SEMICONDUCTOR DEVICE

• Main Author: YAMAZAKI SHUNPEI
• Format: Patent
• Language: English; Japanese
• Published: 27.07.2020
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

To provide a transistor with favorable electrical characteristics, in a transistor including an oxide semiconductor, and a manufacturing method of the transistor.SOLUTION: A first oxide insulating film is formed over a substrate. After a first oxide semiconductor film is formed over the first oxide insulating film, heat treatment is performed, so that hydrogen contained in the first oxide semiconductor film is released and part of oxygen contained in the first oxide insulating film is diffused into the first oxide semiconductor film. Thus, a second oxide semiconductor film with reduced hydrogen concentration and reduced oxygen defect is formed. Then, the second oxide semiconductor film is selectively etched to form a third oxide semiconductor film, and a second oxide insulating film is formed. The second oxide insulating film is selectively etched to form a protective film covering an end portion of the third oxide semiconductor film. Then, a pair of electrodes, a gate insulating film, and a gate electrode are formed over the third oxide semiconductor film and the protective film.SELECTED DRAWING: Figure 1 【課題】酸化物半導体を用いるトランジスタにおいて、電気特性の良好なトランジスタ及びその作製方法を提供する。【解決手段】基板上に第１の酸化絶縁膜を形成し、該第１の酸化絶縁膜上に第１の酸化物半導体膜を形成した後、加熱処理を行い、第１の酸化物半導体膜に含まれる水素を脱離させつつ、第１の酸化絶縁膜に含まれる酸素の一部を第１の酸化物半導体膜に拡散させ、水素濃度及び酸素欠陥を低減させた第２の酸化物半導体膜を形成する。次に、第２の酸化物半導体膜を選択的にエッチングして、第３の酸化物半導体膜を形成した後、第２の酸化絶縁膜を形成して、当該第２の酸化絶縁膜を選択的にエッチングして、第３の酸化物半導体膜の端部を覆う保護膜を形成する。この後、第３の酸化物半導体膜及び保護膜上に一対の電極、ゲート絶縁膜、及びゲート電極を形成する。【選択図】図１