Patent ID: 6306720
Filing Date: 2001-10-23
Classification: H01L

Abstract:
A method for forming a capacitor of a mixed-mode device, comprising the steps of:providing a substrate;forming a first trench in a first area and a plurality of second trenches different from the first area in the substrate, wherein the first trench is used for isolation and the second trenches are used to form a capacitor;forming a liner oxide layer on the substrate exposed within the first trench and the second trenches;forming a dielectric layer to fill the first trench and the second trenches;forming a mask layer over the substrate and the first trench, wherein the second trenches are exposed by the mask layer;removing the liner oxide layer and the dielectric layer exposed by the mask layer;performing a first ion implantation to form a first conductive region in the substrate around the second trenches;removing the mask layer;forming a gate oxide layer over the substrate;forming a conductive layer over and filling the second trenches; andperforming a second ion implantation to form a second conductive region in the substrate around the conductive layer, wherein the second conductive region electrically connects to the first conductive region and an external power source.