Electrons passive

However, if the molecules of 5 had R alkyl chains longer than Me, the steric hindrance prevented 100% substitution and IR examinations indicated a 50% less derivatization. Moreover, XPS analysis showed that the surface is partly modified by substitution of hydrogen by halogen . In the case of 5 with X = I and to some extent X = Br, the formation of X radicals (besides 12) in a secondary reaction was reported . They participate in reactions analogous to equations 21 and 22b, but with X instead of 12, and attach to the Si surface improving the electronic passivation of the surface at defect sites, sterically inaccessible to 12. A possibility that surface dangling bonds may also appear in the charged states was discussed as well . 

For the case of integrated circuit technology there are other very important uses for preparing SiC on Si. It is clear that the electronic passivation is the most important and fundamental use for SiC and that the other uses to be discussed are bonuses, and in many instances could be accomplished equally well and sometimes better with other materials and other processes than SiC and oxidation. 

If we consider the physical properties of SiO itself, then several of the other uses become obvious. SiO is a wide band gap insulator (about 9eV). As such, the electrical influence of SiOz on the conduction process on the Si surface is nil except for the reduction of the dangling bonds as discussed above. Thus one obtains the electronic passivation without any troublesome interference. The SiC film, being a good insulator, will be able to support a rather large electric field (greater than 10 V/cm). Such an electric field applied across the oxide film will alter the Si surface potential and thereby modulate the conduction of carriers in conductive channels created at the Si surface. This effect is the operational principle for the field effect... 

C. J. Sandroff et al.. Electronic Passivation of GaAs Surfaces Through the Eormation of Arsenic - Sulfur Bonds, Appl. Phys. Lett. 1989, 54(4), 362-364. 

As stated in the introduction, chemical and electronic passivation of III-V. semiconductor surfaces is an important technological process and has given rise to much pure and applied research 52,5.3. O2 itself is a very inefficient passivating agent for GaAs an exposure of up to 10 L is needed to form a substantial... 

Si02 films could be applied onto the Si surface with many techniques to fulfil the surface electronic passivation purpose. However, a comparison of the different ways to prepare Si02 on Si (CVD, PVD and thermal oxidation)... 

The process of GaAs oxidation is so complex that even after many years of work there are important issues that are still a matter of controversy. Consequently, the GaAs metal insulator semiconductor field effect transistor (MISEET) technology did not develop very weU since the electronic passivation of GaAs is not fully resolved. The challenges in the fabrication of high quality oxide layers on GaAs stimulate researchers to find out the most suitable techniques and conditions to solve the interface-related problems. 

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