Abstract: A field effect transistor including a gate insulation portion, an organic semiconductor portion, a source electrode and a drain electrode, wherein when a voltage is applied to the gate at 70° C. for 5.0±0.1 hours so that the field strength in the gate insulation portion would be 100±5 MV/m, the change in the threshold voltage is within 5 V. The organic semiconductor portion has a high driving stability, of which the change in characteristics by driving is thereby small.

Abstract: A field effect transistor including a gate isulation portion, an organic semiconductor portion, a source electrode and a drain electrode, wherein when a voltage is applied to the gate at 70° C. for 5.0±0.1 hours so that the field strength in the gate insulation portion would be 100±5 MV/m, the change in the threshold voltage is within 5 V. The organic semiconductor portion has a high driving stability, of which the change in characteristics by driving is thereby small.

Abstract: The disclosure describes a magnetic recording medium having at least a magnetic layer, optionally by means of an under layer, on a non-magnetic substrate, wherein projections formed by irradiation of an energy beam and each having a height from 1 to 60 nm are provided at the number of 102 to 108 per 1 mm2 on the surface of any one of the non-magnetic substrate, the under layer, the magnetic layer and the magnetic recording medium.

Abstract: The present invention relates to a method of inspecting a magnetic disc, comprising:optically inspecting a surface of said magnetic disc to detect defects thereon; andconducting a magnetic defect inspection to an area which is smaller than said optically inspected surface and including the optically detected defective portions and vicinities thereof.

Abstract: A texturing apparatus for applying a texturing to a magnetic recording medium, such as a magnetic disk including a hard drive. A substrate such as a magnetic disk is held by a substrate rotating system, which is capable of rotating the substrate. A movable laser beam source including an electro-optic modulation circuit directs a laser beam through a focusing element onto the surface of the substrate. The modulation circuit allows the laser beam to pulse at a frequency from 0.1 to 100 MHz. The focusing element allows a laser beam spot diameter of 0.2 to 4 .mu.m on the surface of the substrate. This texturing includes texturing the magnetic head contact start and stop (CSS) area of hard disks.

Abstract: The disclosure describes a magnetic recording medium having at least a magnetic layer, optionally by means of an under layer, on a non-magnetic substrate, wherein projections formed by irradiation of an energy beam and each having a height from 1 to 60 nm are provided at the number of 10.sup.2 to 10.sup.8 per 1 mm.sup.2 on the surface of any one of the non-magnetic substrate, the under layer, the magnetic layer and the magnetic recording medium.