Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Masaburo Iwabuchi

Kenji Unetsubo

Hideyoshi Ito

Kiyoshi Hisatomi

A dopant film contains an organic binder, an inorganic binder and a compound of an impurity element for diffusion. Both surfaces of the dopant film are coated with adhesive. Releasable sheets sandwich the dopant film. The dopant film permits automated alternate stacking with semiconductor wafers, providing an advantage of labor saving. When the alternate stacking is automated, it will become hard for the wafer breakage to occur, sharply decreasing the rate of breakage. Furthermore, since the adhesion of a semiconductor wafer improves, the variation in the diffusion depth will decrease.

Dopant film and methods of diffusing impurity into and manufacturing a

A dopant film contains an organic binder, an inorganic binder and a compound of an impurity element for diffusion. Both surfaces of the dopant film are coated with adhesive. Releasable sheets sandwich the dopant film. The dopant film permits automated alternate stacking with semiconductor wafers, providing an advantage of labor saving. When the alternate stacking is automated, it will become hard for the wafer breakage to occur, sharply decreasing the rate of breakage. Furthermore, since the adhesion of a semiconductor wafer improves, the variation in the diffusion depth will decrease. The semiconductor wafer manufacturing method includes the steps of impurity diffusion into both surfaces, dividing the wafer into two wafers in the direction of thickness, and polishing to a mirror surface each divided wafer opposite to the surface on which the impurity diffusion layer is formed. The material loss per wafer is reduced more than the conventional method due to the slicing into two wafers.

The edge part of a thin disc-shaped slice, i.e., wafer, transversely cut off a single-crystal semiconductor rod is bevel machine, and then the entire surface of this wafer is mirror finished. This mirror finish is obtained by carrying out chemical etching to the ordinary depth and then carryng out polishing by means of a polishing fabric. By this process, all surfaces of the semiconductor wafer are polished to a mirror finish, and the formation of dendrite crystals on any of the surfaces is inhibited.

Semiconductor wafer process

In a lapping apparatus, washing water is ejected from washing water holes toward a carrier holding wafers after the wafers are polished. Thus, the wafers are separated from the carrier and upper and lower polishing members. Then, the carrier is forced up above the upper polishing member by a pushing ring. The wafers left on the upper member are carried onto a table by a first sweeper of an automatic collecting device. The transferred wafers are arranged in a line along a second sweeper. Then, the second sweeper pushes and moves the wafers in the direction of their arrangement toward a cassette on one side of the table. The wafers are housed in holder portions in the cassette, and are then immersed, along with the cassette, in a pure water tank.

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Yokohama, Japan

Masaburo Iwabuchi