Patent ID: 9735304
Date: 2017-08-15
CPC Classifications: G02B,H01L

Claim:
1. A monolithic photo detector device comprising: a photo detector disposed in or on a bulk substrate including: a first doped impurity region disposed in or on a major surface of the bulk substrate and extending along a first direction in or on the major surface of the bulk substrate, wherein the doped impurity region is adapted to receive a first voltage; a gate including a first gate portion and a second gate portion, each gate portion being (i) spaced apart from the other and (ii) spaced from and extending in the first direction over the major surface of the bulk substrate, wherein the gate is adapted to receive a second voltage, and wherein the doped impurity region is laterally disposed between the first and second gate portions along the first direction; a second doped impurity region, disposed in or on the major surface of the bulk substrate and extending along the first direction in or on the major surface of the bulk substrate, wherein the second doped impurity region is adapted to receive a third voltage; and a light absorbing region disposed in or on the major surface of the bulk substrate, wherein the light absorbing region includes at least one material in which, in response to light incident thereon, carrier pairs are generated, each carrier pair including a first type carrier and a second type carrier, and wherein the light absorbing region is laterally disposed between the second doped impurity region and the first gate portion of the gate; and control circuitry, disposed in or on the bulk substrate and coupled to the photo detector, to generate a plurality of voltages, including the first, second and third voltages that control an operating state of the photo detector, wherein a voltage difference between the first and third voltages is a temporal pulse, and wherein the control circuitry generates the first, second and third voltages, having relative amplitudes, so that the photo detector is in a detect state wherein the photo detector is forward biased and, in response to light incident on the light absorbing region of the photo diode, the first doped impurity region attracts the first type carriers of the carrier pairs, and the second doped impurity region attracts the second type carriers of the carrier pairs.