Process for producing a large area solid state radiation detector

• US 5,254,480 A
• Filed: 02/20/1992
• Issued: 10/19/1993
• Est. Priority Date: 02/20/1992
• Status: Expired due to Term

• Current Assignee: Imation Corporation (Glassbridge Enterprises, Inc.)
• Original Assignee: 3M Company
• Inventors: Tran, Nang T.
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): TRINH, MICHAEL MANH
• Application Number:
  US07/839,268
• Time in Patent Office: 607 Days
• Field of Search: 437/2-5, 437/205, 437/208, 437/51, 437/906, 250/270.1, 250/270.9, 250/271, 250/270.14, 148/DIG. 150
• US Class Current: 438/59
• CPC Class Codes: H01L 21/8222 Bipolar technology
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/14618 Containers
• CPC Class Codes: H01L 27/14663 Indirect radiation imagers, e.g. using luminescent members
• CPC Class Codes: H01L 27/14692 Thin film technologies, e.g. amorphous, poly, micro- or nanocrystalline silicon
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10S 148/15 Silicon on sapphire SOS
• CPC Class Codes: Y10S 438/945 Special, e.g. metal

Abstract

A process for producing an array of solid state radiation detectors includes depositing on a substrate one or more layers of silicon-based materials and then depositing a metal layer overlying silicon-based substance. The metal layer is formed into an array of metal layer regions, and then the metal layer is used as a mask to remove exposed adjacent silicon-based substance layers thereby forming an array of silicon-based substance layers that are aligned with the array of metal layers for forming an array of photosensitive sensing devices. The process of the present invention reduces the number of microlithography steps that are used in forming an array of layered amorphous silicon photosensitive devices.

Claims

1. A process for producing a large area radiation detector, the process comprising:

forming submodules, each submodule including an array of thin film transistors;

positioning the submodules in side-by-side relationship;

forming a bottom electrode layer that overlies the thin film transistor arrays of the submodule;

depositing on the bottom electrode layer doped and undoped amorphous silicon layers;

forming a top electrode layer on the amorphous silicon layers;

using microlithography to form an array of top electrode regions overlying the thin film transistors of the submodules;

selectively etching the doped and undoped amorphous silicon layers using the array of top electrode regions as a mask to form an array of photosensitive devices overlying the thin film transistors

2. The process of claim 1 wherein the photosensitive device is a photodiode.

3. The process of claim 1 wherein the doped amorphous silicon layer includes a p³⁰ -type amorphous silicon layer and an n³⁰ -type amorphous silicon layer.

4. The process of claim 1 wherein the top electrode layer is made of platinum.

5. The process of claim 1 and further including forming an x-ray sensitive phosphor layer in light receiving association with the array of photosensitive devices.

6. A process for producing a large area radiation detector, the process comprising:

forming submodules, each submodule including an array of thin film transistors;

positioning the submodules in side-by-side relationship;

forming a bottom electrode layer that overlies the thin film transistor arrays of the submodules, and patterning the electrode layer using microlithography to form an array of electrodes overlying the array of transistors;

depositing a continuous layer of photoconductor on the bottom electrode layer; and

forming a top common electrode layer on the continuous layer of photoconductor.

7. The process of claim 6 wherein the top common electrode layer is made of platinum.

8. The process of claim 6 and further including forming an x-ray sensitive phosphor layer in light receiving association with the top common electrode layer.