JPS6365066A - Substrate temperature controller for vapor deposition device - Google Patents

Abstract

PURPOSE:To control the heating of a substrate to a required temp. with high accuracy by forming a heat pipe by a substrate holder and operating the same as an evaporating part for the heat transfer medium therein in the temp. control stage of the substrate for vapor deposition with a vapor deposition device. CONSTITUTION:The substrate 8 for vapor deposition is heated to the temp. optimum for vapor deposition by an IR lamp, etc., with the vacuum deposition device or sputtering vapor deposition device. The substrate holder 1 mounted with the substrate 8 is connected to a cylindrical shaft 2 which is formed of a good conductor of heat to a hollow shape and is sealed at the other end to form the heat pipe. A small amt. of the liquid which acts as the heat transfer medium is sealed under the reduced pressure into the hollow part and the shaft part 2 is mounted through a bell-jar 5 to a heat exchanger 7. the internal liquid is evaporated by the temp. of the heated substrate holder 1. The vapor is condensed to release the latent heat and is returned to the liquid in the heat exchanger part 7 and the liquid is thereby circulated. The temp. of the substrate holder 1; i.e., the substrate 8 is thus controlled by the temp. of the refrigerant of the heat exchanger 7 in the condensing part for the heat transfer medium, by which the temp. of the substrate 8 is controlled with the high accuracy of <=1 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a substrate temperature control device for a vapor deposition apparatus used for forming vapor deposited films on conductor elements and display panels.

(Prior Art) FIG. 3 shows a conventional vapor deposition apparatus'. A substrate 87 fixed to the substrate holder 1 inside the Pelger s is heated with an infrared lamp 9 provided inside the Pelger.

Since it is difficult to measure the temperature of the substrate directly, the substrate temperature was conventionally measured using a sheathed thermocouple that penetrated the Pelger positive wall near the base plate.

Therefore, the substrate temperature is controlled by feeding back the indicated value to the power control S of the infrared lamp to change the heating capacity of the lamp. That is, this control method is based on the premise that the indicated value of the thermocouple and the substrate temperature match, which is problematic.

(Problem to be solved by the invention) Two different objects are not necessarily the same even when exposed to the same heat source! Temperature is a secondary state quantity determined by the amount of heat energy entering and exiting a substance. Even if we assume a steady state and ignore temporal changes in the amount of stored energy, which varies greatly in terms of heat capacity, the amount of energy in and out will not be uniform depending on the surface condition and physical properties of the material. Since the inside of the Pelger is normally maintained at a high vacuum, heat is exchanged through radiation heat transfer. In this case, problems arise from the difference in infrared emissivity inherent to the materials and the difference between heat reception and heat radiation. Especially regarding the emissivity, it cannot be the same for the 7-space thermocouple because the deposited material is not specified. Furthermore, since the amount of radiant heat is proportional to the emissivity and is proportional to the fourth power of temperature, the higher the temperature, the more significant this difference becomes, and as a result, different objects have different temperatures.

(Means for Solving the Problems) In view of the above problems, the present inventor provides a method for directly controlling the temperature of a substrate holder that is in close contact with an object to be deposited, which is a child control object.

In a vacuum evaporation apparatus such as an electron beam bombardment method or a sputtering evaporation apparatus, the present invention has a substrate holder gold evaporation part that fixes the object to be deposited, and a shirt holder heat insulating part that fixes the holder to a Pelger. This is a substrate temperature control device in which a heat pipe is configured as a 9smt-condensing section of the shaft extending outside the Pelger, and a cooling heat exchanger is attached around the condensing section shaft.

The present invention will be explained using figures. In the first factor, the substrate holder 1 is a hollow body made of a good thermal conductor, and is connected to a cylindrical shaft whose other end is sealed to form a heat pipe. A small amount of liquid acting as a heat transfer medium is previously injected into this hollow interior under reduced pressure, and a wick 4 for promoting circulation of the liquid is inserted as necessary. The other end of the shaft 2 connected to the substrate holder 1 passes through the Pel jar 51 via a gasket 6, and a heat exchanger 7 for temperature control is attached to the part outside the Pel jar, that is, the condensing section.

(Function) The substrate 8, which is the object to be deposited, is heated by the infrared lamp 9, and in the sputtering apparatus, it is heated by thermal radiation from the facing high-temperature target and high-speed secondary electron beam irradiation. The incident energy of the substrate 8 is transmitted to the substrate holder 1 by thermal conduction. In the holder, which is also the evaporator of the heat pipe, the energy easily boils the sealed working fluid under reduced pressure. The working fluid, which has received and removed energy as latent heat, heads in a gaseous state to a low-temperature, low-pressure condensing section at a speed close to the speed of sound, where it is cooled and condensed by the action of a heat exchanger, releasing latent heat. The working fluid, which has returned to liquid form, travels through the inner wall of the heat pipe or wick due to gravity and surface tension, flows back to the base plate holder, which is the evaporation section, and undergoes one cycle of energy transfer. A feature of heat pipes is their high heat transfer coefficient, which is hundreds of times higher than that of copper. Due to the particularly high heat transfer coefficient, the temperature throughout the heat pipe is uniform. That is, the temperature of the substrate holder 1 can be controlled by the refrigerant temperature of the condenser heat exchanger. The temperature difference between the condensing section and the evaporating section can be easily set to 1° C. or less by the heat transfer characteristics of the heat pipe as well as the design of the heat exchanger and the quick.

Embodiment FIG. 2 shows one embodiment of the present invention. In order to make the thickness of the steam exchange uniform, in particular, a vacuum lid storage device which serves as a point source and a device 1 for rotating the base plate holder are installed. The shaft 2 constituting the heat pipe is also used as a rotating shaft, and the Pelger 5
It is connected to the rotary drive unit 10 at a sea part located outside of the rotary drive unit 10 . The working fluid is mostly water or freon at temperatures below 150°C, mercury or dowsum up to about 300°C, and metallic sodium or potassium at higher temperatures.

(Effects of the invention) According to the present invention, the number of substrates and board holders, the number of heat resistance tubes (
If the thermal design of the entire system is made appropriate, the substrate temperature can be controlled within ±1°C.

Due to the high thermal diffusivity, which is one of the features of heat pipes, even if the substrate temperature fluctuates due to some disturbance, it quickly returns to the set temperature.

Control of substrate temperature can be replaced with refrigerant temperature control of a heat exchanger, operation can be performed outside the Pelger, and the configuration of the °C system is easy.

That is, the present invention provides excellent thermal response.

It has become possible to realize a system that allows easy setting and stabilization of the substrate temperature regardless of whether it is steady or unsteady.

[Brief explanation of the drawing]

Fig. 1 is a front view illustrating the basic configuration of the invention, Fig. 2 shows an embodiment of the invention, and Fig. 3 is a schematic diagram of a conventional vapor deposition apparatus. It is a diagram. 1 Substrate holder 2 Shaft 3 Hydraulic fluid 4 Wick 5 Pelger 6 Gasket 7 Heat exchanger 8 Substrate (deposited material) 9 Infrared lamp 10 Rotation drive unit Fig. 1 Fig. 2

Claims (1)

[Claims] 1. In a vacuum evaporation device or a sputtering evaporation device using resistance heating method, electron beam impact method, etc., the substrate holder that fixes the object to be evaporated is used as the evaporation part, and the shaft that fixes the holder to the Pelger is used as the heat insulating part. A substrate temperature control device for a vapor deposition apparatus, characterized in that a heat pipe is configured using the extended end of the shaft as a condensing section, and the temperature of a refrigerant in a heat exchanger provided around the condensing section shaft is controlled.