Sidewall spacer formation process

Sidewall spacers are formed alongside the polygates to prevent the high-dose dopants used in the S/D implant step from penetrating too close to the channel where S/D punch-through could occur. The sidewall spacer formation process comprises two major process steps. These include the deposition of a CVD oxide layer across the surface of the wafer, followed by etching back of this... 

Figure 16.13 Process sequence for the sidewall spacer formation (a) spacer oxide deposition and (b) spacer oxide etch back.

Figure 17.19 Process sequence for self-aligned double-patterning technique by means of sidewall spacer formation.

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