Recently, the advent of MEMS and the ability to deposit thin film electronic devices on virtually any substrate has made many novel electronic, MEMS, microfluidic and biological devices possible. Examples of such devices would be in-situ thin-film electronic sensors and thin film transistors deposited in etched groves for detecting and controlling fluid flow in microfluidic and biological devices; neural reconnection using trenches etched in quartz or Si; electrical stimulation of nerve growth in trenches using in-situ deposited active devices; MEMS devices for sensing chemical pollutants, using ultra-thin piezoelectric membranes and selective receptor sites; DNA analysis using microchambers; implantable micropumps for drug delivery; Soi1CHIP for in-situ testing of soils; chemical lab on a chip etc. Most of these devices need the ability to etch deeply and controllably in a variety of substrates, such as Si wafers, polymers and quartz microplates. Some of the etching has to go ~100 micrometer deep.
At Iowa State University, and also at the PIs sister institution, the University of Iowa, a number of innovative projects are underway in this area which integrate electronic technology with biological and microfluidic technologies. Some of the noteworthy projects involve directed nerve regrowth in severed central nervous systems, using trenches in Si ,quartz or polymers to guide the direction of the regrowth; microfluidic channels for implantable micropumps; detection of trace chemicals for forensic testing using specialized chemical coatings on MEMS type structures; analytical laboratory on a chip; development of thin film transistors in deep trenches; development of nanocoatings for surfaces in MEMS type channels; measurement of structure and stress in cytoskeletons etc. All these projects need a deep reactive ion etching system. The one the PIs have stops at about 5 micrometer. In this project, they propose to purchase a versatile, laboratory-scale, deep uv reactive ion etching system from Oxford Instruments, which uses the patented Bosch process to achieve etching as deep as 100 micrometer. It is expected that this new system will allow them to successfully carry out some of the current and future projects in these very new and exciting fields of electro-biology, chemical MEMS, medical MEMS and opto-mechanical MEMS.
This instrument is capable of deep etching, using both Chlorine and Fluorine-based gases. The Oxford Instruments system is a proven lab-scale system, with a high density ICP plasma source, RE biasing of the substrate, capabilities for backside cooling of substrates and the provision for a load-lock. It is a cluster tool which can be added on to in later stages. It comes equipped with the appropriate flow controllers and corrosive service pumps. They propose to add to it, at their cost, an in-line high-resolution, computer-controlled optical emission spectroscopy (OES) system from Acton Research which will be very useful for understanding and controlling the different plasmas that one needs when etching quartz and polymers such as polyimide, PET and biological polymers.
This instrument will be housed at the Microelectronics Research Center(MRC) at Iowa State University. MRC is an interdisciplinary facility set up by Iowa State to provide research capabilities in the general area of semiconductors and MEMS for faculty and students from all departments. The PIs currently have students and faculty from EE, Materials Science and Engineering, ChemE, Physics, Chemistry, Mechanical Engineering, Industrial Engineering and Biology using MRC facilities extensively. They have many federally and industrially supported projects, and this new instrument will be useful to a wide group of faculty. Nearly 30 graduate students would benefit from having this instrument at MRC.
MRC has qualified, experienced, technicians available for installing and running this instrument. They have the necessary environmental monitoring and gas-disposal facilities required for such an instrument. And they have over 20 years of experience in running plasma reactors, including a PIE system, which unfortunately does not do deep etching.
The instrument will also help the PIs develop new courses in this area. They already have an extensive offering in the general semiconductor field, including several lab-based courses. They expect to add two inter-disciplinary course on plasma based manufacturing of electronic, MEMS and biological devices, and on measurement techniques if we get this instrument. Note that these courses will be open to both senior--level and graduate-level students. Thus, the educational impact will be felt both at undergraduate and graduate levels. The semiconductor and MEMS industries are very interested in having trained engineers in this field. So is the biomedical industry.
The PIs have planned an extensive outreach
