Recent Advances in Reactive Ion Etching and Applications of High-Aspect-Ratio Microfabrication

Abstract

This paper reviews the recent advances in reaction-ion etching (RIE) for application in high-aspect-ratio microfabrication. High-aspect-ratio etching of materials used in micro- and nanofabrication has become a very important enabling technology particularly for bulk micromachining applications, but increasingly also for mainstream integrated circuit technology such as three-dimensional multi-functional systems integration. The characteristics of traditional RIE allow for high levels of anisotropy compared to competing technologies, which is important in microsystems device fabrication for a number of reasons, primarily because it allows the resultant device dimensions to be more accurately and precisely controlled. This directly leads to a reduction in development costs as well as improved production yields. Nevertheless, traditional RIE was limited to moderate etch depths (e.g., a few microns). More recent developments in newer RIE methods and equipment have enabled considerably deeper etches and higher aspect ratios compared to traditional RIE methods and have revolutionized bulk micromachining technologies. The most widely known of these technologies is called the inductively-coupled plasma (ICP) deep reactive ion etching (DRIE) and this has become a mainstay for development and production of silicon-based micro- and nano-machined devices. This paper will review deep high-aspect-ratio reactive ion etching technologies for silicon, fused silica (quartz), glass, silicon carbide, compound semiconductors and piezoelectric materials.

A Review: Inductively Coupled Plasma Reactive Ion Etching of Silicon Carbide

“…RIE process itself is also very useful for high-aspect-ratio profiles. Recent advances in reactive ion etching for application in high-aspect-ratio microfabrication have been presented by Huff [ 26 ].…”

Integration of Multifocal Microlens Array on Silicon Microcantilever via Femtosecond-Laser-Assisted Etching Technology

“…This is because the principle of dry etching involves using the plasma of chemical gas to produce a chemical reaction, and accelerate physical etching and chemical etching through an electric field, so the etching is isotropic. It should be mentioned that by changing the etching gas in the cycle during the etching process, high-aspect-ratio silicon microstructures can be realized [39,40]. Therefore, different patterned silicon-based microlens arrays can be prepared using this method.…”

Perspectives of reactive ion etching of silicate glasses for optical microsystems

“…In low-pressure plasmas, the directionality of ion bombardment causes a preferred removal at vertical incidence (bottom), whereas a sidewall polymer layer inhibits the lateral etching of the material. 40 Thus, surfaces oriented perpendicular to the ion incidence usually show a higher etch rate than the sidewalls of the structures. 41 The overall etching is defined by the amount of chemically active species in the plasma, their diffusion onto the substrate surface and the flux, the angular distribution, and the kinetic energy of the positive ions accelerated to the substrate surface.…”