[...]... (8N), and the total number of occupied states remains 4N At the actual space of about 0.37 nm, however, the bands split again, exhibiting an energy gap Eg and a repartitioning of energy levels into 4N in the lower band (the valence band) and 4N in the upper band (the conduction band) The lower band is now filled with the 4N electrons and the upper band completely empty 1.3.2 Metals, Semiconductors and. .. energy band is the same as the number of states from which the band was formed Of primary interest for conduction are the uppermost two bands, the conduction band of quasi-free electron energy levels, and the band just below the conduction band, referred to as the valence band of bound electrons It will be shown that for silicon (and germanium) at crystal temperatures near absolute zero, the valence band... potential (V) hole Fermi potential (V) surface Fermi potential (V) silicon workfunction (V) surface neutrality level (V) electron affinity (V) stress (Pa) silicon electron affinity (V) List of Symbols χox ψ ψs ψs-field ω silicon- dioxide electron affinity (V) band-bending, potential (V) surface potential (V) surface potential under field oxide (V) angular frequency (s−1 ) xxv Chapter 1 Silicon Properties 1.1... electrons and holes (s) potential (V) dose (cm−2 ) pulsed-shaped implant dose (cm−2 ) barrier height (V) bulk Fermi potential (V) bulk electron Fermi potential (V) bulk hole Fermi potential (V) electron quasi Fermi potential (V) hole quasi Fermi potential (V) metal (gate) workfunction (V) workfunction difference between metal (gate) and Si (V) apparent metal (gate) workfunction (V) electron Fermi potential... from their bonds and move quasi freely in the crystal Hence, the number of quasi free electrons and holes (missing bond electrons) in the crystal increases as the temperature is increased The energy required to break a silicon bond is an ionization energy (∼1.1 eV) which differs from the ionization energy of an isolated silicon atom (∼8 eV) because B El-Kareh, Silicon Devices and Process Integration: Deep... example, Carbon 0 K, so the crystal behaves like an insulator What distinguishes silicon and germanium from carbon is the magnitude of the energy gap At near 0 K, the band-gap of germanium, silicon and carbon is, respectively, ∼0.74, ∼1.17 eV, and ∼5.48 eV When the bandgap is small, of the order of 1 eV, as for silicon and germanium, the crystal exhibits semiconductor properties (Fig 1.8c) In this case,... book, eV and cm are frequently used in place of J and m, as a convenient departure from SI units 1.2 Valence-Bond and Two-Carrier Concept 3 1.2.1 Doping Intrinsic silicon has very limited use in device applications since the conductivity is very low and conduction of electrons and holes essentially occurs in pairs One can, however, modify the type and magnitude of conductivity by adding small and controlled... Introduction A review of silicon properties is important to understanding silicon components, in particular modern components such as strained -silicon MOSFETs and heterojunction bipolar transistors Several books cover this subject in detail The objective of this chapter is to highlight those features that are most important to silicon device operation and characteristics 1.2 Valence-Bond and Two-Carrier Concept... are equal since they are generated and annihilated in pairs In this case, silicon is said to be intrinsic and n = p = ni cm−3 (1.1) n and p are the electron and hole concentrations, respectively, and ni the intrinsic carrier concentration (∼1.4 × 1010 cm−3 at 300 K) 1 One electron-Volt (eV) is the energy dissipated or acquired by one electron that goes through a potential difference of one Volt Since... missing A simplified one-dimensional representation of the energy bands relative to the periodic potential in the crystal is shown in Fig 1.6 It will be shown later that most of the transitions occur between the upper edge of the valence band and the lower edge of the conduction band In such situations only the edges of the conduction and valence bands are drawn, as indicated with dashed lines in Fig 1.5 A . h0" alt="" Silicon Devices and Process Integration Deep Submicron and Nano-Scale Technologies Badih El-Kareh Silicon Devices and Process Integration Deep. com- ponent matching and noise. Chapter 7 covers advanced enabling processes and process integration. It be- gins with integrated CMOS and BiCMOS processes to