Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Masakatu Kojima

Youji Yamashita

Shuichi Samata

Norihiko Tsuchiya

Masanori Numano

Atsuko Kubota

Yoshihiro Ueno

Yoshiaki Matsushita

Masanobu Ogino

Provided is a process for producing a semiconductor silicon wafer by which an intrinsic gettering effect can be improved and at the same time the top side can be made free from faults. A silicon ingot is produced and sliced to obtain silicon wafers. Then, a polycrystal silicon depositing film is formed on one side of a silicon wafer, which is subjected to a heat treatment in an inert gas, a reducing gas or a mixture thereof to discharge oxygen from the vicinity of the other side. Alternatively, after discharging oxygen from the silicon wafer by a heat treatment, a polycrystal silicon depositing film may be formed on one side of the silicon wafer.

Semiconductor silicon wafer and process for producing it

Process for producing Semiconductor silicon wafer

A crystal pulling method includes the steps of disposing a separation wall concentrically with an in a semiconductor crystal pulling crucible to divide the crucible into an inner chamber and an outer chamber, putting first doped material melt into the inner chamber and second material melt into the outer chamber, and pulling crystal from the first material melt in the inner chamber while the second material melt in the outer chamber is being supplied to the inner chamber via a coupling member which connects the inner and outer chamber with each other but suppresses the outflow of impurity from the inner chamber to the outer chamber. Assume that k is the segregation coefficient of doping impurity in the first material melt, r is half the inner diameter of the inner chamber, and R is half the inner diameter of the outer chamber. The second material melt in the outer chamber is undoped melt, and the condition of (r/R)&gt;.sqroot.k is set to increase the doping impurity concentration in the longitudinal direction of the crystal, or the condition of (r/R)&lt;.sqroot.k is set to lower the doping impurity concentration in the longitudinal direction of the crystal so as to compensate for or cancel the influence by conductive impurity which has flowed out of the crucible and mixed into the melt, thus controlling the resistivity of the pulling crystal in the longitudinal direction thereof.

Semiconductor crystal pulling method

A crystal pulling apparatus of double structure crucible has a crucible body which is divided into inner and outer chambers by a cylindrical partition wall coaxially disposed in the crucible body. A melt supplying path used to supply melt from the outer chamber of the crucible to the inner chamber in which the crystal is pulled is formed of a small through hole formed in the partition wall or the small through hole and a pipe-like passage formed in communication with small through hole. The radius of the inner chamber of the double structure crucible has a specified relation determined by the segregation coefficient of dopant impurity with respect to the radius of the outer chamber. This is, the radius of the inner chamber is set substantially equal to .sqroot.k times the radius of the outer chamber when the segregation coefficient of the dopant impurity is k. In the crystal pulling apparatus with the double structure crucible, a small chamber for introducing dopant is disposed in the outer chamber of the crucible to be in communication with the inner chamber.

Crystal pulling apparatus and crystal pulling method

In a crystal pulling process using an integral type double crucible, a cylindrical separation wall is mounted in and is coaxial with a crucible, for receiving semiconductor material melt to divide the crucible into inner and outer chambers. A coupling tube fixed at the side wall of the separation wall and having a pipe-like passage with a small hole is provided to make a pass between the inner and outer chambers. While material melt in the outer chamber is being supplied to the inner chamber via the coupling tube, crystal is pulled from the melt received in the inner chamber and having an impurity composition different from that of the melt in the outer chamber.

Crystal pulling apparatus and crystal pulling method using the same

The present invention discloses a crystal pulling apparatus having a double-crucible structure, wherein an inner crucible is located in an outer crucible. An end of a pipe-like passage is located in a through hole formed in a side wall of an inner crucible located in an outer crucible, and a melt is supplied from the outer crucible to the inner crucible through the pipe-like passage, during crystal pulling. During melting or neckdown, prior to crystal pulling, diffusion of an impurity between the melts in the outer crucible and the inner crucible, and exchange of the melts between the outer crucible and the inner crucible are prevented by the pipe-like passage.

Crystal pulling apparatus

An apparatus for growing compound semiconductor single crystals includes a collector which removes the excess amount of melt B.sub.2 O.sub.3 from the crucible containing melt GaP and melt B.sub.2 O.sub.3. The collector moves up and down independently with reference to the shaft used in pulling the single crystals from the crucible.

Apparatus for growing compound semiconductor single crystals

An apparatus for producing monocrystalline silicon uniformly containing oxygen at a high concentration. The invention provides an apparatus that employs an improvement in the Czochralski method for producing monocrystalline silicon. The apparatus includes an annular shaped member which floats on the surface of the silicon melt and prevents the escape of oxygen from the silicon melt. The member rotates around a pull of monocrystalline silicon which is pulled through the aperture of the member. The member preferably is made of quartz which supplies oxygen to the silicon melt and thereby increases the concentration of oxygen in the melt.

Growing community of inventors

Yokosuka, Japan

Masakatu Kojima