In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 36, No. 12S ( 1997-12-01), p. 7575-
Abstract:
We investigate the deposition of ultra low and uniform stress absorbers for highly accurate X-ray masks. We calculate the maximum overlay error between two masks having different absorber coverages as parameters of absorber stress peak-to-valley (pv) value and distribution shape in order to establish the criteria of absorber stress, which suggested that less than 10 and 6 MPa uniformity was required for 30 and 50 mm windows respectively to achieve the mask overlay of less than 5 nm. Then we perform several experiments to optimize the sputtering conditions from the viewpoint of the geometric relation between a sputtering target and mask substrates. We observe that the target-substrate (T-S) distance in the axial direction changes only the average stress, but does not affect the uniformity, while the T-S distance in the parallel direction affects both the average and distribution. A very uniform stress absorber of ±3 MPa for a 25 mm square area is deposited 60 mm away from the target center. From further experiments, we establish a simple but important principle that the linear stress distribution on the stage deposited without rotation cancels out by rotating the substrate, and as a result the absorber stress becomes sufficiently uniform.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.36.7575
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1997
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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