Patent ID: 6610361
Filing Date: 2003-08-26
Classification: C23C,H01L,Y10T

Abstract:
A method for producing a multi-layer assembly of polysilicon thin films, said assembly having a predetermined overall bending moment, said method comprising:providing a substrate; forming a first polysilicon thin film layer on said substrate such that said first layer has a devitrified microstructure and an internal tensile stress, a first thickness and a first location within said assembly to result in a first moment, said first layer formed by chemical vapor deposition of silane at a temperature of from about 550Â° C. to about 590Â° C.; forming a second polysilicon thin film layer on said first layer such that said second layer has a predominantly columnar microstructure and an internal compressive stress, a second thickness and a second location within said assembly to result in a second moment, said second layer formed by chemical vapor deposition of silane at a temperature of from about 600Â° C. to about 700Â° C.; and forming successive polysilicon thin film layers on said first and second layers such that each successive layer (i) has either a devitrified microstructure and an internal tensile stress formed by chemical vapor deposition of silane at a temperature of from about 550Â° C. to about 590Â° C., or a predominantly columnar microstructure and an internal compressive stress formed by chemical vapor deposition of silane at a temperature of from about 600Â° C. to about 700Â° C., (ii) has a microstructure that is different than the microstructure of an adjacent layer, and (iii) has a thickness and is disposed at a location in said multi-layer assembly such that said successive layer has a moment that when summed with said first moment, said second moment, and any other moments from said successive layers, results in said predetermined overall bending moment of said multi-layer assembly.