Sony Corporation

Sony Corporation Research Center

Akashi Sawada

Setsuo Usui

Akikazu Shibata

Yoshinori Hayafuji

Yoshinari Hayafuji

Seed crystals are made in a region of a polycrystalline layer on a substrate using a beam of electrons. The beam is used to melt the region, which is then solidified from one end to the other in a first direction and outwardly toward the edges in a second direction normal to the first direction. Several different techniques can be used to promote solidification in the proper directions. The region can be heated non-uniformly and then cooled to maintain the desired temperature distribution. The region can also be cooled non-uniformly to provide the desired temperature distribution. The region can be heated non-uniformly using apparatus that controls the energy deposited in the region by the electron beam.

Method for making seed crystals for single-crystal semiconductor devices

A large, single-crystal semiconductor device is made from a substrate having a layer of polycrystalline or amorphous material thereon by exposing a region of the layer to a beam of electrons to melt the region and then solidifying the molten region from one end to the other in a first direction and outwardly toward the edges in a second direction normal to the first direction to form a single-crystal seed in the region. An operating layer of polycrystalline or amorphous material on the substrate in contact with the seed is scanned with a beam of electrons having a strip-like configuration. The beam remelts a portion of the seed and creates a molten zone in the layer that recrystallizes as a single crystal by lateral epitaxial recrystallization from the seed.

Single-crystal semiconductor devices and method for making them

Seed crystals are made in a region of a polycrystalline layer on a substrate by melting the region and then cooling it so that it solidifies from one end to the other in a first direction and outwardly toward the edges in a second direction normal to the first direction. The desired cooling pattern is established by providing a thermal layer under the polycrystalline layer, which thermal layer is used to provide different rates of heat conduction therethrough in different parts of the thermal layer. A large, single-crystal device can be made by providing an operating layer of polycrystalline material in contact with the seed, melting the operating layer and recrystallizing it so that its solidification proceeds from the seed. The thermal layer can be used to ensure the desired direction of resolidification by providing different rates of heat conduction therethrough in different parts of the thermal layer.

Growing community of inventors

Yokohama, Japan

Akashi Sawada