Effects of Sample Cooling on Depth Profiling of Na in SiO2 Thin Films

✍ Scribed by Vajo, John J.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 237 KB
• Volume: 25
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199704)25:4<295::aid-sia237>3.0.co;2-u

✦ Synopsis

Depth proÐling using secondary ion mass spectrometry of a 100 keV Na implant in a 430 nm thick Ðlm has SiO 2 been studied as a function of temperature from 295 to 93 K. At 295 K, and using a coincident electron Ñux to reduce the extent of electric Ðeld-induced Na migration, accumulation of Na at the interface could be eliminated. However, proÐles at 295 K without Na accumulation were difficult to reproduce. In addition, the trailing edges often did not decrease exponentially and are broadened with decay lengths > 44 nm. At 93 K and using the electron Ñux only to maximize the matrix secondary ion signals, accumulation of Na at the interface was eliminated, the trailing edge decreased exponentially and the decay length was reduced to 27 nm. Sample cooling also improved reproducibility and allowed a wider range of sputtering conditions to be used.