Atsuya Akiba has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
Abstract: In a method of manufacturing a silicon carbide semiconductor device, a trench and a thickness measurement section are formed in a surface of a semiconductor substrate made of silicon carbide. The thickness measurement section includes a plurality of grooves and a protruding portion provided between the grooves so as to have a predetermined width. When an epitaxial layer made of silicon carbide is grown, a thickness of the epitaxial layer formed on the surface of the semiconductor substrate is measured by calculating a difference in height between a surface of the epitaxial layer formed on a portion of the surface of the semiconductor substrate different from the thickness measurement section and a top surface of the protruding portion. The predetermined width is less than a surface migration amount of atoms during growth of the epitaxial layer.
Abstract: In a method of making a silicon carbide semiconductor device having a MOSFET, after a mask is placed on a surface of a first conductivity type drift layer of silicon carbide, ion implantation is performed by using the mask to form a lower layer of a deep layer extending in one direction. A first conductivity type current scattering layer having a higher concentration than the drift layer is formed on the surface of the drift layer. After another mask is placed on a surface of the current scattering layer, ion implantation is performed by using the other mask to form an upper layer of the deep layer at a position corresponding to the lower layer in such a manner that the lower layer and the upper layer are connected together.