Very high speed photodetector system using a PIN photodiode array for position sensing

• US 6,952,003 B2
• Filed: 08/05/2004
• Issued: 10/04/2005
• Est. Priority Date: 06/04/2002
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Skurnik, David, Sprague, Randall Brian, Jones, Geoffrey Hugh, Law, Waisiu, Abbott, Eric Charles
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): Lee, Patrick J.
• Application Number:
  US10/913,974
• Publication Number:
  US 20050006564A1
• Time in Patent Office: 425 Days
• Field of Search: 250/208.2, 250/206.1, 250/214.R, 327/514, 356/213, 356/218, 257/443, 257/458
• US Class Current: 250/208.2
• CPC Class Codes: H01L 21/823807 with a particular manufacturing method of the channel structures, e.g. channel implants, halo or pocket implants, or channel materials
• CPC Class Codes: H01L 21/823878 isolation region manufacturing related aspects, e.g. to avoid interaction of isolation region with adjacent structure
• CPC Class Codes: H01L 27/0922 Combination of complementary transistors having a different structure, e.g. stacked CMOS, high-voltage and low-voltage CMOS
• CPC Class Codes: H01L 27/1446 in a repetitive configuration
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/7843 the means being an applied insulating layer
• CPC Class Codes: H01L 29/7846 the means being located in the lateral device isolation region, e.g. STI

Abstract

An apparatus for detecting a centroid of a spot produced by electromagnetic radiation, e.g., optic radiation, using an array of PIN photodiodes serving as photodetectors and being organized in columns and in rows. Vertical connections are used to interconnect the PIN photodiodes in the columns in accordance with a first pattern that interconnects two or more adjacent columns. Horizontal connections are used to interconnect PIN photodiodes in the rows in accordance with a second pattern that interconnects two or more adjacent rows. The first and second patterns of interconnections can include just two adjacent columns and two adjacent rows, respectively and form a checkerboard interconnect pattern. The interconnections are made such that there are no anode connections between the PIN photodiodes in the rows and columns. The apparatus has a processing circuitry for rapidly deriving an X-extent of the centroid from current signals obtained from the columns and a Y-extent of the centroid from current signals obtained from the rows.

Claims

1. An apparatus, comprising:

an array of PIN photodiodes arranged in columns and rows on which electromagnetic radiation is to be directed producing a spot having a centroid;

vertical connections to interconnect the PIN photodiodes in the columns in a first pattern interconnecting at least two adjacent columns;

horizontal connections to interconnect the PIN photodiodes in the rows in a second pattern interconnecting at least two adjacent rows without an anode connection between the rows and columns; and

processing circuitry coupled to the array of PIN photodiodes to derive an X-extent of the centroid from the columns and a Y-extent of the centroid from the rows.

2. The apparatus of claim 1 wherein the first and second patterns are arranged in a checkerboard interconnection pattern.

3. The apparatus of claim 2 wherein the processing circuitry includes a multiplexing circuit to multiplex a number of the columns and of the rows.

4. The apparatus of claim 3 wherein the processing circuitry further includes a discrimination circuit to select the number of the columns and of the rows according to an illumination level.

5. The apparatus of claim 4 wherein the processing circuitry further includes a logic to measure the X-extent and the Y-extent from the columns and the rows and then to determine an X-coordinate and a Y-coordinate of the centroid from the number of the columns and the rows.

6. The apparatus of claim 2 wherein the processing circuitry further includes a calibration circuit to adjust at least one detection characteristic of the PIN photodiodes.

7. The apparatus of claim 2 wherein the processing circuitry further includes a filter circuit.

8. The apparatus of claim 7 wherein the filter circuit includes one of a time-domain cross-talk filter and a weighted average noise compression filter.

9. The apparatus of claim 2 wherein the processing circuitry further includes a self-test circuit.

10. The apparatus of claim 2 wherein the PIN photodiodes share a common cathode.

11. The apparatus of claim 10 wherein the common cathode is disposed on a backside of the apparatus facing the electromagnetic radiation.

12. The apparatus of claim 11 wherein anode connections are made on a front side of the apparatus opposite the backside.

13. The apparatus of claim 12 further comprising a top cathode on the front side of the apparatus.

14. The apparatus of claim 13 wherein the top cathode includes cathode rings.