US Patent 10002939 Nanosheet transistors having thin and thick gate dielectric material

Provided is a method for forming a semiconductor structure. In embodiments, the method includes forming multiple channel nanosheets in multiple first stacks over a substrate. The channel nanosheets in the first stack define first stack cavities such that each pair of adjacent stacked channel nanosheets in the first stack is separated by one of the first stack cavities. The method further includes forming multiple channel nanosheets in a second stack over a substrate. The channel nanosheets in the second stack defining second stack cavities such that each pair of adjacent stacked channel nanosheets in the first second is separated by one of the second stack cavities. The method further includes filling the first stack cavities with a first gate dielectric material and filling the second stack cavities with a work function metal and a second gate dielectric material. The first gate dielectric material differs from the second gate dielectric material.