US 5,846,850 AGranted

Double sided interdiffusion process and structure for a double layer heterojunction focal plane array

AssigneeRaytheon TI Systems, Inc.

InventorsPeter D. Dreiske, Chang-Feng Wan

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Abstract

This invention relates to a process and structure for performing a high temperature or other process on both sides of a thin slice of material or die prior to being placed onto a integrated circuit or multi-chip module. In a particular embodiment, a process and structure is given to provide for double sided interdiffusion for passivation of a Mercury Cadmium Telluride (MCT) film which is mounted to a read-out integrated circuit (ROIC) face side up in order to fabricate vertically integrated Focal Plane Arrays (FPAs) with reduced dark currents and improved performance. The process of the present invention also allows for the insertion of novel materials such as Double Layer Heterojunction (DLHJ), MBE, MOCVD, etc. in the vertical integrated approach to FPAs.

Claims10

Dependent claims

A method of forming a focal plane array structure, said method comprising steps:

(a) depositing a mercury cadmium telluride (MCT) layer outwardly of a first carrier material;
(b) depositing a first passivation layer outwardly of said MCT layer from said first carrier material;
(c) mounting a second carrier material outwardly of said first passivation layer from said first carrier material;
(d) removing said first carrier material;
(e) depositing a second passivation layer outwardly of said MCT layer from said first passivation layer such that said MCT layer is sandwiched between said first and said second passivation layers;
(f) interdiffusing said first and second passivation layers with said MCT layer before mounting said sandwiched MCT layer to a readout integrated circuit;
(g) using said second carrier material to mount said sandwiched MCT to said readout integrated circuit with said second passivation layer facing said readout integrated circuit;
and
(h) removing said second carrier material from said sandwiched MCT such that said sandwiched MCT remains on said readout integrated circuit.

6 more elements

Dependencies are inferred from the claim text.