Adhesion studies of GaAs-based ohmic contact and bond pad metallization

Conference · Fri Mar 01 04:00:00 EST 1996

OSTI ID:210932

Seigal, P K; Briggs, R D; Rieger, D J; Baca, A G ^[1]; Howard, A J ^[2]

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1. Sandia National Labs., Albuquerque, NM (United States)
2. Intel Corp., Rio Rancho, NM (United States)

Adhesion strength and surface morphology of commonly used n- and p-type ohmic contacts and pad metallization schemes for GaAs were investigated. GeNiAu, GePdAu, BeAu, and TiPtAu (being studied as potential ohmic contacts for internal optoelectronic devices) had quantitiative measurements made using wire bond pull testing to determine adhesion. Bond pad metals deposited as evaporated TiAu, TiPtAu, and 2-5 micron thick electroplated Au deposited on both semi-insulating GaAs and on Si{sub 3}N{sub 4}/GaAs were evaluated independently from the ohmic contact metals. In all samples was observed a strong correlation between surface treatment, surface morphology, wire bondability, and bond strength. Very high bond strengths (pull test average values above 6.5 grams force with 25 micron dia Au wire) wereobtained for n-type, p-type, and bond pad metals. Average values of 8.0 gram force were achieved with two-step GeAu/NiAu/TiPtAu metallization, while one-step deposition yielded poorer values. Adhesion was also monitored after aging at 250 C in air for four different times up to 60 hr by wire bond pull testing, with little degradation occurring.

• Research Organization: Sandia National Labs., Albuquerque, NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 210932
• Report Number(s): SAND--95-2117C; CONF-960457--1; ON: DE96008229
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
ADHESION
ELECTRIC CONTACTS
ELECTRO-OPTICAL EFFECTS
GALLIUM ARSENIDES
N-TYPE CONDUCTORS
P-TYPE CONDUCTORS