Lateral plasma/radical source
Plasma source assemblies comprising a housing with an RF hot electrode and a return electrode are described. The housing includes a gas inlet and a front face defining a flow path. The RF hot electrode includes a first surface oriented substantially parallel to the flow path. The return electrode includes a first surface oriented substantially parallel to the flow path and spaced from the first surface of the RF hot electrode to form a gap. Processing chambers incorporating the plasma source assemblies and methods of using the plasma source assemblies are also described.
1. A plasma source assembly comprising:
a wedge-shaped housing having a gas inlet and a front face defining a flow path, the gas inlet allowing a flow of gas to move along the flow path to pass through the housing and out the front face;
an RF hot electrode within the housing, the RF hot electrode having a first surface oriented substantially parallel to the flow path and a serpentine shape; and
a return electrode within the housing, the return electrode having a first surface oriented substantially parallel to the flow path and spaced from the first surface of the RF hot electrode to form a gap, the return electrode having a complementary shape to the RF hot electrode to maintain substantially the same gap along a length of the serpentine shape.
2. The plasma source assembly of claim 1 , further comprising a second return electrode, the second return electrode having a first surface oriented substantially parallel to the flow path and spaced from a second surface of the RF hot electrode to form a second gap, the second surface of the RF hot electrode opposite the first surface of the RF hot electrode.
3. The plasma source assembly of claim 1 , wherein the return electrode is a ground electrode.
4. The plasma source assembly of claim 1 , wherein the return electrode is a powered electrode different from the RF hot electrode.
5. The plasma source assembly of claim 1 , wherein the gap between the RF hot electrode and the return electrode is in the range of about 4 mm to about 15 mm.
6. The plasma source assembly of claim 1 , wherein the gap between the RF hot electrode and the return electrode changes from a narrower gap adjacent the gas inlet to a wider gap adjacent the front face.
7. The plasma source assembly of claim 6 , wherein the thickness of the RF hot electrode is greater adjacent the gas inlet than adjacent the front face.
8. The plasma source assembly of claim 1 , wherein the RF hot electrode has a thickness in the range of about 3 mm to about 11 mm.
9. The plasma source assembly of claim 1 , wherein the RF hot electrode has a height in the range of about 8 mm to about 40 mm.
10. The plasma source assembly of claim 1 , wherein the RF hot electrode and return electrode extend along a major axis of the housing.
11. The plasma source assembly of claim 1 , wherein the RF hot electrode and return electrode extend perpendicular to a major axis of the housing.
12. The plasma source assembly of claim 1 , wherein the RF hot electrode has a plurality of fingers extending perpendicular to a major axis of the housing.
13. The plasma source assembly of claim 12 , wherein the return electrode has a complementary shape to the RF hot electrode to maintain substantially the same gap between the RF hot electrode and the return electrode.
14. The plasma source assembly of claim 1 , further comprising a spacer adjacent a lower edge of the RF hot electrode.