Method for depositing an epitaxial layer on a substrate wafer made of semiconductor material in a deposition device

1 . A method for depositing an epitaxial layer on a substrate wafer of semiconductor material in a deposition apparatus, the method comprising:

placing the substrate wafer on a susceptor of the deposition apparatus, the susceptor being surrounded, separated by a gap, from a preheat ring, and the susceptor being held by a supporting shaft having a supporting shaft axis, which is the axis of rotation of the supporting shaft;

determining an offset between a preheat ring axis and a susceptor axis, the preheat ring axis being perpendicularly through the center of the preheat ring, and the susceptor axis being perpendicularly through the center of the susceptor;

determining a displacement path by: determining a starting position as being where the supporting shaft axis is arranged along the preheat ring axis; and determining an end position based on the starting position and the offset;

passing deposition gas over the substrate wafer along a flow direction pointing from a gas inlet to a gas outlet;

passing purge gas along a lower side of the preheat ring and a lower side of the susceptor;

rotating, with a rotation frequency, the supporting shaft about the supporting shaft axis; and

during each rotation of the supporting shaft, displacing the supporting shaft from the starting position to the end position and back to the starting position at a frequency matching the rotation frequency.

2 . The method as claimed in claim 1 , wherein the displacement path from the starting position to the end position is described by a vector whose magnitude is the magnitude of the offset and whose direction is opposite to the direction of the offset.

3 . The method as claimed in claim 2 , wherein the displacement path from the starting position to the end position is described by a resultant vector of a vector sum with the vector and a further vector as summands, the magnitude of the further vector being proportional to a ratio of a greatest and smallest cross-sectional thickness of the substrate wafer and the direction of the further vector being the same as the flow direction of the deposition gas.

4 . The method as claimed in claim 1 , wherein the supporting shaft is displaced by at least one actuator.

5 . The method as claimed in claim 1 ,

wherein the offset is determined as an offset vector defining an offset magnitude and an offset direction,

wherein the method further comprises determining a displacement vector based on the offset vector such that the displacement vector has a displacement magnitude that is the magnitude of the offset magnitude and has a displacement direction that is opposite to the offset direction, and

wherein the determining of the end position based on the starting position and the offset comprises determining the end position as a shift from the starting position according to the displacement vector.

6 . The method as claimed in claim 1 ,

wherein the offset is determined as an offset vector defining an offset magnitude and an offset direction,

wherein the method further comprises:

determining a displacement vector based on the offset vector such that the displacement vector has a displacement magnitude that is the magnitude of the offset magnitude and has a displacement direction that is opposite to the offset direction;

determining a wedge characteristic of the substrate wafer as a ratio between a greatest and smallest cross-sectional thickness of the substrate wafer; and

determining a further vector as having a direction as the flow direction and having a magnitude determined based on the wedge characteristic of the substrate wafer, and

wherein the determining of the end position based on the starting position and the offset comprises determining the end position as a shift from the starting position according to a sum of the displacement vector and the further vector.