TY - JOUR

T1 - Viscoelastic deformation of borosilicate glass substrates induced by a laser-patterned silicon suboxide film

AU - Fütterer, Laura

AU - Beckmann, Clemens M.

AU - Ihlemann, Jürgen

N1 - Funding Information: Financial support was received from Bundesministerium für Wirtschaft und Energie and Niedersächsisches Ministerium für Wissenschaft und Kultur under grant number 03THW05K09. Funding Information: The authors would like to thank Lukas Janos Richter (IFNANO) for deposition of the silicon suboxide films, Andreas Röben (IFNANO) for performing the wavefront measurement, and Matthias Kulp (Max-Planck-Institut für Multidisziplinäre Naturwissenschaften) for preparation of the N-BK7 substrates.

PY - 2023/2

Y1 - 2023/2

N2 - In general, a thin film deposited on a substrate surface exhibits a certain amount of stress that causes a deformation of the substrate. Usually, the deformation is elastic, however, under some circumstances, a non-recoverable deformation of the substrate can be observed. Recently, we demonstrated that a large non-recoverable deformation of fused silica substrates can be obtained if on one side a film of substoichiometric silicon oxide is deposited and the film-substrate system is annealed at a temperature in the glass transition range. By laser patterning of the film, specific surface shapes can be obtained. Here, we report on a similar approach for the viscoelastic deformation of plates of borosilicate glass (Schott N-BK7). The substrates are coated by a film of substoichiometric silicon oxide, which is patterned by application of a XeCl-excimer laser. We measured the surface shape of the non-coated side after different annealing durations. Deformation of the samples corresponds to a tensile film stress. But by application of a line pattern, toroid surface shapes with curvatures of different sign can be easily obtained. With further investigation and development, the process might be applied for production of freeform surfaces.

AB - In general, a thin film deposited on a substrate surface exhibits a certain amount of stress that causes a deformation of the substrate. Usually, the deformation is elastic, however, under some circumstances, a non-recoverable deformation of the substrate can be observed. Recently, we demonstrated that a large non-recoverable deformation of fused silica substrates can be obtained if on one side a film of substoichiometric silicon oxide is deposited and the film-substrate system is annealed at a temperature in the glass transition range. By laser patterning of the film, specific surface shapes can be obtained. Here, we report on a similar approach for the viscoelastic deformation of plates of borosilicate glass (Schott N-BK7). The substrates are coated by a film of substoichiometric silicon oxide, which is patterned by application of a XeCl-excimer laser. We measured the surface shape of the non-coated side after different annealing durations. Deformation of the samples corresponds to a tensile film stress. But by application of a line pattern, toroid surface shapes with curvatures of different sign can be easily obtained. With further investigation and development, the process might be applied for production of freeform surfaces.

KW - Freeform surface

KW - Glass

KW - Laser ablation

KW - Stress figuring

KW - Thin film

KW - Viscoelastic deformation

UR - http://www.scopus.com/inward/record.url?scp=85146298140&partnerID=8YFLogxK

U2 - 10.1007/s00339-022-06357-4

DO - 10.1007/s00339-022-06357-4

M3 - Article

AN - SCOPUS:85146298140

VL - 129

JO - Applied Physics A: Materials Science and Processing

JF - Applied Physics A: Materials Science and Processing

SN - 0947-8396

IS - 2

M1 - 107

ER -