US 12,379,327 B2
High precision VPD-DC scan
Robert Beikler, Wettenberg (DE); William Mande, Wettenberg (DE); and Walter Boehme, Wettenberg (DE)
Assigned to PVA TEPLA AG, Wettenberg (DE)
Filed by PVA TePla AG, Wettenberg (DE)
Filed on Sep. 9, 2022, as Appl. No. 17/941,032.
Claims priority of application No. 10 2021 126 728.5 (DE), filed on Oct. 14, 2021.
Prior Publication US 2023/0118379 A1, Apr. 20, 2023
Int. Cl. G01N 21/95 (2006.01); G01N 35/10 (2006.01); H01L 21/67 (2006.01)
CPC G01N 21/9501 (2013.01) [G01N 35/1011 (2013.01); H01L 21/67288 (2013.01); G01N 2021/9511 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of performing VPD-DC on wafer surfaces, comprising the steps of:
a) placing a wafer that is etched on a rotatable scan table;
b) positioning a pipette and the wafer relative to each other such that a tip of the pipette is in close proximity, but not in contact with a surface of the wafer;
c) operating the pipette such that a bulge of scanning liquid protrudes from a the pipette channel of the pipette and contacts the wafer surface of the wafer; and
d) rotating the wafer to guide the bulge of the scanning liquid protruding from the pipette channel along the wafer surface, wherein the method utilizes a bevel scanning VPD-DC for scanning,
wherein in step b), the pipette and the wafer are positioned relative to each other such that the tip of the pipette is close to a bevel of the wafer but not in contact with the bevel of the wafer, and wherein in step d) said rotating guides the bulge of the scanning liquid bulge protruding from the pipette channel along the bevel of the wafer, and wherein said method comprises centering the wafer on a horizontal scan table using a camera.