A study of p-type ohmic contacts to InAlAs/InGaAs heterostructures
- Sandia National Labs., Albuquerque, NM (United States). Center for Compound Semiconductor Technology
Optical modulators operating at near-infrared wavelengths are of interest for a variety of applications including bidirectional communications and optical interconnects. The fabrication of 1.06 {micro}m and 1.32 {micro}m operating wavelength strained-layer-superlattice vertical-cavity optoelectronic modulators requires the formation of a p-type ohmic contact to the InAlAs/InGaAs quarter-wave bottom mirror stack. In this study, BeAu and TiPtAu p-type ohmic contact metallization schemes were evaluated for use on molecular beam epitaxy (MBE) grown In{sub .10}Al{sub .90}As/In{sub .12}Ga{sub .88}As and In{sub .32}Al{sub .68}As/In{sub .33}Ga{sub .67}As device heterostructures. Recessed and nonrecessed transmission line measurement (TLM) structures were fabricated and evaluated as a function of rapid thermal anneal (RTA) temperatures over the range of 360 C--420 C. Atomic force microscopy (AFM) was used to determine the surface morphology of each sample for evidence of metal or material degradation. For contacts directly on InGaAs layers, TiPtAu contacts had relatively high specific contact resistance values of {rho}{sub c} {approximately} 3 {times} 10{sup {minus}4} {Omega}cm{sup 2} and displayed no dependence on the anneal. The BeAu contacts had minimum specific contact resistance values of {rho}{sub c} {approximately} 5 {times} 10{sup {minus}7} {Omega}cm{sup 2} but showed evidence of degradation at higher temperatures. Contacts directly made to InAlAs layers had minimum specific contact resistances of {rho}{sub c} {approximately} 4 {times} 10{sup {minus}5} {Omega}cm{sup 2} and were improved slightly with the addition of a thin GaAs layer.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 212554
- Report Number(s):
- SAND-95-2217C; CONF-960457-4; ON: DE96008869; TRN: AHC29608%%99
- Resource Relation:
- Conference: ICMCTF `96: international conference on metallurgical coatings and thin films, San Diego, CA (United States), 22-26 Apr 1996; Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ELECTRIC CONTACTS
PERFORMANCE
HETEROJUNCTIONS
INDIUM ARSENIDES
ALUMINIUM ARSENIDES
GALLIUM ARSENIDES
P-TYPE CONDUCTORS
BERYLLIUM ALLOYS
GOLD ALLOYS
TITANIUM ALLOYS
PLATINUM ALLOYS
SEMICONDUCTOR DEVICES
ELECTRIC CONDUCTIVITY
SUPERLATTICES
EXPERIMENTAL DATA