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Ti/Pd/Ag Contacts to n-Type GaAs for High Current Density Devices

“…3c and Table I ) and metallization systems based on Pd/ 330 Ge on n-GaAs($3.0 9 10 À7 ). 19,21,34 Obviously, the 16 it could be used 340 with low or medium concentrator photovoltaic (CPV) 341 solar cells operating below 500 suns. Nevertheless,…”

“…15-17 Some other metal systems receiving some 83 attention over the last years include metallizations 84 based on Pd/Ge, which exploit the inward diffusion 85 of Ge and the formation of a highly doped semicon-86 ductor and/or barrier height lowering stemming 87 from the formation of a Ge-GaAs heterojunc-88 tion, [18][19][20][21] and some other similar metallization 89 systems such as Pd/Sn, Ge/Cu. 22 In summary, the 90 search of a new metal system providing (1) low 91 metal/semiconductor specific contact resistance 92 (<10 À5 X cm 2 ); (2) low metal sheet conductivity; 93 (3) high long term stability; (4) good bondability and 94 (5) low cost is still an open field of research.…”

Raman spectroscopy of Ge/Pd/GaAs contacts

“…These contacts are based on solid phase regrowth [2]; the main representative is the Pd/Ge ohmic contact. The advantage of these types of contact systems includes in many cases an excellent contact resistivity, stability, and morphology [3][4][5][6]. Various deposition schemes can be employed, e.g., Pd-GePd or Pd-Ge, but the main feature is to have the ratio Ge/Pd > 1.0 [3].…”

“…The advantage of these types of contact systems includes in many cases an excellent contact resistivity, stability, and morphology [3][4][5][6]. Various deposition schemes can be employed, e.g., Pd-GePd or Pd-Ge, but the main feature is to have the ratio Ge/Pd > 1.0 [3]. For Ge/Pd ratios less than 1, additional binary phases, such as Pd 2 Ge, PdAs 2 , and PdGa, can form which further complicate the metallurgy and create less uniform contacts.…”

“…Analyses of processes, which occur within the contact structures, are dealt with in a number of contributions [3,7,8]. Out of current analytical methods, we can name the transmission electron microscopy (TEM), Auger electron microscopy (AES), energy dispersive X-ray spectra (EDX) and numerous other methods.…”