摘要 |
A vertical conduction MOSFET semiconductor device is formed in a non-epitaxial (float zone) lightly doped silicon substrate. Device junction regions are formed in the top surface of the lightly doped float zone substrate. The backside of the wafer is then ground by surface grinding to attain a desired thickness. Phosphorus, or another N type dopant species, is then implanted into the back surface and is activated by a laser anneal. Back surface damage caused by grinding and/or implantation is intentionally retained. Alternatively, a "transparent" layer is formed by depositing highly doped amorphous silicon on the back surface. Titanium, or another metal (excluding aluminum), is then deposited on the back surface and annealed to form a titanium silicide, or other silicide for a contact electrode.
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