Geometrical Photostructuring

Stookey [497,498] was the first to publish the complete photostructuring process under the name Chemical Machiningor Sculpturingdescribing a suitable glass composition, the principle of the process and optimum processing conditions as well as first applications. This process was further developed over the years ([227, 399]). A new description of the photostructuring process and new results can be found in the literature [190, 446].

Geometrical photostructuring requires special, photostructurable glasses of the Li2O–Al2O3–SiO2 system containing several dopants. These glass compositions and photochemically induced compositional changes are described in detail in Sect. 1.2.4.

The standard structuring process is based on photolithography and consists of three main steps UV exposure, thermal treatment and acid etching. A schematic of the process is shown in Fig. 9.1. The following discussion focuses on the photostructurable glass FS21 developed at the Technische Universität Ilmenau.