Tris-diethylamino-silane decomposition due to tetrakis-diethylamido-hafnium in Hf1-xSixO2 chemical vapor deposition

Tris-diethylamino-silane SiH(NEt2)(3) is stable and does not decompose by itself below 550degreesC. However, it easily decomposes even at 150degreesC with the addition of tetrakis-diethylamido-hafnium (Hf(NEt2)(4)). This enhancement of silicon source decomposition, determined the properties of Hf1-xSixO2 film, when the Hf1-xSixO2 film is deposited by CVD using the Hf(NEt2)(4)/SiH(NEt2)(3)/O-2 gas system. Then 550degreesC, the Si concentration is almost constant and the ratio of N to Si is almost one independent of the deposition temperature. However, above 550degreesC, the Si concentration increases and the ratio of N to Si decreases, since SiH(NEt2)(3) is thermally decomposed by itself.