Murata Manufacturing Co., Ltd.

Tomoyasu Miyata

Koichi Sakamoto

Yasuhiro Kuratani

Takao Mukai

Hideharu Yoshikawa

Masaaki Sueyoshi

Katsutoshi Toyama

A method of manufacturing an edge reflection type surface acoustic wave device using a Shear Horizontal type surface acoustic wave includes the steps of making a first half cut defining a first end surface portions having a smooth surface, that is, opposing two end surfaces which function as reflection end surfaces, from the upper surface of a piezoelectric substrate after at least one of a plurality of IDTs has been formed on the upper surface of the piezoelectric substrate, making a second half cut for forming second end surface portions having a rough surface after making the first cut, and making a full cut for cutting the piezoelectric substrate so as to reach the lower surface of the piezoelectric substrate outside of the second end surface portions in the surface acoustic wave propagation direction.

Method of manufacturing an edge reflection type surface acoustic wave device

A method of manufacturing an edge reflection type surface acoustic wave device using a Shear Horizontal type surface acoustic wave includes the steps of making a first half cut defining first end surface portions having a smooth surface, that is, opposing two end surfaces which function as reflection end surfaces, from the upper surface of a piezoelectric substrate after at least one of a plurality of IDTs has been formed on the upper surface of the piezoelectric substrate, making a second half cut for forming second end surface portions having a rough surface after making the first cut, and making a full cut for cutting the piezoelectric substrate so as to reach the lower surface of the piezoelectric substrate outside of the second end surface portions in the surface acoustic wave propagation direction.

Edge reflection type surface acoustic wave device and manufacturing method for the same

In a Schottky barrier diode, concentration of an electrical field at an edge of an insulation layer is suppressed to improve the reverse breakdown voltage. An n- layer of a compound semiconductor substrate having an n+ layer and the n- layer is configured in the form of a mesa. An insulation layer is formed on at least a skirt portion and a slant portion of the mesa. An anode is formed on the insulation layer and n- layer, and a cathode is formed on the n+ layer. Thus, concentration of an electrical field at an edge of the insulation layer is canceled at least in part by an electrical field generated at the anode on the slant portion to improve the reverse breakdown voltage.

Schottky barrier diode having a mesa structure

A Schottky barrier diode having improved breakdown characteristics has an n.sup.+ semiconductor layer and an n.sup.- semiconductor layer provided on the n.sup.+ semiconductor layer. The n.sup.- semiconductor layer is configured to form a mesa. An insulating layer is formed so as to expose the upper surface of the mesa. An anode electrode is provided on the exposed surface and a side surface of the mesa, while a cathode is electrically connected to the n.sup.+ layer. A plasma treated layer is provided in the n.sup.- semiconductor layer so as to extend inwardly from at least a portion of the side surface of the mesa.

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Kanazawa, Japan

Tomoyasu Miyata