Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Materials Corporation

Mitsubishi Materials Silicon Corporation

Tetsuya Nakai

Yasuo Yamaguchi

Tadashi Nishimura

Hiroshi Shinyashiki

Takao Fujikawa

Jun Furukawa

Takuya Masui

Mitsuru Sudou

A hot isostatic pressing treatment is conducted for a single crystal body ( ) in an atmosphere where the single crystal body ( ) is stable, under a pressure of 0.2 to 304 MPa at a temperature which is 0.85 or more times the melting point in an absolute temperature unit of the single crystal body ( ), for 5 minutes to 20 hours; and the single crystal body ( ) is annealed. It is preferable that the atmosphere where the single crystal body ( ) is stable is an inert gas atmosphere or an atmosphere containing vapor of a high vapor pressure element, and it is more preferable that the HIP treatment is conducted under a pressure of 10 to 200 MPa. Further, the single crystal body ( ) may be an ingot of a silicon single crystal, a GaAs single crystal, an InP single crystal, a ZnS single crystal or a ZnSe single crystal, or a block or wafer obtained by slicing the ingot. In this way, there are expelled or dispersed those lattice defects such as vacancy type grown-in defects existing not only at the surface but also at the interior of the single crystal body ( ), irrespectively of the size of the single crystal body ( ).

Method of removing defects of single crystal material and single crystal material from which defects are removed by the method

Oxygen ion is implanted into a silicon substrate to remain a silicon layer on a surface of the silicon substrate. In this state, a silicon oxide layer is formed under the silicon layer. Silicon oxide particles are formed and remained in the residual silicon layer. While maintaining this state, the silicon substrate is heated to a predetermined temperature not less than 1300.degree. C. Alternatively, the silicon substrate is heated at a high temperature-rise rate to 900-1100.degree. C., and thereafter is heated at a low temperature-rise rate to the temperature not less than 1300.degree. C. The silicon substrate is held at the predetermined temperature not less than 1300.degree. C. for a predetermined time, whereby crystallinity of the residual silicon layer is restored. A pinning effect of the silicon oxide particles prevents the rise of dislocation to the surface of the SOI layer, and also suppresses a rate per a unit time at which interstitial silicon generates during the heating to the high temperature region. Therefore, a dislocation density of the SOI layer can be reduced.

SOI substrate having monocrystal silicon layer on insulating film

Oxygen ion is implanted into a silicon substrate to remain a silicon layer on a surface of the silicon substrate. In this state, a silicon oxide layer is formed under the silicon layer. Silicon oxide particles are formed and remained in the residual silicon layer. While maintaining this state, the silicon substrate is heated to a predetermined temperature not less than 1300.degree. C. Alternatively, the silicon substrate is heated at a high temperature-rise rate to 900.degree.-1100.degree. C., and thereafter is heated at a low temperature-rise rate to the temperature not less than 1300.degree. C. The silicon substrate is held at the predetermined temperature not less than 1300.degree. C. for a predetermined time, whereby crystallinity of the residual silicon layer is restored. A pinning effect of the silicon oxide particles prevents the rise of dislocation to the surface of the SOI layer, and also suppresses a rate per a unit time at which interstitial silicon generates during the heating to the high temperature region. Therefore, a dislocation density of the SOI layer can be reduced.

Method of manufacturing a SOI substrate having a monocrystalline silicon

A polysilicon layer is formed on a surface of a silicon substrate after oxygen ions are implanted into the silicon substrate and an SiO.sub.2 film is formed in the silicon substrate at a position in a prescribed depth from the surface of silicon substrate. A heat treatment is performed to a silicon layer between the polysilicon layer and the SiO.sub.2 film, thereby providing an SOI layer with improved crystal quality.

Method of manufacturing substrate having semiconductor on insulator

A polysilicon or amorphous Si layer is formed on a surface of a silicon substrate. Oxygen ions are implanted into the silicon substrate through the polysilicon layer, and an SiO.sub.2 film is formed in the silicon substrate at a position in a prescribed depth from the surface of silicon substrate. A heat treatment is performed to a silicon layer between the polysilicon layer and the SiO.sub.2 film, thereby providing an SOI layer with improved crystal quality.

Growing community of inventors

Saitama-ken, Japan

Tetsuya Nakai