Specific Process Knowledge/Thin Film deposition/ALD/TiO2 deposition using ALD: Difference between revisions
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The ALD window for titanium dioxide (TiO<sub>2</sub>) ranges from 120 <sup>o</sup>C to 350 <sup>o</sup>C. | The ALD window for titanium dioxide (TiO<sub>2</sub>) ranges from 120 <sup>o</sup>C to 350 <sup>o</sup>C. | ||
A low temperatures between 120 <sup>o</sup>C and 150 <sup>o</sup>C an | A low temperatures between 120 <sup>o</sup>C and 150 <sup>o</sup>C an amorphous TiO<sub>2</sub> layer is grown in the ALD, and at higher temperatures between 300 <sup>o</sup>C and 350 <sup>o</sup>C an anatase TiO<sub>2</sub> layer is grown. At temperatures between 150 <sup>o</sup>C and 300 <sup>o</sup>C the TiO<sub>2</sub> layer will be a mixture of both amorphous and anatase TiO<sub>2</sub>. | ||
For Si wafers, anatase TiO<sub>2</sub> is best grown on wafers without native oxide (removed using BHF), and amorphous TiO<sub>2</sub> is best grown on wafers with native oxide. | For Si wafers, anatase TiO<sub>2</sub> is best grown on wafers without native oxide (removed using BHF), and amorphous TiO<sub>2</sub> is best grown on wafers with native oxide. | ||
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image:TiO2 trenches-300C-3.jpg| | image:TiO2 trenches-300C-3.jpg| | ||
</gallery> | </gallery> | ||
XPS measurements of TiO<sub>2</sub> deposited at 120 <sup>o</sup>C and 300 <sup>o</sup>C are shown below. From the XPS measurements it can be calculated that at temperaturs below 120 <sup>o</sup>C the TiO<sub>2</sub> layer will be contaminated with about 1-3 % chlorine molecules from the TiCl<sub>4</sub> precursor. This can be also seen as small white dots in SEM images of the anatase TiO<sub>2</sub> layers above. | |||
[[image:XPS_TiO2.jpg|320x320px|left|thumb|XPS measurements of titanium dioxide]] | |||
Evgeniy Shkondin, DTU Danchip, 2014. | Evgeniy Shkondin, DTU Danchip, 2014. | ||