Polysilicon hard mask for enhanced alignment signal

A method of processing a substrate, comprising:

• depositing a polysilicon layer over a substrate including an alignment feature such that said polysilicon layer reaches a first temperature of less than about 550 degrees Celsius;
• annealing said substrate with said polysilicon layer to raise said polysilicon layer to a second temperature greater than or equal to about 600 degrees Celsius and to decrease an extinction coefficient of said polysilicon layer to a value of less than or equal to about 0.25;
• depositing a photoimageable layer over said polysilicon layer;
• receiving an alignment signal including light from said alignment feature through said polysilicon layer, said alignment signal having a substantial signal component at a wavelength or about 5300 angstroms;
• aligning a photolithographic exposure system with said substrate using said alignment signal from said alignment feature;
• patterning said photoimageable layer with said aligned photolithographic exposure system to form a patterned first mask layer overlying said polysilicon layer;
• selectively removing portions of said polysilicon layer exposed by said patterned first mask layer to form a patterned polysilicon mask layer;
• and
• selectively processing areas of said substrate in accordance with said patterned second mask layer.