JPS5914634A - Substrate heating apparatus - Google Patents

Abstract

PURPOSE:To control temperature of substrate with a high accuracy during plasma discharge by forming a cylindrical substrate heating apparatus and arranging a heater and a piping for cooling in close contact with the internal surface of cylindrical portion. CONSTITUTION:The covers 302a, 302b of heating apparatus are placed in contact with the internal surface of the basic materials 301a, 301b of light sensitive drum and the heaters 303a, 303b, 303c and the tubes 304a, 304b for flowing coolant are arranged alternately at the internal surface. When such a substrate heating apparatus is used, temperature of basic material can be kept constant during deposition of amorphous Si on the drum by the plasma CVD method and obtained the drum assures excellent light sensitivity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a substrate heating device for plasma OVD, in which a heater and a cooling tube are installed inside the device, and the substrate is heated and cooled even during plasma discharge. The substrate heating device K11l is designed for highly accurate temperature control.

In recent years, many thin films, including amorphous silicon (hereinafter referred to as α-8i), silicon oxide films, and silicon nitride films, have come to be produced by plasma OVD.

When forming a film of the above-mentioned materials by the plasma AVN method, an example of a photosensitive drum manufacturing method using a substrate heating A-8T at 150 to 650° C. is used as an example.
An overview of film formation using this method and the method of heating the substrate will be explained.

FIG. 1 is a schematic diagram of a plasma ovDIItft for producing a photosensitive drum. In the same figure, the base material 102 is a quartz Channo Kuichi 1103Fi high frequency coil, 104 is a high frequency oscillator, 105 is a pump for the air, 106 is a shaft, and 107 is a Tanabata. 1st
Using the necessary equipment, a photosensitive drum of α·′Bi is prepared in the following manner.

Approximately lX inside the chamber/(-102
The temperature of the base material on the cylinder is maintained at 230 to 250° C. while evacuating to 1G=1 orr. The substrate is heated by a heater installed in a substrate heating device, which will be described later. When the temperature of the heater reaches a predetermined temperature, monosilane (84H,) argon (Ar),
A mixed gas of Diporan (B, H,) is heated to a pressure of approximately ITOr? ', introduce it so that it becomes. Also, the flow rate ratio of diporane to monosilane is approximately 1×10'.

In this state, when a high frequency discharge is caused in the chamber by the high frequency oscillator 104, the introduced gas is decomposed and the base material 10
An α-8i film is formed on the surface of 1.

The substrate is rotated by a motor 107 through a shaft 106 in order to obtain uniformity in film thickness. Rotation speed Fi: Approximately 1 per minute
It is 0 rotation.

FIG. 2 is a diagram A schematically showing the appearance and cross-sectional structure of a drum base material set in the substrate heating device.

In FIG. 2, 201α and 201b are the base materials of photosensitive drums, 201a is an external view thereof, and 201b is a sectional view.

Also, 202α, 202b and 203t- are heated! ! 2 position is shown, 202α is an external view of the cover, 20
2 Ru.

A cylindrical base material 201α is set in a substrate heating device represented by 202α, 202b, and 203 in Figure 2, and a-si is deposited on the surface of the base material while heating.

In the above explanation, the explanation was given using a photosensitive drum as an example, so a cylindrical base material is set in a cylindrical substrate heating device. On the other hand, there are also cases where a flat substrate is set in contact with a flat substrate heating device and deposition is performed using plasma ('VD), but the principle is the same.

When performing plasma OVD deposition while heating using the substrate heating device shown in FIG. 2 or a flat substrate heating device, the conventional substrate heating device has a major drawback. The problem is that it is difficult to control the temperature of the substrate during plasma discharge.

Even if the substrate is heated to a certain temperature, for example 200° C., and plasma discharge is started, the temperature will rise and will not be constant because the plasma itself has energy.

In particular, when depositing α-8i using the cylindrical base material for the photosensitive drum shown in FIG. 2 with the arrangement shown in FIG.
The temperature rise is huge. One of the reasons, high frequency electrode 1
This is because 03 surrounds the base material, trapping the plasma and increasing the density, and also because Fi requires a long debossing process of 10 hours or more.

Therefore, if the landing high frequency power is strong, the initial
Even if the substrate heating device was heated to 0℃ and the heater of the substrate heating device was turned off at the same time as the plasma discharge started, the temperature of the substrate rose due to the plasma energy, and the MIC for 10 minutes of 1JQ was 250℃.
There are cases where it is more than that.

What are the characteristics of films produced using plasma CVDK?

It is often affected by the temperature at the time of deboref 1, and even when depositing an a-Bi film for a photoconductor, if the temperature exceeds 250°C, hydrogen in the film will be desorbed, resulting in poor charging performance. I know that.

However, in conventional substrate processing equipment, the temperature rises rapidly, and the resulting film does not reach the desired level. ! ! The disadvantage was that it was not possible to obtain

The present invention eliminates such drawbacks, and its purpose is to perform accurate temperature control in a substrate heating device.

FIG. 3 schematically shows the appearance and cross section of the present invention. In the figure, 301α represents a cross section of 301b#'i of the base materials of photosensitive drums 301α and 3016Fi. In addition, 302α is the appearance of the substrate heating charge cover,
302 b 1- is a cross section of the substrate heating device cover.

ζ et al., 3Q3 a,, 505. b, 30
3 C・・・・・・・・・ is a heater for heating the substrate,
304α, 5O4b, . . . are tubes through which coolant for cooling the substrate flows.

The present invention will be explained with reference to one embodiment. The photosensitive drum has an outer diameter of 80wnφ, a length of 500m5+, and a base material thickness of ζId5wa. Therefore, the outer diameter of the cover of the substrate heating device was 74 tmφ, and the heater was of a sheath type and was wound around the cover with a pitch of about 201111 mm. In front, the tube through which the refrigerant flows is an internal 5 mm copper pipe.
It was wound in contact with the cover in the same way as the heater at a pitch of 0.

Using this substrate heating device, an n, -si photosensitive drum was produced. First, the temperature of the aluminum substrate was raised to 200° C. using a heater while the chamber was being evacuated, a reaction gas was introduced into the chamber, and the heater was turned off at the same time as high-frequency discharge was started. Furthermore, water at about 70℃ was added to the refrigerant pipe for 11 minutes.
/min. In addition, high frequency power FiO, 8K W
It's thick. Deposition was carried out in this state for about 8 hours, but the temperature of the substrate only rose to 205°C. This value is very small compared to the 250° C. increase in the conventional method, and the accuracy of temperature control has been greatly improved.

According to experiments, it was confirmed that increasing the high-frequency power increases the temperature of the base material, but by lowering the temperature of the coolant, it is possible to keep the temperature almost constant during papermaking and deposition.

Further, similar effects can be obtained by using not only water but also an organic liquid as the refrigerant.

As described above, by using the substrate heating device of the present invention, the temperature of the substrate during deposition could be kept constant, and the photosensitive properties of the resulting drum were also good. As described above, the effects of the present invention are enormous, and the principle of the present invention can be used for sputtering, vapor deposition, and flat plate type substrate heating in OVD equipment, and its range of application is extremely wide.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a plasma 0VD device for producing photosensitive drums, FIG. 2 is a diagram schematically showing the external appearance and cross-sectional structure of a substrate for a drum installed in a substrate heating device, and FIG. 3 is a diagram schematically showing the appearance and cross section of the present invention. 101... Photosensitive drum base material 102... Quartz chamber 103... High frequency coil 104... High frequency oscillator 105... Exhaust pump 106 ...Shaft 107...Motor 301α-b...Photosensitive drum base material 302α-b
...... Board heating IT cover 303cLA-c...
...Heater 304a-b...Pipe plate through which refrigerant flows Applicant Suwa Seikosha Co., Ltd. 1st Zuzuki 2F! ” Figure 3

Claims (1)

[Scope of Claims] 1) A substrate heating device for plasma OVD, characterized in that a heater and a cooling tube are provided inside the device. 2) The substrate heating device according to claim 1, wherein the substrate heating device f has a cylindrical shape, and a heater and cooling piping are arranged in contact with the inside of the cylinder.