Functionalization of Semiconductor Surfaces

CHAPTER 12

Chemical Stability of Organic Monolayers Formed in Solution

LESLIE E. O'LEARY, ERIK JOHANSSON, AND NATHAN S. LEWIS

12.1 REACTIVITY OF H-TERMINATED SILICON SURFACES

12.1.1 Background

The H–Si surface is important to the electronics and photovoltaics industries because Si–H is the starting point for many Si-based devices. In turn, the electronic and chemical properties of the H-terminated Si surface affect the properties of subsequent Si surfaces and interfaces [1–3]. Dangling or weak bonds present at the surface will affect minority-carrier (“excited-state”) processes, and will thus affect devices such as field-effect transistors and photovoltaics. Furthermore, the topography of, as well as the presence of adsorbed chemical contaminants on, a H-terminated Si surface greatly affects the electronic properties of Si/SiO_x interfaces formed from this initial H-terminated Si surface [4,5]. Organic contaminants are difficult to remove from the Si surface, and different cleaning procedures have been shown to result in a variety of contaminant fingerprints. Hence, significant effort has been directed to understand the reactivity of the H–Si surface.

This section will explore the reactivity of the H-terminated Si surface with O₂, H₂O, alcohols, metals, amines, and thiols. The synthesis, as well as the physical and electronic characterization, of the H–Si surfaces will be reviewed briefly, but the reader is encouraged to consult Chapter 3 for a more detailed account of the preparation ...