Specific Process Knowledge/Thermal Process/C4 Aluminium Anneal furnace: Difference between revisions
| Line 71: | Line 71: | ||
In November 2023 an oxygen (O<sub>2</sub>) mass flow controller was connected to the furnace, so that it became possible to oxidize different wafers and samples in the furnace. | In November 2023 an oxygen (O<sub>2</sub>) mass flow controller was connected to the furnace, so that it became possible to oxidize different wafers and samples in the furnace. | ||
The C4 furnace is made for processing of 4" wafers placed vertically in a quartz boat. However, it is possible to process 6" wafers (or small | The C4 furnace is made for processing of 4" wafers placed vertically in a quartz boat. However, it is possible to process 6" wafers (or small samples placed on a 6" wafer), if they are placed horizontally on the boat. | ||
Normally only one 6" wafer is | Normally only one 6" wafer is being processed, because the temperature flat zone, i.e. the area inside the furnace where the temperature is uniform, is only a little longer than one quartz boat. But because there are two quartz boats available for the furnace, it has also been tried to place a 6" wafer on each boat and oxidize them at the same time as explained here. | ||
<b>Sample loading:</b> | |||
One 6" wafer was placed on each of the two quartz boats. The wafer flats were pointing towards each other, and the boats were centered above the arrow on the cantilever. The loading procedure is explained in the user manual for the furnace, but users should not do this without training, as the wafers might collide with the furnace tube, when the door closes (the tube diameter is 160 mm, and the wafer diameter is 150 mm). In order improve the temperature uniformity over the two 6" wafers, two 4" dummy wafers were placed in the end of each boat. | |||
The 6" wafer closest to the furnace door/cleanroom is numbered "w1", and the wafer closest to the furnace/service room is numbered "w2". See the image below. | |||
<b>Process parameters:</b> | <b>Process parameters:</b> | ||
For the oxidation, the following process parameters were used: | |||
* Recipe: "DRY1050" | * Recipe: "DRY1050" | ||
* Oxidation temperature: 1050 <sup>o</sup>C | * Oxidation temperature: 1050 <sup>o</sup>C | ||
| Line 87: | Line 92: | ||
[[image:Oxidation test 1.jpg|600x600px|left|thumb|Two 6" | <b>Results:</b> | ||
After the oxidation, the thickness of the oxide layer grown on the 6" wafers was measured in five points on each wafer using the Ellipsometer VASE. | |||
The measurement results are shown below. | |||
<i>Pernille Voss Larsen, DTU Nanolab, November 2023</i> | |||
[[image:Oxidation test 1.jpg|600x600px|left|thumb|Two 6" wafers loaded in the C4 furnace. Two 4" dummy wafers are placed in the end of each boat.]] | |||
[[image:Oxidation test 2.jpg |700x700px|left|thumb|Oxide thickness measured on the two 6" wafers]] | [[image:Oxidation test 2.jpg |700x700px|left|thumb|Oxide thickness measured on the two 6" wafers]] | ||