SU910837A1 - Apparatus for thermal evaporation of materials in vacuum - Google Patents

Description

(54) DEVICE FOR THERMAL EVAPORATION OF MATERIALS IN VACUUM

I

The invention relates to vacuum technology, in particular to vacuum coaters.

A device for thermal evaporation of materials in vacuum is known, which comprises a rod made of evaporating material and serving as a cathode, and an anode. When an electron beam is bombarded by a rod, it is heated and a drop of molten material l forms at its end.

The disadvantage of this device is that when heated, the rod itself creates a darkening for the vapors of the evaporated material, as a result of which the coating on the inner surface of the bodies is not uniformly vrashenn.

The closest to the invention to the technical essence and the achieved result is a device for thermal evaporation of materials in vacuum, containing a crucible with a resistive heater, in which the evaporated material 12 is placed.

However, the known device does not allow uniform coating of the inner surface of the bodies of rotation due to non-uniform radiation heating of the substrate.

The purpose of the invention is to increase the uniformity of the coating on the inner surface of the bodies. rotation

ten

This goal is achieved by the fact that a device for thermal evaporation of materials in vacuum, containing a crucible for accommodating evaporated material and a heater, is equipped with a pipeline

Claims (2)

15 for pumping and gas inlet, while the crucible is made in the form of a sealed hollow sphere of. refractory material and is connected to the pipeline for pumping and gas inlet, and the heater is filled as a pair of electrodes to initiate a glow discharge consisting of a cathode, which is the sphere itself of refractory material, and an igar-like anode fixed in pentre cx | and isolated from it. The drawing shows a schematic depiction of a device for thermal evaporation of materials ъ vacuum The device contains a spherical cathode 1 rigidly connected with a current lead 2, an insulator 3, a pipe 4, an anode 5 spheres the valve 6 with openings 7. Evaporated material (not shown) will interfere into the interelectrode space. The device operates as follows. The interelectrode space is vacuum through conduit 4 and then filled with the gas needed to ignite the glow discharge. The cathode supplies a voltage that supplies a glowing discharge between them. This causes the cathode and the psjry material to heat up. The specific cathode power is set such that the evaporated material is completely transformed into a vapor on the set. The evaporating material is transferred by structural defects (dislocation), resulting from the bombardment of the inner surface of the cathode to glow discharge ions, as a result of which the evaporated material enters the outer surface of the cathode and evaporates. The evaporation rate of the material at the selected temperature is equal to the rate of diffusion penetration through the cathode wall. The cathode wall thickness is chosen from the condition that the temperature on its outer surface is not much less than that on its inner surface, and the concentration of the coating material on the outer surface should provide the necessary evaporation rate. An anode and a molybdum cathode were installed as the applied material. Copper is used, the cathode wall thickness is 0.7 mm, which at a cathode temperature provides a copper surface concentration of 0.05% and, accordingly, the evaporation rate in vacuum is 1 g / cm. The evaporation rate of the cathode-molybdenum material itself at 1650 ° C is 10 T / cm s. Thus, this device provides uniform coating on the inner surface of rotation. The invention. A device for thermal evaporation of materials in vacuum, containing a crucible for accommodating an evaporated material and a heater, is designed so that, in order to increase the uniformity of coating on the internal surface of the bodies of revolution, the device is equipped with a pipeline dp of pumping and gas in The crucible is made in the form of a sealed hollow sphere of a refractory material and is connected to a pipeline for pumping out and gas inlet, and the heater is made in the form of a pair of electrodes for initiating a glow discharge, PICs consisting of a cathode, which is itself the scope of RS refractory, spherical anode and fastened in the center of the sphere and insulated from it. Sources of information taken into account in the examination 1. Technology of thin films. Ed. L. Mysella and R. Glang, Trans. from English M., Soviet Radio, 1976, Vol. 1., p. 72. 2. Danilin B.S. Vacuum technology in the manufacture of integrated circuits. M., Energie, 1972, p. 54-55, 149-15 (prototype).