Optical antennas for advanced integrated circuit testing

Patent metadata

Field	Value
Publication number	US-2016313395-A1
Application number	US-201615203282-A
Country	US
Kind code	A1
Filing date	Jul 6, 2016
Priority date	Jan 6, 2014
Publication date	Oct 27, 2016
Grant date	—

Abstract

A device testing approach employs optical antennas at test locations of a semiconductor device, usable as either/both radiators or receivers. As a radiator, an antenna responds to localized optical energy at a test location of the device to generate corresponding radiated optical energy that can be sensed and processed by a test system. As a receiver, an antenna receives radiated optical energy as generated by a test system and converts the energy into corresponding localized optical energy for affecting operation of the device. The optical antennas may be formed from metal segments on the same metal layers used for signal interconnections in the device, and thus the disclosed approach can provide enhanced test functionality without burdening the device manufacturing process with additional complexity solely to support testing. The testing approach may be used in different modalities in which the antennas variably act as transmitters, receivers, and reflectors/refractors.

First claim

What is claimed is:

1 . A semiconductor device, comprising:
functional circuit elements formed by registered and interconnected segments of semiconductor material and metal at respective layers of the device; and optical antennas formed as optical test points at selected test locations for the functional circuit elements on the device, the optical antennas converting between radiated optical energy to or from a test system and corresponding localized optical energy at the test locations.

2 . A semiconductor device according to claim 1 , wherein the optical antennas are constituted by segments of metal formed at one or more metal interconnection layers of the semiconductor device.

3 . A semiconductor device according to claim 2 , wherein the metal interconnection layers include a first layer metal closest to an active semiconductor layer of the semiconductor device.

4 . A semiconductor device according to claim 2 , wherein one or more of the optical antennas is a vertical antenna formed by segments of metal from multiple adjacent metal layers.

5 . A semiconductor device according to claim 1 , wherein circuitry at the test locations operates in response to the localized optical energy to create a light-induced change of a local electrical parameter selected from a voltage and a current.

6 . A semiconductor device according to claim 1 , wherein circuitry at the test locations operates in response to a light-induced local temperature change caused by the localized optical energy.

7 . A semiconductor device according to claim 1 , wherein the functional circuit elements include two devices located sufficiently close to each other that their locations cannot be resolved based on the radiated optical energy, and wherein an optical antenna is located and configured such that the respective localized optical energy is localized at one of the devices to permit resolution of the devices by the test system.

8 . A semiconductor device, comprising:
functional circuit elements formed by a pattern of registered and interconnected segments of semiconductor material and metal at respective layers of the device; and optical antennas formed by a pattern of segments of antenna material included in the layers of the device, the optical antennas being dimensioned and configured to respond to incident radiated optical energy by generating a predetermined pattern of radiated optical energy uniquely associated with the pattern of segments of antenna material.

9 . A method of manufacturing and testing of a semiconductor device, comprising:
incorporating optical antennas at test locations of the semiconductor device, the antennas being configured and operable to transmit radiated optical energy away from the semiconductor device in response to localized optical energy at the test locations; operating the semiconductor device to cause functional circuit elements at the test locations to emit the localized optical energy having a pattern indicative of specific operations of the functional circuit elements; sensing the radiated optical energy and converting it into one or more corresponding electrical signals representative of the localized optical energy at the test locations of the semiconductor device; and processing the electrical signals by a test controller to determine whether the electrical signals indicate that the functional circuit elements operate in accordance with a predetermined test criteria.

10 . A method according to claim 9 , wherein the sensing is performed using a backside optical imaging mode collecting the optical energy as radiated from a back surface of the semiconductor device.

11 . A method according to claim 9 , wherein the sensing is performed using a front-side optical imaging mode collecting the optical energy as radiated from a front surface of the semiconductor device.

12 . A method according to claim 9 , wherein the optical energy is in the near infrared range.

13 . A method of manufacturing and testing of a semiconductor device, comprising:
incorporating optical antennas at test locations of the semiconductor device, the antennas being configured and operable to convert radiated optical energy directed at the semiconductor device to localized optical energy at the test locations; operating a test controller to generate electrical signals indicative of optical energy to be directed to the test locations, and converting the electrical signals into corresponding optical signals and radiatively transmitting the optical signals to the optical antennas to deliver the localized optical energy to the corresponding test locations, the localized optical energy causing functional circuit elements at the test locations to perform specific operations; sensing and processing electrical signals from the functional circuit elements indicative of operation of the functional circuit elements in response to the localized optical energy, the processing performed by the test controller and determining whether the electrical signals indicate that the functional circuit elements operate in accordance with a predetermined test criteria.

14 . A method of verifying correct manufacture of a semiconductor device, comprising:
generating a pattern of radiated optical energy and direct it to the semiconductor device, the semiconductor device when correctly manufactured including (i) functional circuit elements formed by a pattern of registered and interconnected segments of semiconductor material and metal at respective layers of the device, and (ii) optical antennas formed by a pattern of segments of antenna material included in the layers of the device, the optical antennas being dimensioned and configured to respond to the radiated optical energy by generating a corresponding predetermined pattern of radiated optical energy uniquely associated with the pattern of segments of antenna material; and sensing an actual pattern of optical energy radiating from the device and comparing it to the predetermined pattern, the comparing generating a match indication when the compared patterns match to at least a predetermined minimum degree, and otherwise refraining from generating the match indication.

15 . A method according to claim 14 , wherein the match indication reflects proper overlay registration of separate layers of the semiconductor device.

16 . A method according to claim 14 , wherein the match indication confirms that a design and/or layout of the device does not deviate from an expected design and/or layout.

17 . A method according to claim 14 , wherein the predetermined pattern of radiated optical energy is generated by the optical antennas when the semiconductor device is in a non-operating state in which no additional light is being generated by functional circuit elements at the test locations; and
the method is performed with the semiconductor device in the non-operating state.

18 . A method according to claim 14 , wherein the predetermined pattern of radiated optical energy is generated by the optical antennas when the semiconductor device is in an operating state in which localized light is being generated by functional circuit elements at the test locations, the predetermined pattern of radiated optical energy including a first light component from the pattern of radiated optical energy directed to the semiconductor device and a second light component generated by the optical antennas in response to the localized light; and
the method is performed with the semiconductor device in the operating state.

19 . A m

Assignees

• Univ Boston

Inventors

• Ünlü M Selim
• Goldberg Bennett B
• Leblebici Yusuf

Classifications

• H10P74/207

  Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics · CPC title

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H01L22/12

  Electricity · mapped topic

• G01R31/2856

  Internal circuit aspects, e.g. built-in test features; Test chips; Measuring material aspects, e.g. electro migration [EM] · CPC title

• G01R31/311 Primary

  of integrated circuits {(G01R31/31728 takes precedence)} · CPC title