Method of fabricating dual-band type-II superlattice detectors based on p-B-p design

摘要

A dual-band infrared detector structure based on Type-II superlattices (T2SL) has been developed and experimentally validated. The structure according to the principles of the present invention is designed for a single Indium bump architecture and utilizes a T2SL barrier design that omits the traditional p-n junction region. The barrier design comprises multiple periods where each period comprises multiple monolayers doped P type. By selecting the composition, number of monolayers per period and number of periods, a transition region is created in the conduction band between a first absorber layer and a second absorber layer that allows operation at low biases (<100 mV for both bands) and exhibits a dark current density in the longer wavelength band comparable to that obtained with single-color detectors.

主权项

1. A method of making a Type II Superlattice Dual Band Photodetector comprising the steps of:
receiving a substrate and disposing an etch stop layer on the substrate; disposing a first contact layer on the etch stop layer; disposing a first absorber layer on the first contact layer; disposing a Type II Super Lattice (T2SL) barrier layer on the first absorber layer; wherein the barrier layer comprises a plurality of monolayers;
the plurality of monolayers comprise repeating sets of monolayers of a first type, a second type and third type, wherein the first type of monolayer comprises AlSb, the second type of monolayer comprises InSb and the third type of monolayer comprises InAs; disposing a second absorber layer on the barrier layer; disposing a second contact layer on the second absorber layer.