Abstract
A process method of ion sensitive field effective transistor is disclosed. The steps of the process mentioned above comprises as follow. Firstly, providing a field enhancement transistor, and at least one metal layer and at least one inter-connection layer are covered on a gate of the field enhancement transistor. The surface of the top of the metal layer is revealed on the air. Secondary, eliminating the metal layer and the inter-connection layer to reveal the poly gate on the air. Finally, eliminating the poly gate, and reveal a gate oxide on the air.