Seiko Epson Corporation

Seiki Epson Corporation

Tetsuya Seki

Hideaki Iwano

Takashi Takeda

Masatoshi Yonekubo

Osamu Yokoyama

Hidefumi Sakata

Tatsuya Asaka

Shigeru Kogure

Takashi Takamura

A small and inexpensive optical head for detecting a recorded signal, a focusing error signal and a tracking error signal, and an optical memory device utilizing the optical head. A diffraction device (103) is provided having two chirped grating regions (103A, 103B) for dividing a light beam from an optical recording medium (105) and directing the divided beams toward four band-shaped photoelectric transducers (106) and an astigmatism generator formed by the diffraction device (103) and a positive lens (102). The four photoelectric transducers are positioned in a plane inclined with respect to the optical axis of zero-order diffraction light, and the longitudinal axes of each of the band-shaped photoelectric transducers are radially arranged relative to the optical axis.

Optical head and optical memory device

A microwave ECR plasma etching method and apparatus employs a combination reactive gas medium supplied to a microwave excitation ECR plasma chamber coupled to a treatment chamber containing a Group II-VI sample to be etched. A reactive gas plasma is formed containing reactive species in the plasma chamber and the Group II-VI sample is irradiated with a beam of reactive species formed from the reactive gas plasma. The reactive gas medium is selected from the group consisting of a hydrogen halogenate, a mixture of a halogen gas and an inert gas, a mixture of a halogen gas and hydrogen gas, a mixture of a halogen gas, an inert gas and hydrogen gas, and a mixture of a halogen gas and nitrogen gas.

Method of anisotropic dry etching of thin film semiconductors

A microwave ECR plasma etching method and apparatus, including a plasma generating chamber coupled to a separate treatment chamber for supporting a Group II-VI sample to be dry etched, are tailored for the dry etching of Group II-VI compound semiconductors resulting in highly anisotropic etched patterns in Group II-VI materials having vertical side walls taking advantage of the ionicity of the constituents of Group II-VI compounds and utilizing a low ion energy level which will not damage the crystalline integrity of the Group II-VI material. The apparatus may further include counter bias means and/or transverse magnetic field means in a region between the plasma generating chamber and the treatment chamber to improve the reactionary quality of the species and lower the energy level of the species without losing control and directionality of the species flow into the treatment chamber thereby preventing damage to the crystalline structure of the etched II-VI sample.

Growing community of inventors

Suwa, Japan

Tetsuya Seki