Influence of processing conditions on the titanium–aluminum contact metallization on a silicon wafer for thermal management

Abstract

There is a growing need for digital and power electronics to deliver higher power for applications in batteries for electric vehicles, energy sources from wind and solar, data centers, and microwave devices. The higher power also generates more heat, which requires better thermal management. Diamond thin films and substrates are attractive for thermal management applications in power electronics because of their high thermal conductivity. However, deposition of diamond by microwave plasma enhanced chemical vapor deposition (MPECVD) requires high temperatures, which can degrade metallization used in power electronic devices. In this research, titanium (Ti)–aluminum (Al) thin films were deposited by DC magnetron sputtering on p-type Si (100) substrates using a physical mask for creating dot patterns for measuring the properties of the contact metallization. The influence of processing conditions and postdeposition annealing in argon (Ar) and hydrogen (H2) at 380 °C for 1 h on the properties of the contact metallization is studied by measuring the I-V characteristics and Hall effect. The results indicated a nonlinear response for the as-deposited films and linear ohmic contact resistance after postannealing treatments. In addition, the results on contact resistance, resistivity, carrier concentration, and Hall mobility of wafers extracted from Ti–Al metal contact to Si (100) are presented and discussed.