Patent ID: 7217604

Claim:
A method of forming a semiconductor device, comprising: providing a substrate having a first insulative layer on a surface of the substrate, and a device layer on a surface of the first insulative layer; forming an opening within the substrate in direct mechanical contact with the first insulative layer in a first region and a second region of the device, wherein the second region of the device is non-adjacent to the first region, leaving the substrate in direct mechanical contact with the first insulative layer in a third region of the device; depositing a second insulative layer over a surface of the device, filling the opening within the substrate in the first and second regions of the device, such that a thickness of the first insulative layer and the second insulative layer within the first and second regions of the device is greater than a thickness of the first insulative layer within the third region of the device; planarizing a surface of the device to remove excess insulative material; and forming an active region of the device within the device layer wherein the active region of the device comprises a source within the first region of the device, a drain within the second region of the device and a channel within the third region of the device.