Low dark current high performance Hg 0.57 Cd 0.43 Te infrared detector advancements with ion implantation

This paper presents the infrared detector performance improvement accomplishments by Raytheon Vision Systems (RVS) and by AVYD Devices Inc (AVYD). The RVS-AVYD collaboration has resulted in the demonstration of very large imaging focal plane arrays with respectable operability and performance which could potentially be useful in a variety of promising new applications to advance performance capability for future near and short wave infrared imaging missions. This detector design concept potentially permits ultra-small pixel large format imaging capabilities for diffraction limited resolution down to 5μm pitch focal planes. In this paper, we report on the work performed at the RVS's advanced prototype engineering facility, to fabricate planar detector array wafers with a combination of RVS's Hg1-xCdxTe production material growth and detector fabrication processes and AVYD's p-type ion-implantation process. This paper will review the performance of a 20μm pitch 1,024 x 1,024 format SWIR focal plane array. The detector array was fabricated in Hg1-xCdxTe material responsive from near-infrared to 2.5μm cutoff wavelength. Imaging capability was achieved via interconnect bump bond connection of this detector array to an RVS astronomy grade readout chip. These focal plane arrays have exhibited outstanding quantum efficiency uniformity and magnitude over the entire spectral range and in addition, have also exhibited very low leakage current with median values of 0.25 electrons per second. Detector arrays were processed in engineering grade Hg1-xCdxTe epitaxial layers grown with a modified liquid phase epitaxy process on CdZnTe substrates followed by a combination of passivation/ion implantation/passivation steps. This paper will review the detector performance data in detail including the test structure current-voltage plots, spectral cutoff curves, FPA quantum efficiency, and leakage current.