Patent ID: 7002156

Claim:
A detection system for detecting gamma rays, the detection system comprising: a scintillator crystal for receiving at least one gamma ray and generating at least one ultraviolet ray; an avalanche photodiode for detecting the ultraviolet ray wherein the avalanche photodiode comprises: a substrate having a first dopant; a first layer having the first dopant, positioned on top of the substrate; a second layer having a second dopant, positioned on top of the first layer; a third layer having a second dopant, positioned on top of the second layer; a passivation layer for providing electrical passivation on a surface of the avalanche photodiode; a phosphorous silicate glass layer for limiting mobile ion transport, positioned on top of the third layer; and a pair of metal electrodes for providing an ohmic contact wherein a first electrode is positioned below the substrate and a second electrode is positioned above the third layer; wherein the avalanche photodiode comprises a first sidewall and a second sidewall forming a sloped mesa shape; and wherein the avalanche photodiode operates in an environment comprising a temperature approximately equal to 150 degrees Celsius; and a lens structure for focusing the ultraviolet ray from the scintillator crystal to the avalanche photodiode.