Abstract: Sheet resistance, junction leakage and contact conductivity of a semiconductor layer, associated with an ultra-shallow junction layer or metal film are measured by contacting the surface with a plurality of probes. The probes can be used, in conjunction with a four-point probe system, to determine sheet resistivity. Junction leakage through an ultra-shallow junction is determined by establishing a reverse bias across the junction set at a predetermined voltage value, measuring through a first probe a total junction current conduction value, measuring through second, third, and fourth probes a plurality of voltage values. The junction leakage value is then directly computed based on the sheet resistivity value, reverse bias potential, wafer radius, and the measured voltage values. Contact conductivity between a metal film and semiconductor layer can be similarly directly computed.

Abstract: Sheet resistance, junction leakage and contact conductivity of a semiconductor layer, associated with an ultra-shallow junction layer or metal film are measured by contacting the surface with a plurality of probes. The probes can be used, in conjunction with a four-point probe system, to determine sheet resistivity. Junction leakage through an ultra-shallow junction is determined by establishing a reverse bias across the junction set at a predetermined voltage value, measuring through a first probe a total junction current conduction value, measuring through second, third, and fourth probes a plurality of voltage values. The junction leakage value is then directly computed based on the sheet resistivity value, reverse bias potential, wafer radius, and the measured voltage values. Contact conductivity between a metal film and semiconductor layer can be similarly directly computed.

Abstract: A method and circuit to enable Four-Point Probe and Spreading Resistance techniques to overcome the high contact resistance in measuring the resistivities of III-V compound semiconductors. This is accomplished by using forward DC bias to greatly reduce the contact resistance of the potential probe to the III-V semiconductor while maintaining the AC input impedance of the potential probe to be several orders of magnitude higher than the DC input resistance, thus enabling use of the AC component to make potential measurements very accurately.

Abstract: A two-head probe apparatus measures sheet resistivities of the thin layer on a semiconductor wafer. On one side of the wafer, a first probe head makes contact for injecting current into the wafer and measuring the voltage difference between two surface points. On the other side of the wafer, a second probe head makes contact for monitoring the substrate potential at two probed points on the wafer substrate. The second probe is disposed below a platen supporting the wafer, and the probe electrodes are moved into spring biased contact with the wafer through apertures in the platen by a vacuum actuated piston. Circuitry coupled to the two probe heads computes leakage current and displays sheet resistivity.

Abstract: A cooking apparatus includes a vessel having a flue extending vertically therethrough. A gas heater is disposed beneath the flue. Food is boiled in water contained in the vessel. The bottom of the vessel is curved, and the flue is configured with a restriction in the lower portion thereof to provide even distribution of heat applied to the vessel.