Sidewall doping

These processes are considerably more complex in actual CMOS fabrication. First, the lower layers of a CMOS stmcture typically have a twin-tub design which includes both PMOS and NMOS devices adjacent to each other (see Fig. 3b). After step 1, a mask is opened such that a wide area is implanted to form the -weU, followed by a similar procedure to create the -weU. Isolation between active areas is commonly provided by local oxidation of sihcon (LOCOS), which creates a thick field oxide. A narrow strip of lightly doped drain (LDD) is formed under the edges of the gate to prevent hot-carrier induced instabiUties. Passivation sidewalls are used as etch resists. A complete sequence of fabrication from wafer to packaged unit is shown in Figure 10. 

Figure 5.21 a shows an SEM micrograph (in cross section) of a feature ablated in doped PTFE, specifically 0.5% polyimide, at 12 J/cm2. The ablated feature is well defined and exhibits a smooth wall profile, typical of all blends having more than 0.1% (wt/wt) polyimide. The sidewall profiles of the less heavily doped blends are extremely vertical, having less taper than typically observed for more heavily doped PTFE films, e.g., 1.0 and 5.0% (Figures 5.21b and 5.21c, respectively) or Upilex-S polyimide, (Figure 5.21d). Ablation rates for a variety of PI-PTFE blends [0.2-5% polyimide (wt/wt) and neat polyimide] at 248 nm and 308 nm are shown in Figures 5.22 and 5.23, respectively.78...

We also predicted the possibility of chemisorption of carbon and oxygen atoms to the carbon nanotube sidewall. Oxygen atoms were ejected from the substrate after the collision of the argon atom beam with the silicon dioxide substrate. And when a carbon atom was effectively removed from the nanotube sidewall, it ended up doping the substrate or chemisorbed on other sector of the nanotube sidewall. We denoted chemisorption as the adsorption by covalent bonding of an atom to the nanotube sidewall. It could be considered the opposite of a vacancy defect. 

Fig. 7, Scanning electron micrographs (zoom-in series) of a sample with MBE-grown ZnO (material A) and Ga-doped ZnO (material B), processed using positive photoresist and wet-chemical etching. The wavy structures extending over the sample surface are remnants of the sputter coated ZnO layer that had been deposited on the resist sidewalls and hence were not removed in the lift-off step.

The problems with the poor inversion layer mobility in SiC can be addressed by using the ACCUFET structure shown in Fig. 13 (14). Here, the P-base region has been replaced with a very lightly doped N-region. If the spacing between the trench sidewalls is chosen so that the... 

The basic route of CP-CNT composite offers two paths, either the polymer functionalizes the CNTs or the CPs are doped with CNTs, i.e., a charge transfer occurs between the two constituents [13]. The main functionalization possibilities of CNTs are (A) generation and functionalization of defect sites at the tube ends and side walls by oxidation and subsequent conversion into derivatives (B) covalent sidewall functionalization using addition reactions and subsequent... 

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