Integrated circuit having transistors that include insulative punchthrough regions and method of formation

Abstract

An integrated circuit includes a plurality of transistors formed to include insulative punchthrough regions. Each of the plurality of transistors includes a channel formed upon a substrate, an insulative punchthrough region formed below the channel, a source formed upon the insulative punchthrough region residing adjacent a first end of the channel, a drain formed upon the insulative punchthrough region residing adjacent a second end of the channel, a gate oxide formed above the channel and a gate conductor formed above the gate oxide. Isolation regions may also be formed in the substrate that have an etch stop defination that was formed upon formation of the insulative punchthrough region. A voltage threshold region may be formed between the gate oxide and the channel and lightly doped regions may be formed adjacent the channel. The insulative punchthrough region may be and oxide layer formed within the substrate in an oxygen implant step that also formed the etch stop defination. The transistors and other circuit elements formed in the substrate may be interconnected to form an integrated circuit.