Specific Process Knowledge/Thin Film deposition/ALD/TiO2 deposition using ALD: Difference between revisions
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image:ALD_TiO2_grow_rate_250C.jpg| Temperature 200 <sup>o</sup>C. | image:ALD_TiO2_grow_rate_250C.jpg| Temperature 200 <sup>o</sup>C. | ||
image:ALD_TiO2_grow_rate_350C.jpg| Temperature 250 <sup>o</sup>C. | image:ALD_TiO2_grow_rate_350C.jpg| Temperature 250 <sup>o</sup>C. | ||
</gallery> | |||
Below some SEM images of anatase TiO<sub>2</sub> deposited on trenches are shown. | |||
<gallery caption="Anatase TiO<sub>2</sub> deposited on a Si sample with trenches. Temperature = 120 <sup>o</sup>C, number of cycles = 500. Trench width = 200 nm, trench depth = 4 \mum, i.e. the aspect ratio is 1:20. It is seen that the TiO<sub>2</sub> covrets the trenches very well" widths="250px" heights="250px" perrow="5"> | |||
image:ALD Al2O3 grow rate 150C.jpg| Temperature 150 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 200C.jpg| Temperature 200 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 250C.jpg| Temperature 250 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 200C.jpg| Temperature 300 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 350C.jpg| Temperature 350 <sup>o</sup>C. | |||
</gallery> | |||
Below some SEM images of amorphous TiO<sub>2</sub> deposited on trenches are shown | |||
<gallery caption="Amorphous TiO<sub>2</sub> deposited a Si sample with trenches. Temperature = 350 <sup>o</sup>C, number of cycles = 500. Trench width = 200 nm, trench depth = 4 \mum, i.e. the aspect ratio is 1:20. It is seen that the TiO<sub>2</sub> covrets the trenches very well" widths="250px" heights="250px" perrow="5"> | |||
image:ALD Al2O3 grow rate 150C.jpg| Temperature 150 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 200C.jpg| Temperature 200 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 250C.jpg| Temperature 250 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 200C.jpg| Temperature 300 <sup>o</sup>C. | |||
image:ALD Al2O3 grow rate 350C.jpg| Temperature 350 <sup>o</sup>C. | |||
</gallery> | </gallery> | ||
Evgeniy Shkondin, DTU Danchip, 2014. | Evgeniy Shkondin, DTU Danchip, 2014. | ||
Revision as of 13:02, 8 May 2015
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The ALD window for titanium dioxide (TiO2) ranges from 120 oC to 350 oC.
A low temperatures between 120 oC and 150 oC an anatase TiO2 layer is grow in the ALD, and at higher temperatures between 300 oC and 350 oC and amorphous TiO2 layer is grown in the ALD. At temperatures between 150 oC and 300 oC the TiO2 layer will be a mixture of both anatase and amorphous TiO2.
SEM images of both anatase and amorphous TiO2 are shown below.
For Si wafers, anatase TiO2 is best grown wafers without native oxide (do an BHF etch), and amorphous TiO2 is best grown on wafers with native oxide.
XPS measurements shows that at temperaturs below 120 oC the TiO2 layer will be contaminated with about 1-3 % chlorine molecules from the TiCl4 precursor.
All results shown on this page have been obtained using the "TiO2" recipe on new Si(100) wafers with native oxide:
Recipe: TiO2
Temperature: 150 oC - 350 oC
| TMA | H2O | |
|---|---|---|
| Nitrogen flow | 150 sccm | 200 sccm |
| Pulse time | 0.1 s | 0.1 s |
| Purge time | 3.0 s | 4.0 s |
In the graphs below the TiO2 thickness as function of number of cycles for deposition temperatures between 150 oC and 350 oC can be seen. From the equations the number of cycles required for a certain thickess can be calculated.
- Titanium oxide thickness as function of number of cycles
-
Temperature 150 oC. -
Temperature 200 oC. -
Temperature 250 oC.
Below some SEM images of anatase TiO2 deposited on trenches are shown.
- Anatase TiO<sub
-
Temperature 150 oC. -
Temperature 200 oC. -
Temperature 250 oC. -
Temperature 300 oC.
-
Temperature 350 oC.
Below some SEM images of amorphous TiO2 deposited on trenches are shown
- Amorphous TiO<sub
-
Temperature 150 oC.
-
Temperature 200 oC.
-
Temperature 250 oC.
-
Temperature 300 oC.
-
Temperature 350 oC.
Evgeniy Shkondin, DTU Danchip, 2014.