Thin film transistors and their manufacture

Abstract

A method of manufacturing a bottom gate transistor comprises depositing a first microcrystalline silicon layer (40) over the gate insulator layer (22a) and exposing the microcrystalline silicon layer to a nitrogen plasma (42), thereby forming silicon nitride with a crystalline structure. A plurality of microcrystalline silicon nitride layers are formed in this way. A further microcrystalline silicon layer is deposited over the exposed layers defining the semiconductor body (14) of the transistor. This method enables the bottom of the transistor body to have a microcrystalline structure, improving the mobility of the semiconductor layer, even at the interface with the gate insulator layer. The exposed silicon nitride layers become part of the gate insulator layer, and there is improved structural matching between the gate insulator layer and the semiconductor transistor body, which layers derive from the same microcrystalline silicon structure.

Dependencies are inferred from the claim text.