SU823474A1 - Device for thermal treatment and liquid epitaxy of semiconductor materials - Google Patents

Description

This invention relates to process vacuum equipment for making crystals of electronic devices. A device for growing semiconductor crystals, made in the form of a cylindrical chamber with its direct heating C1, is known. However, due to uneven heating over the cylindrical body and the absence of heating elements from the ends, these devices are not suitable for growing a variety of thin-film multilayer monocrystalline semiconductor materials ... The closest to the proposed technical essence and the achieved result is a device for heat treatment and liquid epitaxy of semiconductor materials made of two cylindrical heat pipes, the surfaces of which form a working chamber for accommodating the material being processed. There are no cassette heating elements from the ends, the design is made integral 2J. The disadvantages of this device are the large inertia, unevenness, distribution of the temperature gradient along the axis, which leads to the beneficial use of only a small part of the heated volume from the entire furnace, inconvenience of maintenance, time consuming for preparatory and final operations, loading and unloading, low productivity and poor quality material cultivation. The purpose of the invention is to increase the effective volume of the chamber and ease of maintenance during loading and unloading. This goal is achieved by the fact that in a device for heat treatment and liquid epitaxy of semiconductor materials, including a working chamber for accommodating the material being processed, equipped with an ASh heater in the form of two heat pipes coaxially installed, the surfaces of which form a working chamber, one heat pipe is U-shaped and equipped with an axial mechanism. displacement, and the second pipe is made of an annular shape with a horizontal step and is installed inside the cavity of the first pipe. In addition, each pipe

equipped with an additional heater and the annular tube in the center has shafts connected to rotational drives.

FIG. 1 shows the proposed device, a general view; in fig. 2 scan of the working chamber, section; on fi-g. 3 shows section A-A in FIG. 2; in fig. 4 is a cross-section of the device along the axis B.

The device comprises a heat pipe 1 of annular shape, with an axial cylindrical hole and a ledge 2 along the end, a heat pipe 3 having a Shaped shape and forming with the heat pipe 1 a working chamber 4; a heater 5 located at the adjacent ends of both pipes; additional heater b; a heat insulating device 7 of the heat pipe 3; heat insulating device 8 heat pipe 1; internal shaft, 9 with 10 drive; tubular outer shaft 11 with a drive 12; a base 13 with water cooling channels 14, gas exhaust channels 15 and purge 16; thermostatic slots 17 and 18; lifting mechanism 19; power cables 20; technological cassette, including the base 21, with substrates 22, the movable part 23 with the socket epitaxial solutions 24, the cover 25; leash 26.

Heat pipes 1 and 3 are made airtight and filled with a liquid carrier such as sodium. In the closed state of chamber 4, the lower flanges of heat pipes 1 and 3 have thermal contact with heater 5. Under the action of heat of heater 5, the liquid in heat pipes 1 and 3 evaporates. The steam rises up and condenses on the internal surfaces of the walls, heating them to a predetermined temperature, and then the condensate flows downwards, where it evaporates again. Additional A heated heater heats the upper wall of the heat pipe 3 to a temperature close to that set for the working chamber 4. This provides an increase in speed and increased stability of the heating of the upper and outer walls of the working chamber 4. Heat from the walls of the working chamber .4 is transferred to a multi-socket cassette the shape of the chamber and fixed. base on the ledge 2 of the heat pipe 1.

Jumpers moving parts cas-. The sets are equipped with drivers 26 with nasal sockets for connection with drive shafts 9 and 11 and are located in a thermostating slot 18. Drives 10 and 12 rotate drive shafts 9, 11 and together with them moving parts of the cassette. Thus, alternate transfer is made to the sockets of the base of the cassette of epitaxial Hc1 solutions in the moving parts of the cassette. After filling the cassette sockets, the epitaxy of the next layer of a semi-semiconductor single-crystal structure is carried out. Heat pipe 3 with a heater 6 is protected by a thermal insulating device 7, hermetically connected to its flange. Heat pipe 1 with a heater 5. Protected by a heat insulating device 8, hermetically connected to its flange. Along the perimeter of the connection of the flanges of heat pipes 1 and 3, a thermostatic gap 17 is formed, in which the flow gas supplied through the purge channel 16 is preheated. From the working chamber 4 the gas is pumped out through the thermostatic gap 18 and the gas exhaust channel 15, Forcing the chamber cooling time It is carried out with cold running water flowing through the channels 14 of the base 13. Electric power is supplied to the auxiliary heater b through the cable 20. The same cable is connected to the heater 5 from the bottom.

The device works as follows.

The lifting mechanism 19 lifts the heat pipe 3 with an additional height of 6 cm with an additional heater 6 and a thermal insulation device 7. A technological cassette (Fig. 2-4) with crystallized. In the previous cycle of operation, semiconductor materials on the substrate 22 are removed from the ledge 2. of the heat pipe 1, and in place of the loading mechanism they install another cassette with the substrates 22 and solutions in the sockets 24 prepared for growing semiconductor materials. After that, the mechanism 19 lowers the heat pipe 3 with the heater 6 and the thermal insulation device 7 to the lowest position and presses its flange to the base 13 to seal the working chamber 4. After that, the working chamber is pumped out, blown with an inert gas and heated to the specified temperature. For growing Ga As, for example, the chamber needs to be heated to. Then the solutions begin to cool at a certain predetermined rate,

The resulting supersaturation in solution ensures the crystallization of a layer of a given composition on the substrate 22. Through drives 10 and 12, the drive rolls 9 and 11 are rotated together with them moving parts of the cassette containing slots with openings. In this way, the substrate 22 is alternately contacted with the solution contained in the sockets 24 and the semiconductor layers of the desired composition are expanded. The kiln cycle is repeated.

. Heating of the cassette from the ends, from the inner wall of the outer heat pipe and the outer wall of the inner heat pipe provides high stability of the temperature gradient (T 4 axial () and radial (h - h) directions and throughout the entire working chamber of the device. The working chamber is made detachable and minimum allowable, the volume defined by the size h - h, accelerates loading, exhaust air and unloading. Thermostatic slots 17 and 18 exclude the possibility of penetration of gases having a temperature different from Ions of the internal work chamber, during the purging of the working chamber with an inert gas. Identical controlled thermal heating of the ring cassette from all sides improves the specified distribution of the temperature gradient inside the process cassette in all directions by 2-3 times, which allows to grow multilayer film-film semiconductor structures. tours of a number of new materials and will increase by 2-3 times the quality (yield of) expensive materials used at present in various quantum electronic devices. The connector of the working chamber and the reduction of its volume to the level required is useful several times to reduce the time of installation and removal of cassettes, pumping out gases and purging the chamber with inert gases. Conditions for automatic loading and unloading} and camera

Claims (2)

-E create so simplest manipula torus. The productivity of the device is increased 1.5-2 times. Claim 1. Device for heat treatment and liquid epitaxy. Semi-direct materials, including a working chamber for accommodating the material being treated, equipped with heaters in the form of coaxially installed two heat pipes, the surfaces of which form a working chamber, characterized in that, in order to increase the useful the volume of the chamber and the convenience of servicing during loading and unloading, one heat pipe is made of a P-shaped form and is equipped with a axial movement mechanism, and the second pipe is made of an annular Forms with a horizontal ledge and installed inside the cavity of the first pipe. 2. The device according to claim 1, is different. in that each pipe is provided with an additional heater, and the annular pipe in the center has shafts connected to rotational drives. Sources of information taken into account in the examination of li Japanese Patent No. 52-914, B 01 j 17/20, NCI 13 (7) D 522, cl. 01.11.77. 3857990, 2. US patent; cl. H 05 B 3/66, NCI 13-22, - 06/27/73 (prototype). L Fng.2