Photostructuring Using the Modified Mask Method

7 Photostructuring Using the Modified Mask Method Principle 

The control over the depth of structures created in thick photoresists by varying the transmission of the mask used during the exposure has been used for the structuring of silicon for a few years [474]. This method was transferred to the photostructuring of UV-sensitive glass. 

The method is demonstrated using patterns of orthogonally crossed stripes or parallel stripes. Examples of successful structures in glasses are shown in Fig. 9.35. The parallel stripes pattern allows for better control of the structure because the depth of structures can be varied by enhancing the resolution of the stripes pattern. Therefore the parallel stripe design was used to examine the process parameters and for calculations. This will be described later in this section. 

The modification of the transmission of a mask allows for the production of three-dimensional structures in glass samples without undercuts. Some 

Variation of Parameters Controlling the Structuring Using Modified Masks 

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