III-nitride materials including low dislocation densities and methods associated with the same

• US 8,368,117 B2
• Filed: 03/29/2010
• Issued: 02/05/2013
• Est. Priority Date: 07/07/2004
• Status: Active Grant

• Current Assignee: MACOM Technology Solutions Holdings, Inc.
• Original Assignee: International Rectifier Corporation (Infineon Technologies AG)
• Inventors: Piner, Edwin L., Roberts, John C., Rajagopal, Pradeep
• Primary Examiner(s): MATTHEWS, COLLEEN ANN
• Application Number:
  US12/748,778
• Publication Number:
  US 20100295056A1
• Time in Patent Office: 1,044 Days
• Field of Search: 257/189, 257/200, 257/615, 257/745, 257/E31.019, 257/E27.012
• US Class Current: 257/189
• CPC Class Codes: C30B 25/02 Epitaxial-layer growth
• CPC Class Codes: C30B 29/403 AIII-nitrides
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02505 consisting of more than two layers
• CPC Class Codes: H01L 21/0251 Graded layers
• CPC Class Codes: H01L 21/02513 Microstructure
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02543 Phosphides

Abstract

Semiconductor structures including one, or more, III-nitride material regions (e.g., gallium nitride material region) and methods associated with such structures are provided. The III-nitride material region(s) advantageously have a low dislocation density and, in particular, a low screw dislocation density. In some embodiments, the presence of screw dislocations in the III-nitride material region(s) may be essentially eliminated. The presence of a strain-absorbing layer underlying the III-nitride material region(s) and/or processing conditions can contribute to achieving the low screw dislocation densities. In some embodiments, the III-nitride material region(s) having low dislocation densities include a gallium nitride material region which functions as the active region of the device. The low screw dislocation densities of the active device region (e.g., gallium nitride material region) can lead to improved properties (e.g., electrical and optical) by increasing electron transport, limiting non-radiative recombination, and increasing compositional/growth uniformity, amongst other effects.

Claims

1. A semiconductor structure comprising:

a III-nitride material region having a screw dislocation density of less than about 10⁸/cm² throughout the entire volume of the III-nitride material region and having an edge dislocation density of greater than about 10⁸/cm².

2. The structure of claim 1, wherein the III-nitride material region is a gallium nitride material region.

3. The structure of claim 1, wherein the III-nitride material region is free-standing.

4. The structure of claim 1, wherein the III-nitride material region is substantially planar.

5. The structure of claim 1, wherein the III-nitride material region is vertically-grown.

6. The structure of claim 1, wherein the III-nitride material region extends continuously across an underlying region.