Semitex Co., Ltd.

Toshiba Ceramics Co., Ltd.

School Judicial Person Ikutokugakuen

Tateo Kusama

Kunio Iba

Yoshio Kirino

Yoichiro Ogita

Kinio Iba

A method of and apparatus for evaluating the lifetime of a semiconductor material which is capable of measuring, in a non-contact and non-destructive manner, the lifetime of a surface thin-layer portion so as to evaluate the quality of a semiconductor device formed of an epitaxial wafer or a thin device-forming material. Light within a short-wavelength region is radiated for a short period of time on the surface of a semiconductor material to be evaluated, thereby generating carriers effectively on the surface and in a surface thin-layer. An electromagnetic wave within a millimeter to sub-millimeter wave region is projected onto the surface, and a wave reflected from the surface is measured to obtain a decay curve of the carriers. On the basis of the carrier decay curve, the lifetime of the surface as well as a surface thin-layer portion of the semiconductor material is evaluated.

Method of evaluating lifetime of semiconductor material and apparatus

A method and apparatus measure the lifetime of semiconductor materials having resistivity values within a predetermined measurement range. Carriers are produced within the semiconductor material responsive to incident energy. Microwave energy is radiated from a waveguide onto the semiconductor material to obtain reflected microwave energy. The equivalent distribution circuit characteristics of the waveguide are varied such that a variation of a magnitude of the reflective microwave energy relative to a resistivity of the semiconductor material is substantially linear within the predetemined measurement range. Plural stub tuners are provided within the waveguide to obtain the desired linear characteristics. The lifetime measurement is obtained in accordance with an attenuation of the produced carriers.

Method and apparatus for measuring lifetime of semiconductor material

A method and apparatus measure the lifetime of a semiconductor material by directing microwave energy into the semiconductor material and by producing carriers within the semiconductor material by impinging light thereon. A non-metal material is interposed between the semiconductor material and a metallic surface, such that a portion of the microwave energy travels through the semiconductor material and the non-metal material and reflects off of the metallic surface and back through the non-metal material and the semiconductor material. Additionally, a heating member is provided for heating the semiconductor material, whereby the lifetime of the semiconductor material is determined according to characteristics of the reflected microwave energy and the temperature of the semiconductor material.

Method for measuring lifetime of semiconductor material and apparatus

A semiconductor specimen is held by a stage which is equipped with a heater (and a cooler) to change the temperature of the specimen in a predetermined range. Minority carriers are generated in the specimen by irradiating it with an energy beam such as a laser beam. A signal reflecting the recombination process of minority carriers is detected in a non-contact manner by a combination of microwave oscillator and a microwave detector through the microwave impedance coupling with the specimen. Decay curves are obtained at a plurality of temperatures in the predetermined range. A deep impurity level in the specimen is determined by performing an Arrhenius' plot on the basis of the plurality of signal decay curves and the corresponding specimen temperatures.

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Tokyo, Japan

Tateo Kusama