Practical Electron Microscopy and Database

An Online Book, Second Edition by Dr. Yougui Liao (2006)

Practical Electron Microscopy and Database - An Online Book

Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix

IC Failure Induced during Wafer Packaging and Shipping

Table 2430. Bond-pad contamination in IC devices induced during wafer packaging and shipping.

Contaminant
Contamination sources
Effects
Fluorine

Introduced through top metal etch or pad opening process, wafer packaging foam material, or shipping

 

Induce non-sticking bond pad

 

Fluorine can
react with Al to form F crystal: (NH4)3(AlF6) compound [1]; High fluorine contamination can induce thick native oxide
Oxygen
Introduced during backside grinding process or pad opening process (e.g. formed AlxFyOz), by reactive epoxy diluents, or by package paper during shipping (e.g. containing Al, F, O, and K) [e.g. Figure 2430]
Kalium
Introduced by package paper during shipping

Figure 2430 shows an example of C, O, and Si contaminated bond pads. Area S6 had an abnormal film on the native Al oxide, while area S5 presented nonhomogeneous, loose and empty SixAlyCzOm materials in the hemispherical defect.  These pad defects existed only at wafer edge because backside grinding was the root cause of the contamination.

Contaminated bond pads

Figure 2430. Contaminated bond pads. Adapted from [2]

 

 

 

 

[1] Y. N. Hua, S. Redkar, C. K. Lau, “A Study on Non- Stick Aluminium Bondpads due to Fluorine Contamination using SEM, EDX, TEM, IC, Auger, XPS and TOF-SIMS Techniques,” Proceedings from the 28th International Symposium for Testing and Failure Analysis, Phoenix, Arizona, November, 2002, pp. 495-504.
[2] Paul Yu, Jamie Su, Qiang Gao, Ming Li, Chorng Niou, Study of Aluminum Pad Contamination Sources during Wafer Fabrication, Shipping, Storage and Assembly, International Symposium on High Density packaging and Microsystem Integration, 2007. HDP '07.

 

 

 

Contact the Book Author | About the Book Author | Join EM Group Chats

Citation of the Online Book Listed on Google Scholar