摘要 |
The formation of lightly doped regions under a gate of a transistor via gate autodoping is disclosed. One embodiment of the invention is a method having four steps. In the first step, a gate having two sidewalls is provided over a gate oxide over a semiconductor substrate; source and drain regions with the substrate adjacent to the sidewalls of the gate are also provided. In the second step, the gate oxide is etched to reduce the length of the gate oxide. In the third step, a spacer is formed at each sidewall of the gate to create at each side of the gate oxide an air cavity defined by the spacer, the gate, the substrate and the gate oxide. In the fourth step, a rapid thermal anneal is performed to form lightly doped regions within the substrate, as autodoped from the gate.
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