN layer is 17%.

6. The nitride semiconductor element according to claim 2, wherein the Al component of the AlGaN layer is 50% and the Al component of the reference AlGaN layer is 20%.

7. The nitride semiconductor element according to claim 2, wherein the Al component of the AlGaN layer is 50% and the Al component of the reference AlGaN layer is 25%.

8. The nitride semiconductor element according to claim 1, wherein the AlN layer has a first a-axis average lattice constant, the Group III-nitride electron transfer layer has a second a-axis average lattice constant, and the a-axis average lattice constant of the reference AlGaN layer and the a-axis in-plane lattice constant of the AlGaN layer are greater than the first a-axis average lattice constant and smaller than the second a-axis average lattice constant.

9. The nitride semiconductor element according to claim 8, wherein the first a-axis average lattice constant, the a-axis in-plane lattice constant of the AlGaN layer, the a-axis average lattice constant of the reference AlGaN layer, and the second a-axis average lattice constant are monotonic increasing values.

10. The nitride semiconductor element according to claim 1, wherein the reference AlGaN layer is arranged to compress the Group III-nitride electron transfer layer in a-axis.

11. The nitride semiconductor element according to claim 1, wherein the AlGaN layer is arranged to compress the reference AlGaN layer in a-axis.

12. The nitride semiconductor element according to claim 1, wherein the AlN layer is stretched by the AlGaN layer in a-axis.

13. The nitride semiconductor element according to claim 1, wherein the primary surface of the Si substrate is a (111) plane.

14. The nitride semiconductor element according to claim 1, wherein the Group III-nitride electron transfer layer has a c-axis lattice constant which has a degree of strain that is −

0.07% or more.

15. The nitride semiconductor element according to claim 1, wherein the Group III-nitride electron transfer layer has a thickness of 500 nm to 2000 nm.

16. The nitride semiconductor element according to claim 1, wherein the Group III-nitride electron supply layer has a thickness of 500 nm to 2000 nm.

17. The nitride semiconductor element according to claim 1, wherein the AlN layer has a thickness of 50 nm to 200 nm.

18. The nitride semiconductor element according to claim 1, wherein the AlGaN layer has a thickness of 100 nm to 500 nm.

19. The nitride semiconductor element according to claim 1, wherein the reference AlGaN layer has a thickness of 100 nm to 500 nm.

20. A nitride semiconductor package, comprising:

a nitride semiconductor element according to claim 1; and

a resin package that covers the nitride semiconductor element.