Apparatus method for testing opening state for hole in semiconductor device

• US 6,177,681 B1
• Filed: 01/25/1999
• Issued: 01/23/2001
• Est. Priority Date: 01/27/1998
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nakamura, Toyokazu
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/236,332
• Time in Patent Office: 729 Days
• Field of Search: 250/559.42, 250/559.43, 250/559.45, 250/341.4, 250/343, 250/306, 250/307, 356/237.6, 356/237.1, 356/73
• US Class Current: 250/559.42
• CPC Class Codes: G01N 21/9501 Semiconductor wafers manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10

Abstract

A testing apparatus for an opening state of a hole in a semiconductor device includes a laser light radiating system. The semiconductor device has the conductive layer and the insulating layer formed on the conductive layer, and the hole is formed in the insulating layer at aim to reach the conductive layer. The laser light radiating system radiates to a hole, a laser light having a wave length determined based on a work function of a material of a conductive layer and a work function of a material of an insulating layer. A detector detects photoelectrons emitted through a portion of the hole to which the laser light is irradiated. A charge supplementing mechanism supplies electrons to the conductive layer.

Claims

1. A testing apparatus for an opening state of a hole in a semiconductor device comprising:

a laser light radiating system for radiating, to a hole, a laser light having a wave length determined based on a work function of a material of a conductive layer and a work function of a material of an insulating layer, wherein said semiconductor device has said conductive layer and said insulating layer formed on said conductive layer, and said hole is formed in said insulating layer at aim to reach said conductive layer;

a detector for detecting that photoelectrons are emitted through a portion of said hole to which said laser light is irradiated; and

a charge supplementing mechanism for supplementing electrons to said conductive layer.

2. A testing apparatus according to claim 1, wherein said wave length of said laser light is a wave length corresponding to an energy in a range in which an outer photo-electric effect is performed to said conductive layer but the outer photo-electric effect is not performed to said insulating layer.

3. A testing apparatus according to claim 1, wherein said laser light is focused on and radiated to a bottom surface of said hole, and it is determined based on the detecting result by said detector whether or not said hole is opened to reach said conductive layer.

4. A testing apparatus according to claim 1, wherein said charge supplementing mechanism includes an electron beam source for sending said electrons to said conductive layer.

5. A testing apparatus according to claim 1, wherein said charge supplementing mechanism is connection of said conductive layer of said semiconductor device to the ground to send the electrons to said conductive layer.

6. A testing apparatus according to claim 4, further comprising a controller for controlling said laser light radiating system and said electron beam source such that said radiation of said laser light and said electron supplement to said conductive layer by said electron beam source are alternately carried out.

7. A testing apparatus according to claim 1, wherein said semiconductor device has a plurality of said holes and a focused beam diameter of said laser light is larger than a diameter of said hole.

8. A testing apparatus according to claim 1, wherein said laser light radiating system has an optically scanning system for scanning said laser light in a two-dimension direction such that said laser light is sequentially radiated to said plurality of holes.

9. A testing apparatus according to claim 1, wherein said laser light radiating system includes:

an optically scanning system for scanning said laser light in a one-dimension direction such that said laser light is sequentially radiated to a row of said plurality of holes; and

a driver for scanning said semiconductor device in a direction orthogonal to a scanning direction of said laser light, in response to the scan of said laser light.

10. A testing apparatus according to claim 1, further comprising a driver for scanning said semiconductor device in a two-dimension direction such that said laser light is sequentially radiated to said plurality of holes.

11. A testing apparatus according to claim 1, wherein said detector is a light electron detector.

12. A testing apparatus according to claim 1, wherein said detector is an ammeter connected between said conductive layer and the ground.

13. A testing apparatus according to claim 1, further comprising:

a display; and

a display controller for controlling said display such that the detecting result by said detector is displayed on said display with respect to a relative position of said semiconductor device and said laser light.

14. A testing apparatus according to claim 13, wherein said display controller controls said display such that the detecting result by said detector for each of said plurality of holes in said semiconductor device is displayed on said display as a two-dimension contrast image having a brightness distribution proportional to said detection result.

15. A testing apparatus according to claim 4, further comprising alternately performing said radiation of said laser light and said supplement of said electrons to said conductive layer.

16. A method of testing an opening state of a hole in a semiconductor device, comprising the steps of:

radiating to one of a plurality of holes, a laser light pulse having a wave length determined based on a work function of a material of a conductive layer and a work function of a material of an insulating layer, wherein said semiconductor device has said conductive layer and said insulating layer formed on said conductive layer and said plurality of holes are formed in said insulating layer at aim to reach said conductive layer;

detecting that photoelectrons are emitted through said hole in response to said laser light; and

supplementing electrons to said conductive layer after said laser light pulse is radiated.

17. A method according to claim 16, wherein said radiating step includes radiating said laser light pulse such that said laser light is focused on and radiated to a bottom surface of said hole, and

wherein said detecting step includes determining whether or not said hole is opened to reach said conductive layer, based on the detecting result.

18. A method according to claim 16, wherein said supplementing step includes irradiating electrons to said conductive layer.

19. A method according to claim 16, wherein said supplementing step includes connecting said conductive layer of said semiconductor device to the ground.

20. A method according to claim 16, wherein said wave length of said laser light is a wave length corresponding to an energy in a range in which an outer photo-electric effect is performed to said conductive layer but the outer photo-electric effect is not performed to said insulating layer.

21. A method according to claim 16, wherein said semiconductor device has a plurality of said holes and a focused beam diameter of said laser light is larger than a diameter of said hole.

22. A method according to claim 16, further comprising the step of relatively scanning said semiconductor device and said laser light pulse.

23. A method according to claim 22, wherein said relatively scanning step includes optically scanning said laser light in a two-dimension direction.

24. A method according to claim 22, wherein said relatively scanning step includes:

scanning said laser light in a one-dimension direction; and

scanning said semiconductor device in a direction orthogonal to a scanning direction of said laser light.

25. A method according to claim 22, wherein said relatively scanning step includes scanning said semiconductor device in a two-dimension direction.

26. A method according to claim 16, further comprising the step of:

displaying the detecting result of said photoelectrons as a two-dimension contrast image having a brightness distribution proportional to said detection result.