2-2. Ohmic contact (Ohmic junction) Φ_m < Φ_n

Let the work function of a metal be Φ_m and that of an n-type semiconductor be Φ_n. When Φ_m < Φ_n, an ohmic junction is formed when the semiconductor is in contact with the metal.
Figure 2-4 shows the band diagram of an ohmic junction formed by an n-type semiconductor and a metal. The ohmic junction has no diffusion barrier. Therefore, application of external voltage causes current to flow regardless of its polarity. Unlike the Schottky junction, the ohmic junction does not exhibit diode-like rectifying properties. For example, the ohmic junction is used for bonding pads on a semiconductor chip to create interconnections with its package.