Thick resist for MEMS processing

Brown, Joe; Hamel, Clifford

doi:10.1117/12.448985

Cited by 2 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These reports include the characterization of the DNQ photoresist property [33][34][35][36][37], photolithography simulation models [38][39][40][41][42][43][44][45][46][47][48], and so on. In the past few years, a growing number of research groups reported the DNQ photoresist as a thick photoresist for MEMS applications [49][50][51][52][53][54][55][56][57][58][59]. However, compared to the previously reported studies of the DNQ photoresist with thickness of less than 25 μm, the number of publications on 3D thick-photoresist microstructures using more than 25 μm thickness and its detail experimental study is very limited [20,60].…”

Section: Introductionmentioning

confidence: 99%

A three-dimensional microstructuring technique exploiting the positive photoresist property

Hirai¹,

Sugano

Tsuchiya

et al. 2010

J. Micromech. Microeng.

View full text Add to dashboard Cite

The present paper describes a three-dimensional (3D) thick-photoresist microstructuring technique that exploits the effect of exposure wavelength on dissolution rate distributions in a thick-film diazonaphthoquinone (DNQ) photoresist. In fabricating 3D microstructure with specific applications, it is important to control the spatial dissolution rate distribution in the photoresist layer, since the lithographic performance for 3D microstructuring is largely determined by the details of the dissolution property. To achieve this goal, the effect of exposure wavelength on dissolution rate distributions was applied for 3D microstructuring. The parametric experimental results demonstrated (1) the advantages of the fabrication technique for 3D microstructuring and (2) the necessity of a dedicated simulation approach based on the measured thick-photoresist property for further verification. Thus, a simple and practical photolithography simulation model that makes use of the Fresnel diffraction theory and an empirically characterized DNQ photoresist property was adopted. Simulations revealed good quantitative agreement between the photoresist development profiles of the standard photolithography and the moving-mask UV lithography process. The simulation and experimental results conclude that the g-line (λ = 436 nm) process can reduce the dimensional limitation or complexity of the photolithography process for the 3D microstructuring which leads to nanoscale microstructuring.

show abstract

Section: Introductionmentioning

confidence: 99%

A three-dimensional microstructuring technique exploiting the positive photoresist property

Hirai¹,

Sugano

Tsuchiya

et al. 2010

J. Micromech. Microeng.

View full text Add to dashboard Cite

show abstract

Laser lithographic approach to micro-optical freeform elements with extremely large sag heights

et al. 2012

View full text Add to dashboard Cite

Artificial compound eye cameras are an attractive approach to generate imaging systems of maximum miniaturization. Their thickness can be reduced by a factor of two in comparison to miniaturized single aperture cameras with the same pixel size and resolution. The imaging performance of these systems can be improved significantly by the use of micro-optical refractive freeform arrays (RFFA). Due to the complexity of these non-symmetric surface profiles with sag heights larger than 50 µm in combination with extreme profile accuracies better than λ/14 (rms), there is no dedicated fabrication technology currently available. In the presented research, significant improvements in the fabrication of these elements with laser lithography were reached. Therefore, a laser lithographic process based on several coating steps in combination with a multiple exposure strategy was developed that is suitable for the fabrication of arbitrary freeform structures with sag heights up to 60 µm. In order to minimize surface deviations caused by unavoidable process nonlinearities, a compensation strategy based on an empirical process model is used. The achievable accuracy of the proposed method and its limitations were investigated by fabricating a spherical micro lens array for demonstration. The fabricated elements possess a shape deviation of less than 1.3 µm (rms) and can be used as master structures for a subsequent replication process in order to realize a cost efficient mass production of artificial compound eye optics on wafer level.

show abstract

Thick resist for MEMS processing

Cited by 2 publications

References 0 publications

A three-dimensional microstructuring technique exploiting the positive photoresist property

A three-dimensional microstructuring technique exploiting the positive photoresist property

Laser lithographic approach to micro-optical freeform elements with extremely large sag heights

Contact Info

Product

Resources

About