Multi-step location specific process for substrate edge profile correction for GCIB system
View Patent ↗Disclosed are an apparatus, system, and method for scanning a substrate or other workpiece through a gas-cluster ion beam (GCIB), or any other type of ion beam. The workpiece scanning apparatus is configured to receive and hold a substrate for irradiation by the GCIB and to scan it through the GCIB in two directions using two movements: a reciprocating fast-scan movement, and a slow-scan movement. The slow-scan movement is actuated using a servo motor and a belt drive system, the belt drive system being configured to reduce the failure rate of the workpiece scanning apparatus.
1. A method for treating a workpiece with a gas cluster ion beam (GCIB), comprising:
providing a workpiece, the workpiece being characterized by a surface attribute that exhibits a spatial variation between a peripheral edge region and an interior region;
performing a first scanning motion of the workpiece through a first GCIB along a rotational path that exposes the peripheral edge region of the workpiece to the first GCIB and reduces the spatial variation of the surface attribute between the peripheral edge region and the interior region; and
performing a second scanning motion of the workpiece through a second GCIB along a non-circular path that exposes the peripheral edge region and the interior region of the workpiece to the second GCIB.
2. The method of claim 1 , wherein the surface attribute comprises a film thickness, a surface profile, a surface roughness, a surface composition, a layer composition, a mechanical property of the workpiece, an electrical property of the workpiece, or an optical property of the workpiece, or any combination of two or more thereof.
3. The method of claim 1 , wherein the first GCIB differs from the second GCIB in at least one GCIB parameter.
4. The method of claim 1 , wherein the performing the first scanning motion comprises scanning the workpiece along a substantially circular path that begins and ends at the same or similar location.
5. The method of claim 1 , wherein the performing the first scanning motion comprises scanning the workpiece along two or more concentric circular paths.
6. The method of claim 1 , wherein the performing the first scanning motion comprises repetitively scanning the workpiece along a substantially circular path.
7. The method of claim 1 , wherein the performing the second scanning motion comprises repetitively scanning the workpiece along a linear or arcuate path across the workpiece.
8. The method of claim 1 , wherein the performing the first scanning motion comprises:
mounting the workpiece at a first end of an elongated member;
rotating the elongated member using a rotational mechanism attached to a point of rotation on the elongated member, the point of rotation being away from the first end, to make one or more scans of the workpiece through the first GCIB;
moving the elongated member and rotational mechanism along a slow-scan mechanism concurrently with the rotating, to which the rotational mechanism is attached and by which is suspended, the moving causing different portions of the peripheral edge region of the workpiece to pass through the first GCIB, along a rotational path.
9. The method of claim 1 , wherein the performing the second scanning motion comprises:
mounting the workpiece at a first end of an elongated member;
partially, repetitively rotating the elongated member using a rotational mechanism attached to a point of rotation on the elongated member, the point of rotation being away from the first end, to make one or more scans of the workpiece through the second GCIB, along an arcuate path;
moving the elongated member and rotational mechanism along a slow-scan mechanism, to which the rotational mechanism is attached and by which is suspended, the moving causing different portions of the workpiece to pass through the second GCIB path during the repetitive scans.
10. The method of claim 1 , further comprising varying a first GCIB dose during the performing the first scanning motion.
11. The method of claim 1 , further comprising varying a second GCIB dose during the performing the second scanning motion.