Lateral high-voltage junction device
AssigneeLattice Semiconductor Corporation
InventorStewart Logie
Life of this patent
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Abstract
A lateral high-voltage junction device for over-voltage protection of an MOS circuit includes a substrate having a first junction region separated from a second junction region by a substrate region. An MOS gate electrode overlies the substrate region and is separated therefrom by a gate dielectric layer. Sidewall spacers reside adjacent to opposing sides of the MOS gate electrode and overlie the substrate region. The substrate region is defined by a junction-free semiconductor region between the first and second junction regions. An input protection circuit employs the lateral high-voltage junction device to transfer voltage transients to a ground node.
Claims5
An input protection circuit comprising:
- a voltage supply node and a ground node;
- an MOS circuit coupled to the voltage supply node and to the ground node;
- a transistor coupled to the voltage supply node and to the ground node in parallel with the MOS circuit and having a first junction region coupled to the voltage supply node, a second junction region coupled to the ground node, a junction-free substrate region between the first and second junction regions, an MOS gate electrode overlying the substrate region and separated therefrom by a gate oxide layer, and dielectric sidewall spacers adjacent to opposing sides of the MOS gate electrode and overlying the junction-free substrate region;
- a compensating diode coupled to the voltage supply node and to the ground node in parallel with the MOS circuit and the transistor;
- and
- wherein the second junction region and the substrate region comprise a semiconductor material of the same conductivity type.
A circuit comprising:
- an MOS circuit coupled to a voltage supply node and a ground node;
- a lateral high-voltage junction device for over voltage protection of the MOS circuit, the device coupled to the voltage supply and ground node in parallel with the MOS circuit, the device comprising:
- a substrate having a first junction region separated from a second junction region by a uniformly doped substrate region extending from the first junction region to the second junction region;
- an MOS gate electrode overlying the uniformly doped substrate region and separated therefrom by a gate oxide layer;
- and
- dielectric sidewall spacers adjacent to opposing sides of the MOS gate electrode and overlying the uniformly doped substrate region;
- and
- a compensating diode coupled to the voltage supply and ground node in parallel with the MOS circuit and the lateral high-voltage junction device.
Dependencies are inferred from the claim text.