A flexible interconnection for integrated circuits

The semiconductor industry has developed at an unprecedented rate in the past two decades. Newer technology innovations have enabled the design of more complex structures. However, those IC chips are mostly fabricated on thick crystalline substrates and are not physically flexible. Flexibility of integrated circuits is very important in designing some devices such as small microprobes, sensors and disk drive flexible read/write assemblies. This thesis covers the study, analysis and fabrication of a flexible interconnection method for integrated circuits. Following standard processing steps of a commercial integrated circuit chip, an etching step is added to fabricate a flexible interconnection. This work starts with an investigation of a mechanical model in flexible interconnection design, which is a wide beam with applied moments. Theoretical calculations and tool simulations are provided to give a correct picture of bending an interconnecting membrane. The major focus of this work is the fabrication of the flexible interconnection, including etchant selection, photomask design and etching procedures. Anisotropic etchant TMAH is chosen to etch the silicon substrate. A special photomask is also designed for the fabrication. Several techniques, such as Silicon-On-Insulator, wafer lapping and Plasma Enhanced Chemical Vapor Deposition, are involved in this design to realize the interconnecting membrane. As a result, a sandwich-like membrane with silicon between silicon dioxide is obtained and proved flexible, which can be used as a flexible interconnection for integrated circuits. This flexible interconnection would be very useful for biomedical applications, such as small probes and devices. Because of its flexible characteristics, manufacture of some medical probes could be greatly simplified with this technique. Consequently, this will reduce the assembly cost of product and broaden the usage of the medical devices.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Electrical Engineering

Year dc:date.issued

1997

Author dc:creator

• Wang, Qingqi

Advisor dc:contributor.advisor

• Black, William C.

Language dc:language.iso

en

DOI

https://doi.org/10.31274/td-20250603-6

OAI identifier oai:identifier

oai:dr.lib.iastate.edu:20.500.12876/5w5pg6Rz