Abstract: The energy levels of a Ge/Si quantum well were obtained by solving the Schordinger equation based on the finite potential well approximation.For the quantum well structure,the characteristics of capacitance-voltage (C-V) and the distribution of carrier concentration were derived in different bias voltage regions by analytically solving Poisson’s equation.The appearance of a capacitance platform is a distinct characteristic of the C-V curve for quantum well structures,which is relative to the structure parameter of the quantum well.As the thickness of capping layer decreases,the starting capacitance of the C-V platform increases and shifts toward low reverse bias.As the doping concentration in the quantum well or the capping layer increases,a high reverse bias is needed to exhaust the carriers in the quantum well,and the platform width increases.The apparent carrier concentration distribution in the quantum well can be obtained from the C-V curve.

Key words: Ge/Si quantum-well, C-V characteristics, iterative method