Method of testing, wafer, and testing station

Patent metadata

Field	Value
Publication number	US-2024012043-A1
Application number	US-202118245997-A
Country	US
Kind code	A1
Filing date	Sep 23, 2021
Priority date	Sep 23, 2020
Publication date	Jan 11, 2024
Grant date	—

Abstract

A method of testing one or more optoelectronic devices located on respective device coupons. The device coupon(s) are present on a wafer. The method comprises: testing the or each optoelectronic device using a corresponding testing element, the testing element(s) being located on the same wafer as the device coupon(s), by either: in a first testing protocol, operating the optoelectronic device so as to produce an optical output, and detecting the light incident on the testing element from the optoelectronic device under test, or in a second testing protocol, detecting, by the optoelectronic device under test, the light received from the testing element.

First claim

1 . A method of testing one or more optoelectronic devices located on respective device coupons, the device coupon(s) being present on a wafer, the method comprising:
testing the or each optoelectronic device using a corresponding testing element, the testing element(s) being located on the same wafer as the device coupon(s), by either: in a first testing protocol, operating the optoelectronic device so as to produce an optical output, and detecting the light incident on the testing element from the optoelectronic device under test, or in a second testing protocol, detecting, by the optoelectronic device under test, light received from the testing element.

2 . The method of claim 1 , wherein there is a plurality of optoelectronic devices located on respective device coupons, and wherein under the first testing protocol the testing element is one of the optoelectronic devices which is:
adjacent the optoelectronic device of the plurality of optoelectronic devices which is under test, and placed under a reverse bias so as to operate as a photodiode

3 . The method of claim 2 , wherein the testing element is a photodiode.

4 . The method of claim 3 , including a plurality of optoelectronic devices located on respective device coupons, wherein the photodiode is incorporated in a device coupon adjacent to the optoelectronic device under test.

5 . The method of claim 4 , wherein the photodiode is formed in the wafer.

6 . The method of claim 4 or 5 , wherein the photodiode includes a rough facet or an anti-reflective coating.

7 . The method of any of claims 4 - 6 , wherein the photodiode includes an angled facet, configured to direct light towards the wafer.

8 . The method of claim 1 , wherein the testing element is a reflector, which couples the optoelectronic device under test to an optical fibre located above the wafer.

9 . The method of claim 8 , wherein, in the first testing protocol, light from the optoelectronic device under test is reflected into the optical fibre and detected.

10 . The method of claim 8 , wherein, in the second testing protocol light is provided from the optical fibre and reflected via the testing element to the optoelectronic device under test.

11 . The method of claim 1 , wherein under the second testing protocol, the testing element is a laser on an adjacent device coupon, which is operated to illuminate the optoelectronic device under test.

12 . A wafer, including one or more optoelectronic devices located on respective device coupons, the wafer further comprising a corresponding testing element for the or each optoelectronic device.

13 . The wafer of claim 12 , comprising a plurality of optoelectronic devices located on respective device coupons, wherein the testing element is an optoelectronic device on a device coupon adjacent to the optoelectronic device under test, operable in reverse bias as a photodiode.

14 . The wafer of claim 12 , wherein the testing element is a photodiode.

15 . The wafer of claim 14 , comprising a plurality of optoelectronic devices located on respective device coupons, wherein the photodiode is incorporated in a device coupon adjacent to the optoelectronic device under test.

16 . The wafer of claim 14 , wherein the photodiode is formed in the wafer.

17 . The wafer of claim 15 or 16 , wherein the photodiode includes a rough facet or an anti-reflective coating.

18 . The wafer of any of claims 15 — 17 , wherein the photodiode includes an angled facet, configured to direct light towards the wafer.

19 . The wafer of claim 12 , wherein the testing element is a reflector, which is configured to couple the optoelectronic device under test to an optical fibre.

20 . A testing station for testing one or more optoelectronic devices mounted to respective device coupons, the testing station comprising:
a receptacle for receiving a wafer according to any of claims 12 - 19 ; and electrodes, connectable to the or each optoelectronic device and/or the or each testing element, and configured in a first testing protocol, to provide a photocurrent to an optoelectronic device under test, and monitor a photocurrent generated from light incident on the corresponding testing element; and/or in a second testing protocol, to provide light via the testing element to an optoelectronic device under test, and monitor the photocurrent generated by the optoelectronic device under test.

Assignees

• Rockley Photonics Ltd

Inventors

• Dernaika Mohamad
• Caro Ludovic
• Perrott Alison
• Yang Hua
• Peters Frank

Classifications

• G01R31/2635 Primary

  Testing light-emitting diodes, laser diodes or photodiodes · CPC title

• H02S50/10 Primary

  Testing of PV devices, e.g. of PV modules or single PV cells (testing of semiconductor devices during manufacturing {H10P74/00}) · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• G01R31/308

  using non-ionising electromagnetic radiation, e.g. optical radiation {(investigating or analysing materials by the use of optical means G01N21/00; image analysis G06T7/00)} · CPC title