Silicon hydrogen adsorbed

Tanielian, M. Fritzsche, H Tsai, C C Symbalisty, E. (1978). Effect of adsorbed gases on the conductance of amorphous films of semiconductor silicon-hydrogen alloys, Appl. Phys. Lett., Vol. 33,353 -356, ISSN 0003-6951... 

Robertson has summarized the three recent classes of models of a-Si H deposition [439]. In the first one, proposed by Ganguly and Matsuda [399, 440], the adsorbed SiHa radical reacts with the hydrogen-terminated silicon surface by abstraction or addition, which creates and removes dangling bonds. They further argue that these reactions determine the bulk dangling bond density, as the surface dangling bonds are buried by deposition of subsequent layers to become bulk defects. 

Beton and co-workers extended the hydrogen bonding approach to two-component systems, generating a number of structures that utilise different molecular motifs.24 26 In the case of perylene tetracarboxylic diimide (PTCDI) co-adsorbed with melamine (1,3,5-triazine-2,4,6-triamine) on a silver-terminated silicon surface, a network is formed in which the straight edges correspond to PTCDI with melamine at the vertices (Figure 11.6). The network shows large-area pores that the authors used to trap heptamers of C6o molecules. 

Brenner and Garrison introduced a potential which was derived by rewriting a valence force expression so that proper dissociation behavior is attained . Because the equations were extended from a set of terms which provided an excellent fit to the vibrational properties of silicon, this potential is well suited for studying processes which depend on dynamic properties of crystalline silicon. For example, Agrawal et al. have studied energy transfer from adsorbed hydrogen atoms into the surface using this potential . 

There are countless examples of the interactions of various atoms and molecules with the clean Si(100) surface. In addition these adsorbate-surface interactions can differ with deposition conditions, such as the rate of deposition or temperature of the sample. For example, even the simplest adsorbate, hydrogen, can etch the surface at room temperature and also form a variety of ordered structures at elevated sample temperatures [57]. A number of adsorbates can form ordered structures commensurate with the surface (e.g. Ag [58], Ga [59], Bi [60]), most transition metals react with the surface to form silicides (e.g. Ni [61], Co [62], Er [63]), halogens can etch the surface at room temperature (e.g. F2 [64], CI2 [65], Br2 [66]), some molecules dissociate on the surface (e.g. PH3 [67], B2H6 [68], NH3 [37]) and other molecules can bond to the silicon in different adsorption configurations but remain intact (e.g. Benzene [69], Cu-phthalocyanine [70], C60 [71]). A detailed review of a number of adsorbate-Si(lOO) interactions can be found in [23,72] and a more specific review relating to organic adsorbates can be found in [22]. As an example of an adsorbate-silicon system we shall here consider the adsorption of a molecule that our group has extensive experience with phosphine. 

Some examples of molecular adsorbates on the patterned hydrogen terminated silicon surface are shown in Fig. 13. Perhaps the most notable for... 

---