Abstract: A wide-gap semiconductor substrate enables formation of a device having low power loss while maintaining high mechanical strength. The wide-gap semiconductor substrate (70) is obtained by placing a wide-gap semiconductor substrate onto a platen (15) disposed in a processing chamber (11) and etching and thinning only a first substrate region (70a), where a device (50) is formed, of the wide-gap semiconductor substrate by means of plasma generated from an etching gas. In the wide-gap semiconductor substrate (70), a connecting portion as a peripheral edge of the first substrate region (70a) connecting to a second substrate region (70b) surrounding the first substrate region (70a) includes an arc portion having a predetermined radius of curvature.

Abstract: A plasma etching method forms a tapered recess portion in a wide-gap semiconductor substrate. The method includes forming on the substrate K an etching film having an etching speed higher than that of the substrate K, and forming a mask M having an opening on the high-speed etching film. The substrate K with the etching film and the mask is then placed on a platen and heated to a temperature equal to or higher than 200 ° C., a plasma is generated from an etching gas supplied into a processing chamber, and a bias potential is applied to the platen to etch substrate.

Abstract: An object of the present invention is to provide a plasma etching method capable of forming a tapered recess portion in a wide-gap semiconductor substrate. As a solving means therefor, a high speed etching film E an etching speed of which is higher than that of a wide-gap semiconductor substrate K is formed on the wide-gap semiconductor substrate K, and a mask M having an opening is formed on the high speed etching film E. Thereafter, the wide-gap semiconductor substrate K having the high speed etching film E and the mask M formed thereon is placed on a platen and is heated to a temperature equal to or higher than 200° C., then a plasma is generated form an etching gas supplied into a processing chamber and a bias potential is applied to the platen, and thereby the wide-gap semiconductor substrate K is etched.

Abstract: A plasma etching method capable of forming a tapering etching structure having a smooth surface is provided. A fluorine-containing gas and a nitrogen gas are used and plasma is generated from these gases simultaneously, and a silicon substrate K is etched by the plasma while an etch-resistant layer is formed on the silicon substrate K by the plasma and then a fluorine-containing gas and an oxygen-containing gas are used and plasma is generated from these gases simultaneously, and the silicon substrate K is etched by the plasma while an etch-resistant layer is formed on the silicon substrate K by the plasma generated from the oxygen-containing gas, thereby forming a tapering etching structure H having a wide top opening width and a narrow bottom width.

Abstract: A plasma etching method capable of forming a tapering etching structure having a smooth surface is provided. A fluorine-containing gas and a nitrogen gas are used and plasma is generated from these gases simultaneously, and a silicon substrate K is etched by the plasma while an etch-resistant layer is formed on the silicon substrate K by the plasma and then a fluorine-containing gas and an oxygen-containing gas are used and plasma is generated from these gases simultaneously, and the silicon substrate K is etched by the plasma while an etch-resistant layer is formed on the silicon substrate K by the plasma generated from the oxygen-containing gas, thereby forming a tapering etching structure H having a wide top opening width and a narrow bottom width.

Abstract: The present invention relates to a plasma etching apparatus capable of uniformly etching the entire surface of a substrate regardless of the kind of the substrate.

Abstract: A plasma generator for generating a plasma exhibiting a uniform etching rate in a circumferential direction of a sample and a plasma etching device enabling a uniform etching in a circumferential direction of a sample are provided. To generate a plasma of a process gas, the process gas is introduced into a plasma generating chamber while a predetermined pressure is kept, and a high-frequency alternating voltage is applied to a coil. By applying an alternating voltage is applied to a substrate electrode, the plasma generated in the plasma generating chamber is brought into a reaction chamber and a sample is etched. The coil is not wound in a uniform helical shape. One turn of the coil has a first winding portion wound horizontally or generally horizontally and a second winding portion wound at a sharply inclined angle.