Process to Ensure Breakdown Reliability of Refractory Metal Gate MOSFET After Reoxidation in Wet Forming Gas or Hydrogen
Original Publication Date: 1988-Mar-01
Included in the Prior Art Database: 2005-Feb-14
A technique is described whereby the fabrication process of refractory metal oxide silicon field-effect transistors (MOSFETs) is improved through the use of a silicon cap. The introduction of the silicon cap is designed to prevent under-the-gate SiO2 growth during refractory metal gate re-oxidation in wet forming gas or hydrogen. The cap ensures breakdown reliability of submicron gate structures. (Image Omitted) As dimensions of MOSFET devices become smaller, non-scaling effects become more important since they arise from the inability to scale certain physical parameters of the materials used to fabricate the structures. One non-scaling effect is the resistivity of the gate and interconnect metals. Another is the work function of the gate electrode on the silicon.