Direct etched pattern

Once the resist has been patterned, the selected regions of material not protected by photoresist are removed by specially designed etchants, creating the resonator pattern in the wafer. Several isotropic (etching occurs in all directions at the same etch rate) and anisotropic (directional) etching processes are available. Wet chemical etching is an isotropic process that... 

Fig. 15.13 shows a bonding map for silicon wafer bonding combinations of topography and spatial wavelength that fall below the traces will bond those above the traces will produce voids [101]. This and further work by Turner et al. have explored parameters for direct wafer bonding under clamped conditions [107], addressed wafer bow and etch pattern considerations [108], as well as nanoscale roughness considerations [101]. This work shows that... 

Turner K, Spearing S. Modeling of direct wafer bonding effect of wafer bow and etch patterns. J Appl Phys 2002 92(12) 7658-7666. 

The only system that employs the direct mode for semiconductor etching was reported by Lin et al. (3). n-GaAs was photoetched by holding a sharp metallic tip, insulated in glass, in close proximity (<1 /xm) to a positively biased (4 V) n-GaAs while illuminating the substrate. The formation of etched patterns with line widths of 0.3-2 /xm was attributed to the nonuniform spatial current distribution. Nonetheless, some etching also occurred across the whole surface because there was no attempt to focus the illumination on the area beneath the UME. 

S. Chattopadhyay and P. W. Bohn, Direct-write patterning of microstructured porous silicon arrays by focused-ion-beam Pt deposition and metal-assisted electroless etching, J. Appl. Phys. 96, 6888-6894 (2004). 

Figure 20. Ai gon laser etched patterns on the order of 1 urn width toy direct scanning. A lew magnification image is shown in (a) and a high magnification image in (to). The surface rou mess is produced toy the debris deposited cxi the surface during the etching process.

Chattopadhyay S, Bohn PW (2004) Direct-write patterning of microstructured porous silicon arrays by focused-ion-beam Pt deposition and metal-assisted electroless etching. J Appl Phys 96 6888 Chattopadhyay S, Bohn PW (2006) Surfactant-induced modulation of light emission in porous silicon produced by metal-assisted electroless etching. Anal Chem 78(17) 6058-6064 Chattopadhyay S, Li X, Bohn PW (2002) In-plane control of morphology and tunable photoluminescence in porous silicon produced by metal-assisted electroless chemical etching. J Appl Phys 91 6134-6140... 

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