Reactive-ion etching | EPFL Graph Search

Reactive-ion etching (RIE) is an etching technology used in microfabrication. RIE is a type of dry etching which has different characteristics than wet etching. RIE uses chemically reactive plasma to remove material deposited on wafers. The plasma is generated under low pressure (vacuum) by an electromagnetic field. High-energy ions from the plasma attack the wafer surface and react with it. Equipment A typical (parallel plate) RIE system consists of a cylindrical vacuum chamber, with a wafer platter situated in the bottom portion of the chamber. The wafer platter is electrically isolated from the rest of the chamber. Gas enters through small inlets in the top of the chamber, and exits to the vacuum pump system through the bottom. The types and amount of gas used vary depending upon the etch process; for instance, sulfur hexafluoride is commonly used for etching silicon. Gas pressure is typically maintained in a range between a few millitorr and a few hundred millitorr by

Shining Diamond: from Micro- and Nano-Engineering to Quantum Photonics

Sichen Mi

The discovery of room-temperature single photon emission from color centers in diamond has in recent years boosted research interest in this renowned material in photonics and quantum community and beyond. Following understanding some basic principles of how the color centers work, new challenges arose: designing and fabricating real devices that leverage the unrivaled properties that diamond possesses. Due to this material's extreme physical hardness and its chemical resistance to etchants, the established semiconductor technologies cannot straightforwardly answer to the call for scalable and reliable fabrication of micro- and nano-photonic devices in single crystal diamond. In this thesis, we first demonstrate an unconventional polishing protocol with ion beam etching, which makes possible wafer-scale fine finishing of diamond substrates, the starting point for any subsequent processing. Following this we present the experimental observation of self-organized nanotextures on diamond induced by ion beam irradiation, a lithography-free approach for nanoengineering periodic structures. Regarding device fabrication, we obtained free-standing micro- and nano-photonic structures using angled reactive ion etching, facilitated by a novel and reproducible Faraday cage design. We also propose possible designs to interconnect individual components in hope of realizing a photonic integrated circuit in the future. Last but not least, we present spectroscopic characterization of single and ensemble color centers either grown by microwave plasma chemical vapor deposition, or fabricated by ion implantation with subsequent high-temperature annealing, which are the fundamental building blocks for quantum applications. Photoluminescence spectra that, to our knowledge, are not seen in literature were recorded for ensemble silicon-vacancy centers at cryogenic temperature, signifying potentially unknown mechanism for tuning the optical transitions, and unexplored possibilities with this exciting material platform for quantum technologies.

EPFL2021

Development of novel SU-8 based nanoimprint lithography

Shenqi Xie, Rong Yang

We present two kinds of novel nanoimprint lithography techniques based on SU-8 photoresist with single layer and tri-layer approaches. The imprint templates with high aspect ratio were first fabricated by electron beam lithography (EBL) and reactive ion etch (RIE), and then duplicated by the SU-8/SiO2/PMMA tri-layer technique we developed. Imprint properties such as pressure and temperature are determined to fabricate different nanostructures with various imprint depth. The developed processes, which provide us the capability to fabricate both imprinted nanostructures on resist and transferred nanopatterns on substrate with high volume and low cost, are further applied in producing high density gratings, planar chiral photonic metamaterials, and nanofluidics channels.

2008

Shining Diamond: from Micro- and Nano-Engineering to Quantum Photonics

Sichen Mi

EPFL2021