Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors

Yuen Yee Wong; Yu Kong Chen; Jer Shen Maa; Hung Wei Yu; Yung Yi Tu; Chang Fu Dee; Chi Chin Yap; Edward Yi Chang

doi:10.1063/1.4824894

Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors

Yuen Yee Wong, Yu Kong Chen, Jer Shen Maa, Hung Wei Yu, Yung Yi Tu, Chang Fu Dee, Chi Chin Yap, Edward Yi Chang^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

Ti/Al/Ni/Cu ohmic contact for AlGaN/GaN structure has been fabricated. The Ni layer played an important role in achieving low specific contact resistance (r_c), smooth morphology, and excellent edge acuity. With a 50-Å Ni layer, a r_c of 1.35 × 10^-6 Ω-cm ² and a root-mean-square roughness of 7.65 nm have been realized. The characterization results indicated that no evidence of Cu diffusion into the semiconductor layers. The formation of Al-Cu and Ti-Cu alloys might have confined the Cu within the ohmic metal. In the absence of gold, the surface roughening caused by Au-Al alloy in conventional Ti/Al/Ni/Au structure was also prevented.

Original language	English
Article number	152104
Journal	Applied Physics Letters
Volume	103
Issue number	15
DOIs	https://doi.org/10.1063/1.4824894
State	Published - 7 Oct 2013

Access to Document

10.1063/1.4824894

Fingerprint Dive into the research topics of 'Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors'. Together they form a unique fingerprint.

Cite this

@article{1db9080a07954cdbb7851b92f81b6bdc,

title = "Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors",

abstract = "Ti/Al/Ni/Cu ohmic contact for AlGaN/GaN structure has been fabricated. The Ni layer played an important role in achieving low specific contact resistance (rc), smooth morphology, and excellent edge acuity. With a 50-{\AA} Ni layer, a rc of 1.35 × 10-6 Ω-cm 2 and a root-mean-square roughness of 7.65 nm have been realized. The characterization results indicated that no evidence of Cu diffusion into the semiconductor layers. The formation of Al-Cu and Ti-Cu alloys might have confined the Cu within the ohmic metal. In the absence of gold, the surface roughening caused by Au-Al alloy in conventional Ti/Al/Ni/Au structure was also prevented.",

author = "Wong, {Yuen Yee} and Chen, {Yu Kong} and Maa, {Jer Shen} and Yu, {Hung Wei} and Tu, {Yung Yi} and Dee, {Chang Fu} and Yap, {Chi Chin} and Chang, {Edward Yi}",

year = "2013",

month = oct,

day = "7",

doi = "10.1063/1.4824894",

language = "English",

volume = "103",

journal = "Applied Physics Letters",

issn = "0003-6951",

publisher = "American Institute of Physics",

number = "15",

}

TY - JOUR

T1 - Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors

AU - Wong, Yuen Yee

AU - Chen, Yu Kong

AU - Maa, Jer Shen

AU - Yu, Hung Wei

AU - Tu, Yung Yi

AU - Dee, Chang Fu

AU - Yap, Chi Chin

AU - Chang, Edward Yi

PY - 2013/10/7

Y1 - 2013/10/7

N2 - Ti/Al/Ni/Cu ohmic contact for AlGaN/GaN structure has been fabricated. The Ni layer played an important role in achieving low specific contact resistance (rc), smooth morphology, and excellent edge acuity. With a 50-Å Ni layer, a rc of 1.35 × 10-6 Ω-cm 2 and a root-mean-square roughness of 7.65 nm have been realized. The characterization results indicated that no evidence of Cu diffusion into the semiconductor layers. The formation of Al-Cu and Ti-Cu alloys might have confined the Cu within the ohmic metal. In the absence of gold, the surface roughening caused by Au-Al alloy in conventional Ti/Al/Ni/Au structure was also prevented.

AB - Ti/Al/Ni/Cu ohmic contact for AlGaN/GaN structure has been fabricated. The Ni layer played an important role in achieving low specific contact resistance (rc), smooth morphology, and excellent edge acuity. With a 50-Å Ni layer, a rc of 1.35 × 10-6 Ω-cm 2 and a root-mean-square roughness of 7.65 nm have been realized. The characterization results indicated that no evidence of Cu diffusion into the semiconductor layers. The formation of Al-Cu and Ti-Cu alloys might have confined the Cu within the ohmic metal. In the absence of gold, the surface roughening caused by Au-Al alloy in conventional Ti/Al/Ni/Au structure was also prevented.

UR - http://www.scopus.com/inward/record.url?scp=84886927850&partnerID=8YFLogxK

U2 - 10.1063/1.4824894

DO - 10.1063/1.4824894

M3 - Article

AN - SCOPUS:84886927850

VL - 103

JO - Applied Physics Letters

JF - Applied Physics Letters

SN - 0003-6951

IS - 15

M1 - 152104

ER -

Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors

Abstract

Access to Document

Other files and links

Cite this