Van Der Pauw Structures Research Articles

Analysis of symmetrical Van der Pauw structures with finite contacts

A theory is given for Van der Pauw structures with contacts of non-zero lengths which are invariant for rotations of 90°. A general theorem has been derived. For a certain class of structures an analytical solution of the Laplace equation is obtained instead of using finite difference equations. The method leans heavily on Schwarz-Christoffel transformation techniques.

An Experimental Study of Various Cross Sheet Resistor Test Structures

Newly designed cross sheet resistors are shown to give the same (within 0.5%) measured sheet resistance as conventional van der Pauw structures. Diffused boron and phosphorus layers with sheet resistances near 200 Ω/□ were studied with the sampled areas varying from a square 6.4 μm (0.25 mil) on a side to a circle 762 μm (30.0 mils) in diameter. An increase in measured sheet resistance values was observed due to surface leakage currents, and an equivalent circuit model was developed to explain the results. The effect of joule heating on measured sheet resistance values was observed in both large and small cross structures.