Effects of aluminum films deposited by RF diode sputtering in hydrogen and argon mixed gases have been investigated in n-channel silicon-gate MOS transistors and capacitors. Positive fixed oxide charge Qoxand acceptor-type surface states Nsscreated by the sputter metallization process have been confirmed experimentally. The threshold voltage Vthof a transistor metallized with aluminum sputtered in pure argon was found to be shifted toward positive voltages and its transconductance was markedly lowered due to acceptor-type surface states. Hydrogen mixing in the sputtering argon gas minimizes Qoxand Nss, resulting in small Vthand gmchanges.
No takes yet. Share an insight, caveat, or question.
Serikawa et al. (1981) studied this question.