A simplified process to fabricate high aspect ratio nanostructures in silicon combining electron beam lithography and deep reactive ion etching (DRIE) is presented. A stable process (HARSiN) has been developed without the need for complicated resist/hard mask processing or complex dry etch technologies. This is achieved using commercially available ZEP520A resist from Nippon Zeon Co., Ltd which...

Dry etching is an important process for micro- and nanofabrication. Sputtering effects can arise in two contexts within a dry-etch process. Incoming ions cause removal of volatile products that arise from the interaction between the dry-etch plasma and the surface to be etched. Also, the momentum transfer of an incoming ion can cause direct removal of the material to be etched, which is undesir...

In the fabrication of microstructures in SiO2 , etch selectivity of SiO2 to masking, etch stop, and underlayer materials need to be maintained at corners and inclined surfaces. The angular dependence of the SiO2-to-Si3N4 etch selectivity mechanism in a high density fluorocarbon plasma has been studied using V-groove structures. The SiO2 etch rate on 54.7° inclined surfaces is lower than on flat...

Reactive ion etching is a widely-used technique for fabricating via holes in polymer-metal multilayer interconnect structures. Reactive ion etching of thin film polymers was studied using Benzocyclobutene polymer and photoresist etch mask, in O2 and SF6 plasma. A design of experiments (DOE) was carried out with rf power, pressure, and SF6 concentration as the design variables, with a constant t...

We have investigated the optical properties of surface-micromachined polycrystalline silicon reflectors within the visible spectral range at five different wavelengths. The measurement results of the reflectivity of various microreflectors at four different incident angles (20 , 30 , 45 , and 60 ) are presented. Optical properties of microreflectors realized using the multiuser MEMS process (MU...

It is well established that the bulk etch rates for solid state nuclear track detectors are a ected by the concentration and the temperature of the etchant. Recently, we found that the bulk etch rate for the LR 115 detector to be a ected by stirring during etching. In the present work, the e ects of stirring on the bulk etch rate of the CR-39 detector is investigated. One set of sample was etch...

We demonstrate annealed low-temperature grown ~LTG! GaAs to be a highly effective etch-stop layer while photoetching n-type normal-growth-temperature GaAs. During this process, the etch rate is controlled by the transport of photogenerated carriers to the semiconductor/electrolyte interface. Because of the very short minority carrier lifetime in LTG-GaAs, only a very small portion of photogener...

A micromachined test structure was used to measure the etch rate of silicon in potassium hydroxide (KOH) as a function of surface orientation, which quantifies etchant anisotropy. By adding multidentate ligands, containing hydroxyl groups, to etchant solutions, the effects of these ligands on etch rate were determined. Bidentate ligands 1,2-ethanediol, 1,3-propanediol, and 1,4-butanediol each s...

The purpose of this study was to evaluate the effect of remaining dentin thickness (RDT) on the bond strength of current adhesive systems. Third molars were randomly allocated among four groups depending on the adhesive system used: Clearfil SE Bond ONE (SE1), G-Bond PLUS (GB), BeautiBond (BB), and Clearfil Mega Bond (MB). Bonded specimens were stored in water at 37°C for 24 h. Teeth were then ...