Nonuniform Dopant Distribution Research Articles

Magnetic susceptibility of iodine doped polyacetylene: The effects of nonuniform doping

A detailed study of magnetic properties of [CHH(I 3) y] x demonstrates that with quasi-uniform doping, the spin susceptibility is small, consistent with the soliton doping mechanism. Traditional doping techniques lead to one order of magnitude larger spin susceptibilities, and to a nonuniform dopant distribution. We present a simple model which accounts for the observed susceptibility based on the effect of a radial variation of y within the (CH) x fibrils.

A Doped Surface Two-Phase CCD

The successful operation of an n-channel two-phase charge-coupled device has been achieved. The asymmetry in the surface potential profile necessary to force the charge to move unidirectionally was obtained by ion implanting a nonuniform doping distribution in the Si substrate under each gate. An eight-stage shift register with a length per stage of 80 µm was made, and was operated as both a digital and an analog device. There are two ways to clock the device. Either both clock lines are driven with square waves, out of phase by one half of a period, or one clock is held at a fixed DC potential while the other is driven with a square wave. Using the latter method, the charge transfer efficiency was better than 99.9 percent per transfer over the clock frequency range of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> Hz to 6.5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> Hz.

Numerical corrections for Hall effect measurements in silicon containing Gaussian dopant distributions

Hall effect and conductivity measurements in semiconductor samples containing nonuniform dopant distributions are related to bulk carrier densities and mobilities in a complex manner depending upon the carrier distribution. In this paper numerical factors for Gaussian distributions in silicon are presented to correct measured values of areal carrier density and average mobility to true values. The error in neglecting these corrections is shown to be less than 18 per cent for electrons and 12 per cent for holes. In addition, the error becomes negligible in the limits of very light or very heavy doping.