Electrostatic discharge protection device and method using depletion switch

An integrated circuit device for electrostatic discharge protection, comprising:

• a semiconductor substrate;
• an insulation layer formed over the substrate;
• a lightly doped region of a first dopant type formed over the insulation layer;
• a first diffusion region of the first dopant type formed at least partially in the lightly doped region;
• a second diffusion region of the first dopant type formed at least partially in the lightly doped region and spaced apart from the first diffusion region;
• a resistive path defined by the lightly doped region, the first and the second diffusion regions;
• and
• a third diffusion region of a second dopant type formed in the lightly doped region, and disposed between and spaced apart from the first and the second diffusion regions,
• wherein the third diffusion region keeps the resistive path at a low resistive state until a normal operation period occurs.

An electrostatic discharge protection circuit, comprising

• a first terminal;
• a second terminal;
• an integrated circuit device including
• a lightly doped region of a first dopant type;
• a first diffusion region of the first dopant type formed at least partially in the lightly doped region and electrically coupled to the first terminal;
• a second diffusion region of the first dopant type formed at least partially in the lightly doped region and spaced apart from the first diffusion region and electrically coupled to the second terminal;
• and
• a third diffusion region of a second dopant type formed in the lightly doped region, and disposed between and spaced apart from the first and the second diffusion regions, the third diffusion region keeping a low resistive path between the first and second terminals until a normal operation period occurs, and
• a control circuit for inducing a depletion region in the lightly doped region as the normal operation period occurs.

A method of electrostatic discharge protection, comprising:

• providing an integrated circuit device including
• a lightly doped region of a first dopant type;
• a first diffusion region of the first dopant type formed at least partially in the lightly doped region;
• a second diffusion region of the first dopant type formed at least partially in the lightly doped region and spaced apart from the first diffusion region;
• a resistive path defined by the lightly doped region, the first and the second diffusion regions;
• and
• a third diffusion region of a second dopant type formed in the lightly doped region, and disposed between and spaced apart from the first and the second diffusion regions, the third diffusion region controlling the resistive state of the resistive path, and
• keeping the resistive path at a low resistive state until a normal operation period occurs.

A method of electrostatic discharge protection, comprising:

• forming a resistive path in a semiconductor well of a first dopant type;
• forming a diffusion region of a second dopant type in the semiconductor well to control a resistive state of the resistive path;
• and
• keeping the resistive path at a low resistive state until a normal operation period occurs.