METHOD TO MANUFACTURE DOUBLE-POLY CAPACITORS

摘要

A method a manufacturing integrated circuits including transistors, capacitors, and resistors, comprises the steps of forming a first poly layer, which is heavily doped; forming a dielectric layer over the first poly layer; forming a second poly layer over the dielectric layer, the second poly layer being lightly doped; and subsequently further doping the second poly layer at least in capacitor regions while masking the second poly layer in resistor regions so as to heavily dope the second poly layer in the capacitor regions and thereby improve capacitor linearity while substantially maintaining the resistivity of the lightly doped second poly layer in the resistor regions. In this way capacitors having good linearity can be fabricated at the same time as small area resistors with good contact resistance.