Method of monitoring power supplied to heat a substrate

A method for forming a crystalline semiconductor material comprising:

• forming an amorphous semiconductor material upon a substrate;
• maintaining said amorphous semiconductor material upon said substrate at a desired temperature by delivering power from a variable supply of power to a heating element to heat said amorphous semiconductor material upon said substrate;
• monitoring the power delivered by the variable supply of power to the heating element;
• and
• terminating the delivery of power from said variable supply of power to the heating element in response to a reduction in the power delivered by the variable supply of power to the heating element, wherein said amorphous semiconducton material upon the substrate is converted to a crystalline semiconductor material at said reduction in power.

A method for forming polysilicon comprising:

• forming amorphous silicon upon a substrate;
• maintaining said amorphous silicon upon said substrate at a desired temperature by delivering power from a variable supply of power to a heating element to heat said amorphous silicon upon said substrate;
• monitoring the power delivered by the variable supply of power to the heating element;
• and
• terminating the delivery of power from said variable supply of power to the heating element in response to a reduction in the power delivered by the variable supply of power to the heating element, wherein said amorphous silicon upon the substrate is converted to polysilicon at said reduction in power.

A method for foaming a crystalline Si/Ge alloy comprising:

• forming an amorphous Si/Ge alloy upon a substrate;
• maintaining said amorphous Si/Ge alloy upon said substrate at a desired temperature by delivering power from a variable supply of power to a heating element to heat said amorphous Si/Ge alloy upon said substrate;
• monitoring the power delivered by the variable supply of power to the heating element;
• and
• terminating the delivery of power from said variable supply of power to the heating element in response to a reduction in the power delivered by the variable supply of power to the heating element, wherein said amorphous Si/Ge alloy upon the substrate is converted to a crystalline Si/Ge alloy at said reduction in power.

A method for monitoring power supplied to a substrate, the method comprising:

• providing a substrate in thermal communication with a heating element;
• forming amorphous silicon upon the substrate;
• delivering power from a variable supply of power to said heating element to heat said amorphous silicon upon said substrate to a desired temperature;
• monitoring the power that is delivered from said variable supply of power to said heating element;
• and
• terminating the delivery of power from said variable supply of power to the heating element in response to a reduction in the power that is delivered from said variable supply of power to said heating element, wherein said amorphous silicon has a change in surface roughness at said reduction in the power that is delivered to the heating element.