Fabrication technologies - Micromixers Fundamentals Design and Fabrication - page 113

CHAPTER

4

Fabrication technologies

CHAPTER OUTLINE

4.1 Silicon-Based Microtechnologies .................................................................................................. 114
4.1.1 Basic technologies.....................................................................................................115
4.1.1.1 Photolithography....................................................................................................115
4.1.1.2 Chemical vapor deposition .....................................................................................116
4.1.1.3 Thermal oxidation ..................................................................................................116
4.1.1.4 Physical vapor deposition.......................................................................................117
4.1.1.5 Spin coating ..........................................................................................................118
4.1.2 Single-crystalline silicon ............................................................................................119
4.1.2.1 Wet etching ...........................................................................................................120
4.1.2.2 Dry etching............................................................................................................123
4.1.2.3 Bulk micromachined microchannels and nanochannels .........................................125
4.1.2.4 Epi-micromachining or near-surface micromachining .............................................127
4.1.3 Polysilicon ................................................................................................................128
4.1.3.1 Polysilicon surface micromachining........................................................................128
4.1.3.2 Fabrication of microchannels with silicon surface micromachining ..........................129
4.1.4 Other materials..........................................................................................................130
4.1.4.1 Diamond thin films ................................................................................................130
4.1.4.2 Silicon carbide.......................................................................................................131
4.2 Polymeric Microtechnologies........................................................................................................ 132
4.2.1 Thick-film polymeric materials ....................................................................................132
4.2.1.1 Polymethylmethacrylate (PMMA) resist ..................................................................132
4.2.1.2 SU-8 resist ............................................................................................................133
4.2.1.3 Other thick-film resists ...........................................................................................137
4.2.2 Polymeric bulk micromachining ..................................................................................137
4.2.2.1 Injection molding ...................................................................................................140
4.2.2.2 Hot embossing ......................................................................................................142
4.2.2.3 Soft lithography......................................................................................................142
4.2.2.4 Fast prototyping of micromixers with soft lithography ..............................................145
4.2.2.5 Laser machining ....................................................................................................146
4.2.3 Polymeric surface micromachining ..............................................................................147
4.2.3.1 SU-8 .....................................................................................................................147
4.2.3.2 Polyimide ..............................................................................................................148
4.2.3.3 Parylene................................................................................................................148