Polydimethylglutarimide (PMGI) as a structural material for surface micromachining

Abstract

This work investigates the use of polydimethylglutarimide, or PMGI, as a structural material for surface micromachining. PMGI is a commercially available, positive-toned deep-UV resist designed for use in bi-layer lift-off techniques. This paper presents a technique for the microfabrication of free-standing PMGI structures, and uses those structures to extract the coefficient of thermal expansion and Young's modulus for PMGI. Our study found PMGI's coefficient of thermal expansion to be 56 ± 6 ppm • C −1 and Young's modulus to be 5.0 ± 0.5 GPa. Active structures were also fabricated by including a patterned metal layer. This allows the fabrication of active devices, such as bent-beam actuators. PMGI is a commercially available polymer being used in micromachining, and this paper provides the first report of its thermo-mechanical properties.

Fabrication of precisely aligned microwire and microchannel structures: Toward heat stimulation of guided neurites in neuronal cultures

“…Moreover, the LOR30B resist is based on poly‐dimethylglutarimide (PMGI), a deep‐UV positive resist, used mainly for bilayer lift‐off processes. PMGI is a good sacrificial layer candidate compatible with SU‐8 . It complies with a variety of thicknesses and has a glass transition temperature of 190 °C, which is greater than the processing temperatures required for SU‐8 .…”

“…PMGI is a good sacrificial layer candidate compatible with SU‐8 . It complies with a variety of thicknesses and has a glass transition temperature of 190 °C, which is greater than the processing temperatures required for SU‐8 . Thus, the resist is compatible with the post‐bake and development process of SU‐8 due to its high thermal and chemical stability.…”

Exposure and development of thick polydimethylglutarimide films for MEMS applications using 254-nm irradiation

“…[5][6][7][8][9][10] We have also begun investigating PMGI use as a structural MEMS material for surface micromachining. 11 PMGI-based resists are positive-toned and can be patterned using deep-UV ͑DUV͒ radiation. PMGI has also been patterned using electron-beam 5,6 and proton beam exposure.…”

Isopropanol/water as a developer for poly(dimethylglutarimide)

“…For example, PMGI can be used to create lift-off profiles with thicknesses greater than 10 m. 8 In addition to being used as a resist, PMGI has also been used as an optical material in microfabricated optical devices [15][16][17] and as both a structural layer and a sacrificial layer in surface micromachining. [18][19][20][21] Depending on the formulation, PMGI has a glasstransition temperature of approximately 190°C. 10,17,19 However, it is thermally stable to temperatures over 300°C.…”