Abstract: In this paper, a DRIE process for fabricating MEMS silicon trenches with a depth of more than 250 m is described. The DRIE was produced in oxygen-added sulfur hexafluoride (SF6) plasma, with sample cooling to cryogenic temperature using a Plasmalab System 100 ICP 180 at different RF powers. A series of experiments were performed to determine the etch rate and selectivity of the some m...

microfabrication applications, it is widely used to transfer the designed patterns from an etching mask to the substrate. When the sample is immersed into the etching bath, the etchant only contacts and reacts with the substrate surfaces where are uncovered by the etching mask. The suitable materials for the mask can be polymers or other materials such as photoresist, SU-8,SiO2 andSi3N4, which ...

The effects of HF/NH4F, wet chemical etching on the morphology of individual surface fractures (indentations, scratches) and of an ensemble of surface fractures (ground surfaces) on fused silica glass has been characterized. For the individual surface fractures, a series of static or dynamic (sliding) Vickers and Brinnell indenters were used to create radial, lateral, Hertzian cone and trailing...

The fabrication of the 2D GaN-based photonic crystal structure at optical scales, a subμm scale in our case is very challenging. In our work, a double-etching method proved to be feasible to achieve the periodic GaN/air variation. The pattern was defined in a PMMA resist by electron-beam lithography and transferred to SiO2 by reactive ion etching (RIE) in a CF4 plasma and further into GaN by RI...

The synchrotron radiation (SR) stimulated etching of silicon elastomer polydimethylsiloxane (PDMS) using XeF(2) as an etching gas has been demonstrated. An etching system with differential pumps and two parabolic focusing mirrors was constructed to perform the etching. The PDMS was found to be effectively etched by the SR irradiation under the XeF(2) gas flow, and the etching process was area-s...

When etching high-aspect-ratio silicon features using deep reactive ion etching DRIE , researchers find that there is a maximum achievable aspect ratio, which we define as the critical aspect ratio, of an etched silicon trench using a DRIE process. At this critical aspect ratio, the apparent etch rate defined as the total depth etched divided by the total elapsed time no longer monotonically de...

The optimization of etchant parameters in wet etching plays an important role in the fabrication of semiconductor devices. Wet etching of tetramethylammonium hydroxide (TMAH)/isopropyl alcohol (IPA) on silicon nanowires fabricated by AFM lithography is studied herein. TMAH (25 wt %) with different IPA concentrations (0, 10, 20, and 30 vol %) and etching time durations (30, 40, and 50 s) were in...

Using an SPTS Technologies Ltd. Pegasus deep reactive-ion etching (DRIE) system, an advanced two-step etching process has been developed for hollow microneedles in applications of transdermal blood sampling and drug delivery. Because of the different etching requirements of both narrow deep hollow and large open cavity, hollow etch and cavity etch steps have been achieved separately. This novel...