Reflectance anisotropy spectroscopy (RAS) equipment is applied to monitor dry-etch processes (here specifically reactive ion etching (RIE)) of monocrystalline multilayered III-V semiconductors in situ. The related accuracy of etch depth control is better than 16 nm. Comparison with results of secondary ion mass spectrometry (SIMS) reveals a deviation of only about 4 nm in optimal cases. To illu...

(Oil) and (lll)B. This observation is consistent with the work of Coldren et a/. on the sensitivity of the etch rate of InP in HC1 to the crystal orientation. The profile in Fig. 2 was obtained using a mixture of 1(HC1): 3(H3POJ (again the grating orientation is (Oil)), In this case the profile is rectangular with a depth of c*2000 A. Here, the etched depth is not limited by the formation of in...

Being a low-cost, mass-production-compatible route to attain crystalline silicon, post-deposition crystallization of amorphous silicon has received intensive research interest. Here we report a low-temperature (300 °C), rapid (crystallization rate of ~17 nm/min) means of a-Si:H crystallization based on high-density hydrogen plasma. A model integrating the three processes of hydrogen insertion, ...

This study compared the effectiveness of an acid solution and an acid gel in etching the facial surfaces of primary anterior teeth. Comparisons included: (1) microscopic examination of the quality of etched enamel surfaces, (2) microscopic examination of the formation and penetration of resin tags into the etched surface, and (3) mechanical tests of the shear strength of the enamelresin bond. T...

The control of lateral mode operation using a photonic crystal in a vertical-cavity surface-emitting laser ~VCSEL! is analyzed and confirmed experimentally. By controlling design parameters of the photonic crystal pattern, we have produced photonic crystal VCSELs that operate in higher order defect modes in addition to the fundamental defect mode. The transverse modal behavior is consistent wit...

Placement of a restorative material in dentin produces the possibility of pulpal injury. In vitro studies have shown that the constituents of dental biomaterials have toxic potentials. In the clinical setting, there may be an immediate reaction of the pulp to, for example, acid etching and to the placement of a bonding agent; however, in most cases the remaining dentin serves as protection agai...

Porous silicon samples were prepared by electrochemical etching method for different etching times. The structural properties of porous silicon (PS) samples were determined from the Atomic Force Microscopy (AFM) measurements. The surface mean root square roughness (σ rms) changes as function of porosity were studied, and the influence of etching time on porosity and roughness was studied too. U...

This paper shows that the reflectance in silicon nanowires (SiNWs) can be optimized as a function of the area of silicon substrate where the nanostructure growth. SiNWs were fabricated over four different areas of silicon substrates to study the size effects using electroless etching technique. Three different etching solution concentrations of silver nitrate (AgNO3) and hydroflu...

This paper reports a high-throughput, label-free technique to visualize individual carbon nanotubes (CNTs) on a silicon wafer using a conventional optical microscope. We show that individual CNTs can locally enhance the rate of vapor-phase HF etching of SiO2 to produce a SiO2 trench that is several to several tens of nanometers in depth. The trench is visible under an optical microscope due to ...