Patent ID: 7902049
Filing Date: 2011-03-08
Classification: C23C,H01L,Y02E,Y02P

Abstract:
1. A method for the plasma deposition of a layer of a microcrystalline semiconductor material, said method comprising the steps of: providing a deposition chamber; providing a process gas mixture which includes a precursor of a semiconductor material and a concentration of a diluent; disposing a substrate in the deposition chamber; introducing the process gas into the deposition chamber; energizing the process gas in the chamber with electromagnetic energy so as to create a plasma therefrom which decomposes at least some of the components of the process gas so as to deposit a layer of said semiconductor material onto the substrate; controlling at least one deposition parameter of said deposition process so that the layer of semiconductor material which is deposited onto the substrate in said deposition process is microcrystalline, and is deposited under a set of deposition parameters which are near, but above, the amorphous/microcrystalline threshold, said at least one parameter being selected from the group consisting of: the composition of the process gas; the pressure of the process gas; the power density of the electromagnetic energy; the frequency of the electromagnetic energy; and the temperature of the substrate; and varying the concentration of said diluent in said process gas as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited onto said substrate so as to maintain said set of deposition parameters near, but above said amorphous/microcrystalline threshold and thereby advantageously control the morphology of the microcrystalline material.