Patent ID: 8536555

Claim:
A method of forming a voltage sensitive resistor (VSR) read only memory (ROM) device on a semiconductor substrate having a semiconductor device, the method comprising the steps of: forming a VSR in electrical contact with the semiconductor device comprising: forming a layer of insulation on the semiconductor device; forming an opening in the insulation, the opening aligned with the semiconductor device; depositing a layer of physically deposited elemental titanium in the opening; depositing on the elemental titanium by chemical vapor deposition a first titanium nitride layer having residual titanium-carbon bonding such that the VSR is resistive as formed and can become less resistive by at least an order of 10 2 when a predetermined voltage and current are applied to the VSR; depositing on the first titanium nitride layer by chemical vapor deposition a second titanium nitride layer having residual titanium-carbon bonding such that the VSR is resistive as formed and can become less resistive by at least an order of 10 2 when a predetermined voltage and current are applied to the VSR; treating the second titanium nitride layer to substantially remove the titanium-carbon bonding; and depositing a metallic layer in contact with the second titanium nitride layer; wherein the VSR in electrical contact with the semiconductor device forms a VSR ROM device and wherein the VSR ROM device is a write once read only memory (WO ROM) device.