Effect of Substrate on “On‐Resistance” of a Power Metal‐Oxide Semiconductor Field‐Effect Transistor Device

Abstract

The on‐resistance of a power metal‐oxide semiconductor field‐effect transistor device was found to differ dramatically based on substrate supplier. Differences in substrate resistance could not account for the observed change in the total device on‐resistance, . Other possible factors, bulk microdefects generated by oxygen precipitation and drain contact resistance, could affect the observed difference in and were investigated accordingly. Substrates from three different suppliers with and without the addition of a 2 h, 700°C precipitation nucleation heat cycle were compared. The difference in bulk microdefect densities between the substrates could not account for the observed change in . By adding an aluminum backmetal layer prior to the deposition of the TiNiAg backmetal, was decreased regardless of the prebackmetal cleaning process. This revealed that the effect of substrate resistivity on the contact resistance of backmetal was the dominant cause of discrepancies between the substrates. © 1999 The Electrochemical Society. All rights reserved.