Imaging thin film structures by scanning acoustic microscopy

• US 20080022774A1
• Filed: 07/28/2006
• Published: 01/31/2008
• Est. Priority Date: 07/28/2006
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lu, Minhua
• Application Number:
  US11/495,243
• Publication Number:
  US 20080022774A1
• Time in Patent Office: Days
• US Class Current: 73/606
• CPC Class Codes: G01N 2291/0231 Composite or layered materials
• CPC Class Codes: G01N 2291/044 Internal reflections (echoes), e.g. on walls or defects
• CPC Class Codes: G01N 29/0681 by acoustic microscopy, e.g. scanning acoustic microscopy
• CPC Class Codes: G01N 29/225 Supports, positioning or alignment in moving situation
• CPC Class Codes: G01N 29/28 providing acoustic coupling , e.g. water impedance matching G10K11/02

Abstract

A method and apparatus for Scanning Acoustic Microscopy (SAM) for testing of a semiconductor device having a first surface and a second surface with bonding features secured to said first surface are provided. An impervious fixture comprising a dam or a tank retains acoustic transmission fluid in contact with the second surface. Acoustic transmission fluid is excluded from admission to the space surrounding the bonding features where an atmosphere of gas or a vacuum is provided by isolating the first surface from the acoustic transmission fluid either by providing a sealed chamber protecting the first surface or by providing a dam surrounding the second surface.

Claims

1. Apparatus for Scanning Acoustic Microscopy (SAM) of a semiconductor device with an acoustic probe, said semiconductor device including a substrate having a first surface and a second surface with bonding features secured to said first surface and with acoustic transmission fluid retained in contact with said second surface;

said apparatus comprising;

an environment surrounding said first surface, said environment comprising an atmosphere selected from a gas and a vacuum;

a barrier in contact with one of said first surface and said second surface sealed to prevent said acoustic transmission fluid from being admitted to said environment surrounding said first surface; and

an acoustic scanning probe positioned confronting said second surface of said semiconductor device extending into said acoustic transmission fluid retained in contact with said second surface.

2. The apparatus of claim 1 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads and solder bonding elements.

3. The apparatus of claim 1 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads, solder bonding elements and a substrate.

4. The apparatus of claim 1 including a sealed chamber secured to said first surface of said semiconductor device with said sealed chamber isolating said bonding features from said acoustic transmission fluid.

5. The apparatus of claim 4 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads and solder bonding elements.

6. The apparatus of claim 4 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads, solder bonding elements and a substrate.

7. The apparatus of claim 1 wherein:

said acoustic transmission fluid comprises water, and

a sealed chamber is secured to said first surface of said semiconductor device with said sealed chamber comprising a gas filled chamber separating said bonding features from said water.

8. The apparatus of claim 7 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads, solder bonding elements and a substrate.

9. The apparatus of claim 1 wherein

said acoustic transmission fluid comprises water, and

a sealed vacuum chamber is secured to said first surface of said semiconductor device with said sealed vacuum chamber separating said bonding features from said water.

10. The apparatus of claim 9 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads and solder bonding elements.

11. The apparatus of claim 1 including an impervious, physical barrier secured to one of said first surface and said second surface of said semiconductor device separating said bonding features from said acoustic transmission fluid.

12. The apparatus of claim 11 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads, solder bonding elements and a substrate.

13. Apparatus for Scanning Acoustic Microscopy (SAM) of a semiconductor device having a first surface and a second surface with bonding features secured to said first surface comprising:

a tank for retaining acoustic transmission fluid;

an impervious fixture retained in sealed contact with said first surface defining an interior space surrounding said bonding features, said impervious fixture being filled with an atmosphere selected from the group consisting of a vacuum, air and gas and being sealed to exclude said acoustic transmission fluid from admission to said interior space.

14. A method of testing a semiconductor device employing Scanning Acoustic Microscopy (SAM) of a semiconductor device having a first surface and a second surface with bonding features secured to said first surface comprising:

retaining acoustic transmission fluid in contact with said second surface;

providing a atmosphere surrounding said first surface, said atmosphere being selected from the group consisting air, gas, and a vacuum and separating said acoustic transmission fluid from said atmosphere surrounding said first surface; and

positioning a SAM acoustic scanning probe confronting said second surface of said semiconductor device extending into said acoustic transmission fluid.

15. The method of claim 14 including providing a sealed chamber secured to said first surface of said semiconductor device separating said bonding features from said acoustic transmission fluid.

16. The method of claim 14 wherein:

said acoustic transmission fluid comprises water, and

providing a sealed chamber secured to said first surface of said semiconductor device with said sealed chamber separating said bonding features from said water.

17. The method of claim 14 wherein:

said acoustic transmission fluid comprises water, and

providing a sealed vacuum chamber secured to said first surface of said semiconductor device with said sealed vacuum chamber separating said bonding features from said water.

18. The method of claim 14 including:

providing a tank for retaining acoustic transmission fluid;

providing an impervious fixture retained in sealed contact with said first surface defining an interior space and surrounding said bonding features filled with an atmosphere selected the group consisting of a vacuum, air and gas, and

excluding said acoustic transmission fluid from admission to said interior space.

19. The method of claim 14 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads and solder bonding elements.

20. The method of claim 14 wherein said bonding features comprise Ball-Limiting Metallurgy (BLM) pads, solder bonding elements and a substrate.