| 摘要 |
PURPOSE:To enable to detect the low resistance part of a semi-insulating semiconductor single crystal substrate, and to facilitate the decision of quality when quality of the semi-insulating semiconductor single crystal substrate is to be decided by a method wherein a slender mask to screen a part of light is transferred irradiating the whole surface of the substrate with light, and a resistance value between electrodes equipped to both the sides of the substrate is measured. CONSTITUTION:When the insulating characteristic of a semi-insulating single crystal substrate 11 such as Si, GaAs,, InP, etc. is to be investigated, electrodes 12 consisting of In, etc. are equipped to the opposite edge parts of the substrate 11 at first, and the series circuit of an AC power source and an ammeter 17 is connected between the electrodes thereof. Then the surface of the substrate 11 is irradiated uniformly from the direction shown with arrow marks 15 with light 15 radiated from a tungsten lamp, and at the same time, a mask 13 of about 2.5mm. width is transferred intersecting the light 15, and the shadow 16 thereof is formed on the surface of the substrate 11. Accordingly, photoelectrons are generated at the part shone with the light 15 to reduce the resistance value at this place to about 1/100 of the resistance value of the shadow 16 part. Namely, the whole surface of the substrate 11 is scanned, and inequality of the substrate resistance value is judged. |
