Development of Spectroscopic Imaging Arrays Using Epitaxially Grown Thick Single Crystal CdTe Layers on Si Substrates

We present the design and fabrication of a 2D monolithic pixelated detector array using metalorganic vapor-phase epitaxy grown thick CdTe epitaxial layers on Si substrates. Each pixel in the array consists of a p-CdTe/n-CdTe/n⁺-Si heterojunction diode structure, and pixels were patterned by cutting deep vertical grooves using a dicing saw. We also developed a low-temperature conductive-epoxy based bonding technique to bond the array to the read out electronic circuit via an interface board. Preliminary evaluation shows that the fabricated array is capable of discriminating energies of the incident radiation and can be applied for the energy discriminating imaging purpose. Moreover, this fabrication technique is useful in developing larger imaging arrays.