| 摘要 |
<p>A method for the heat treatment of oxygenated and lightly doped silicon single crystals provides a conductive silicon substrate which draws off stray currents from adjacent n-channel and p-channel transistors, preventing latch-up in CMOS integrated circuits. A lightly doped oxygenated, single crystal silicon wafer (12) is heated at 1000 to 1150oC to out-diffuse oxygen from the surface layer (10). After device fabrication on this denuded surface, the wafer is heated at 450oC to generate oxygen donors in the bulk of the wafer (18) which then becomes strongly conductive or n-type. The water surface will remain lightly doped (16), either n- or p-type from the original doping. By suitable masking during the oxygen out-diffusion step, islands (22) of lightly doped p- or n-type material on the surface may be surrounded by guard rings of strongly conducting n-type material formed in the final heating step at 450oC.</p> |
