HgCdTe long-wavelength infrared photovoltaic detectors formed by reactive ion etching

Reactive ion etching (RIE) is known to type convert p-type HgCdTe to n-type, thus providing a method for p-n junction formation for photodiode fabrication. Mid-wavelength infrared (MWIR) n-on-p photodiodes fabricated using RIE induced p-to-n type conversion have already been demonstrated and show excellent performance. This paper will report on the successful application of RIE junction formation technology for long-wavelength infrared (LWIR) HgCdTe photodiodes, and compares the device performance of photodiodes fabricated on vacancy and extrinsically doped p-type HgCdTe. The diode current versus bias voltage (I-V) characteristic of these devices have also been measured as a function of temperature in the range 20K to 200K with various junction areas. These results are compared in the light of detailed Hall measurement data obtained from type converted materials.