JPS58199047A - Vacuum heating device - Google Patents

Abstract

PURPOSE:To obtain a device that can heat uniformly using a material that does not liberate gas even in high degree of vacuum and does not react with the sample by assembling a strip of sapphire using a spacer made of sapphire. CONSTITUTION:A sample placing layer made by arranging strips of sapphire plate side by side, an intermediate layer having a spacer 43 made of sapphire that separates parallel running heater wires 45, a lower layer 46 made by placing strips of sapphire side by side and a holding jig that holds above-mentioned three are provided. A material such as Mo etc. which is heat resisting and does not liberate gas can be used for the holding jig. As the sapphire plates of the layer 46 is laminar, and as the combination thereof with the spacer 43 is made on the side face, they do not receive concentrated thermal stress and can bear considerable thermal shock. Especially when the width is >=7mm., they are hardly destructed even by repetition of heating to above 1,000 deg.C. As they are mostly made of sapphire, gas is not liberated when heated in high degree of vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for heating a sample in a high vacuum.

In the fields of vapor deposition and molecular beam epitaxy, samples are heated under high vacuum. Especially in molecular beam epitaxy, 10-
” With ordinary heating equipment for heating to over 700°C in an extremely deep atmosphere of approximately Torr, gas is released from the equipment itself, making it difficult to maintain a vacuum state. The materials used are as follows, and the structure as shown in Fig. 1 or Fig. 2 is adopted.

However, with the structure shown in Figure 1, it is difficult to uniformly heat the sample with -VC, and in Figure 2, although relatively uniform heating can be achieved up to -Ll, for example, in the case of a sample or a silicon single crystal, 1 (111) (At temperatures above 1°C, both react and cannot be used for practical purposes, which is a drawback.) The present invention has been developed to further react with the sample without emitting gas even in high vacuum rC. We have developed a device that can heat the material uniformly using unique materials, and by assembling strips of sapphire with sapphire spacers, we have completed a device that does not have these drawbacks.In other words, sapphire It has the excellent features of low vapor pressure, instant insulation, high mechanical strength, low reactivity with other materials, and good thermal conductivity.However, thermal shock resistance K 9 points Therefore, it was successfully put into practical use as a device by making it into strips to release the thermal stress.The strips of sapphire were arranged in consideration of the dispersion state of heat content, the thermal stress of the sapphire, etc. The width shall be 7m or less.

By fitting the spacer at the adjacent contact portions, the 1'ft1 could be made to have even less damage due to stress.

An embodiment of the present invention will be explained with reference to the figures in J.So.V. Reference numeral 31 denotes a sample mounting layer in which a plurality of strip-shaped ear rings for trial loading are arranged so as to be in contact with each other.

A sapphire spacer constituting the intermediate layer separates the sample mounting layer 31 from the lower part 1-33, and also serves to hold the tungsten heater wire 34. Similarly, K 1ml l-shaped Naphia are lined up.

35 is a holding jig for holding these assemblies.

Combination of spacer and strip-shaped sapphire plate iE+! :
An example of the structure is shown in FIG. Figure 4 shows the sample mounting-tilt
This is a diagram showing the relationship between each layer of the intermediate layer and the lower layer. Hole V to be made (sapphire spacer 4 in the middle layer)
The protrusion 44 provided in the downward direction of E of 3 is fitted into the protrusion 44. The heater 45 is held so as to wrap around each spacer 43. These combinations are held together by a holding jig 48, and as a whole constitute a part of the heater of the device of the present invention. The holding jig 6 may be made of, for example, molybdenum or the like, which has side heat properties and does not emit scum. In the VC of the present invention, the sapphire plate of the lower layer of the sapphire plate for sample loading is a plate-shaped body, and since the combination with the spacer is performed on the side, the heat Ic;
It does not receive concentrated force and can withstand considerable thermal shock VC. Especially if the width is 7m or less, Kl or 1 (
141111: Even if repeated heating is repeated, it will not be destroyed.

My father is made of sapphire, so the temperature is 10-'Torr.
Even when heated in an ultra-high vacuum, the ultra-high vacuum state can be easily maintained without releasing adsorbed gas. Furthermore, sapphire does not react with many other materials, so even if it is heated to 1°C or higher, it will not react with silicon single crystals. Therefore, even if the sapphire plate is damaged, it is just a series of plate-like bodies, so it is easy to replace, and changing the @ of the sapphire plate means Since the pitch of the heater can be changed, any temperature distribution can be obtained.

Hereinafter, an example using this invention will be explained.

Size 1# + sapphire plate of mounting layer and lower layer width 4-1
Use a board with a length of 1O()■ and a thickness of 2 pieces.

25 pieces of stiffness were lined up to form a sample mounting layer and a lower layer of 17.

A sapphire spacer of the shape shown in Fig. 4 is used, and a heating element with the structure shown in Fig. 3 is used. A heater and a holding jig KFi molybdenum plate were used. Place a KP type 5~1OΩ- single crystal silicon wafer f on the sample mounting W layer,
Apply a current of 15 to the heater, fo-'Torr
When the silicon wafer was heated to 1100°C under vacuum, the a! The temperature of the ridge was within the range of 110°C.

Gaigin speed #1lloo℃ in flO minutes, temperature drop tJ
I let it cool silently over 50 times, but the sapphire t-t
It wasn't damaged at all. In addition, no reaction with the silicon wafer was observed, and the degree of vacuum did not decrease [7].

The apparatus of the present invention has features not found in conventional vacuum heating apparatuses, that is, it is capable of uniform heating without gas release from the member, and has excellent effects such as no reaction with the sample.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a conventional heating device; Fig. 2 is a perspective view of main parts of a conventional heating device that heats a sample by attaching it to a Mo block; Fig. 3 is a perspective view of a heating device of the present invention; FIG. 4 is a diagram showing in detail a part of the structure of the device shown in FIG. 3. Inventor Tsuyoshi Takahashi - Inventor Perspective Axis - Output 1 person Toshiba Ceramics Co., Ltd. Applicant Tokyo Shibaura Electric Co., Ltd. Figure 1, Figure 1

Claims (4)

[Claims] (1) A sapphire spacer (r 44) that isolates the sample mounting layer which is lined up with sapphire plates in the shape of a sapphire plate, a sapphire spacer that isolates the heater wire that runs almost parallel to it, a lower ml- layer in which strip-shaped sapphire plates are lined up, and the three layers mentioned above. A vacuum heating device characterized by comprising a mechanism for holding. (2) The vacuum heating device IIT according to claim 1, wherein the strip-shaped sapphire plate serving as the sample mounting layer has a width of 7 mm or less. (3) The spacer of the intermediate layer is made of sapphire and has a VC structure so as to be held at the contact portion of adjacent sapphire plates of the sample mounting layer.+Claim 1. Vacuum heating device as described. (4) A patent characterized in that the projections are provided in the vertical direction of the sapphire layer of the intermediate layer, and the structure is a combination of the projections and strip-shaped sapphire plates having matching holes or depressions. Vacuum heating device as described in section.