Patent ID: 8647945

Claim:
A method of forming a semiconductor device comprising: providing a material stack comprising an epitaxially grown semiconductor layer on a base semiconductor layer, a dielectric layer on the epitaxially grown semiconductor layer, and an upper semiconductor layer present on the dielectric layer; forming an etch mask on an upper surface of the upper semiconductor layer, wherein the etch mask comprises a contact opening, an isolation opening and a capacitor opening; etching a contact trench into contact with the base semiconductor layer, an isolation trench into contact with the base semiconductor layer, and a capacitor trench having a base portion present in the epitaxially grown semiconductor layer; forming a conformal dielectric layer on the contact trench, the isolation trench and the capacitor trench; removing the conformal dielectric layer from a base portion of the contact trench, wherein said removing the conformal dielectric layer comprises forming a block mask over the isolation trench and the capacitor trench, and removing an exposed portion of the conformal dielectric layer that is present at the base portion of the contact trench using an anisotropic etch, wherein the conformal dielectric layer at base portions of the capacitor trench and the isolation trench remain; forming a dopant region in the base semiconductor layer at the base portion of the contact trench; and filling the contact trench, the isolation trench and the capacitor trench with a conductive material.