## 1 Introduction  
Hydroosilylation on silicon surface remains a relatively useful technique for the passivation of silicon surface with organic monolayers but the process is extremely sensitive towards water contamination due to the susceptibility of water molecules reacting with surface radicals [1; 2; 3]. On the other hand, thermal-based hydrosilylation is another alternative that works at higher temperature (150-200 \({}^{\circ}\)C) that may ensure that water within from solvent is kept minimal to reduce the chances of oxidation. Recent models of thermal reactions do suggest that the surface reaction to form a stable Si-C linkage can proceed at lower temperatures (<150 \({}^{\circ}\)C) as reported by [PERSON] et al. [4] but at these lower temperatures, hydrogenated silicon surface can also be prone to nucleophilic reactions [5; 6]. Of these, surface reaction between alcohol and hydrogenated Silicon (Si-H) was well established in literature and many other reports had shown the formation of stable Si-O-C linkage towards the surface [7; 8; 9; 10].  
Nonetheless, the exact mechanism for thermal hydrosilylation had remained relatively elusive for several reasons. To begin with, it is important to consider the issue of steric hindrance for [PERSON] et al. simply stated that a full passivation cannot be attained due to the proximity of the silicon adatoms [11; 12]. It was also increasingly clear that even at temperatures above 150 \({}^{\circ}\)C, the nominal silicon hydride hemolysis may not be the initiating process on silicon surfaces as described by [PERSON] et al. and there might be the contention of surface silicon dimerization, especially in ultra high vacuum conditions [13]. However, such a description may not be fully accepted within the scientific community currently. With regards to UV photoionization, the process has also been under some scrutiny in recent years with the notion of excitons taking main stage of the underlying process [14; 15]. Hence, the need to elicit the exact silicon surface reactivity under the various conditions remains relatively pressing despite the huge stride made in literature. Yet, it was noticeable that a majority of research did not take into account the nature of the doping together in conjunction with crystal lattice type. However, it has to be said that some inroads were made by [PERSON] et al. using visible light passivation on silicon (111) and (100) surfaces [16]. Overall, the link between these physical attributes and how they may ultimately influence surface reaction outcome has remained relatively obscure.  
Previously, our group has also demonstrated the preference of hydrogenated silicon towards nucleophilic additions with alcohol ends of alkynes [6; 17; 18]. In fact, many reports have shown the susceptibility of alcohol grafting on silicon-hydride surfaces [4; 7]. Upon the formation of the Si-O-C bond, studies showed that the presence of water could induce surface roughening but what is more interesting is that roughening proceeds differently depending on the doping of the silicon substrate. As reported by [PERSON] et al. [7], boron doped \(p\)-type silicon was observed to develop an overall rougher surface while in \(n\)-type samples roughening is generally localized along the step edges of atomically flat terraces [8]. Basically, while the description for this phenomenon has always been depicted as being due to 'water contamination', the underlying topographical differences may suggest an even richer underlying chemistry. Therefore, to further understand this chemistry, we examined the resultant surfaces upon functionalization with alcohol on both \(p\)- and \(n\)-type silicon at comparable doping levels as well as of two different crystal orientations, (111) and (100). The aims of this work are to attempt to establish a tangible link between crystal orientation as well as doping nature and this report suggests that these effects may be manifest to subtly influence the outcome of the alcohol grafting.