The Effect of Chemical Cleaning on Bulk Traps in Dry Gate Oxide

Hidetsugu UCHIDA  Norio HIRASHITA  Tsuneo AJIOKA  

IEICE TRANSACTIONS on Electronics   Vol.E75-C   No.7   pp.790-795
Publication Date: 1992/07/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Ultra Clean Technology)
hole trap,  electron trap,  chemical cleaning,  SiO2,  avalanche injection,  

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The hole-trapping and electron-trapping characteristics in dry oxides following various chemical cleanings have been studied using the avalanche injection method. The results indicated that hole trap density was almost the same for the chemical cleanings. Electron traps with two capture cross sections, σ, were observed. Electron traps with σ210-17 cm2 were found to be independent of the chemical cleaning, while those with σ410-19 cm2 to depend on the cleaning. Comparison with previous works indicated that electron traps with larger σ were related to Si-OH bonds. The other electron trap showed the increasing trapping rate with increasing the current density injected into oxide. This was explained by trap generation due to electron injection. A correlation between the density of generated electron traps and the amount of Al contamination on surfaces before dry oxidation was observed.