Ge-rich Co-Ge contacts to n-type GaAs

TY - JOUR

T1 - Ge-rich Co-Ge contacts to n-type GaAs

AU - Koltin, E.

AU - Eizenberg, M.

PY - 1992

Y1 - 1992

N2 - Interfacial reactions for the Co/Ge and Ge/Co contact systems on (001)-oriented n-type GaAs substrates were studied with emphasis on Ge-rich stoichiometries-Co:Ge=1:1 and 2:3. Following annealing at temperatures up to 350°C, intermetallic compounds of cobalt and germanium were formed, depending on the Co:Ge atomic ratio, while the inner interface with the GaAs substrate remained intact. At higher temperatures (up to 600°C, the highest temperature used) a limited reaction with the GaAs substrate was detected. This reaction for both configurations was contained near the interface with the substrate, and did not develop with temperature. The extent of reaction decreased with the decrease in the Co:Ge atomic ratio. No reaction could be detected at the GaAs interface when the Co:Ge atomic ratio was 2:3 even at temperatures as high as 600°C (for 30 min). Contacts produced in these systems were rectifying with a nearly ideal thermionic emission behavior. This is in contrast to a case of a more Co-rich composition previously studied in our laboratory where contacts with low barriers and extensive interfacial reactions were observed after annealing at 400°C or higher temperatures.

AB - Interfacial reactions for the Co/Ge and Ge/Co contact systems on (001)-oriented n-type GaAs substrates were studied with emphasis on Ge-rich stoichiometries-Co:Ge=1:1 and 2:3. Following annealing at temperatures up to 350°C, intermetallic compounds of cobalt and germanium were formed, depending on the Co:Ge atomic ratio, while the inner interface with the GaAs substrate remained intact. At higher temperatures (up to 600°C, the highest temperature used) a limited reaction with the GaAs substrate was detected. This reaction for both configurations was contained near the interface with the substrate, and did not develop with temperature. The extent of reaction decreased with the decrease in the Co:Ge atomic ratio. No reaction could be detected at the GaAs interface when the Co:Ge atomic ratio was 2:3 even at temperatures as high as 600°C (for 30 min). Contacts produced in these systems were rectifying with a nearly ideal thermionic emission behavior. This is in contrast to a case of a more Co-rich composition previously studied in our laboratory where contacts with low barriers and extensive interfacial reactions were observed after annealing at 400°C or higher temperatures.

UR - http://www.scopus.com/inward/record.url?scp=0342311071&partnerID=8YFLogxK

U2 - 10.1063/1.350760

DO - 10.1063/1.350760

M3 - 文章

AN - SCOPUS:0342311071

SN - 0021-8979

VL - 71

SP - 4604

EP - 4611

JO - Journal of Applied Physics

JF - Journal of Applied Physics

IS - 9

ER -