JPH03207861A - Heater - Google Patents

Abstract

PURPOSE:To avoid the impurities from being restuck on a base plate, to shorten a heating time and to facilitate maintenance work by arranging a heater in the atmosphere in a device for heating the base plate to be treated before a film formation stage in the vacuum atmosphere. CONSTITUTION:When a base plate 3 to be treated is carried into a vacuum vessel 1 and placed on a first water-cooled reflector 4 via the heat insulating material 41 in a state of noncontact with a heat reflection face 42, the reflector 4 is raised to the heating position shown in a broken line. Thereby the halogen lamps 61, 62 are lighted which are arranged within one plane parallel opposed to the base plate 3 in the atmosphere side of a transparent window 5 described hereunder. This transparent window 5 is made of a quartz plate airtightly fitted to the aperture 1a of the wall face opposed to the base plate 3 in the vessel 1. The radiation heat thereof is reflected toward the base plate 3 in the heat reflection face 82 and the base plate is heated. Thereafter lights of the lamps 61, 62 are put out and the reflector 4 is lowered to the delivery position of the base plate. The base plate 3 is carried out to a film formation chamber.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is particularly applicable to surface treatment apparatuses for surface treatment of substrate surfaces, such as thermal CVD apparatuses or plasma CVD apparatuses, which treat the surface of substrates such as semiconductor wafers, etc. y to form a film on a substrate to be processed using a part of the film forming apparatus I
rcl! ! This article relates to the structure of a substrate heating device that heats a substrate to be processed as a pre-process and removes impurity gases such as moisture adhering to the substrate surface. [Prior Art] Conventionally, in order to obtain good film quality, thin-film control devices have applied processing to clean the surface of a capillary plate such as a semiconductor wafer before forming IIIllI. It is designed to allow for thorough processing. Figures 4 and 5 show an example of the structure of this type of conventional substrate heating device. FIG. 4 shows a case where the heater for heating the substrate is formed as a cast heater. For example, a heating element 21a, which is a linear electric resistor held in an electrically insulated state in a stainless steel pipe, is used to generate a predetermined amount of heat. The heater is formed by bending it in one plane to a length that allows for the desired amount of heat, and casting it with aluminum to form a flat surface on which the substrate to be processed is placed. During the heat treatment, a waiting chamber (not shown) adjacent to the front side of the vacuum chamber 1 in the evacuated vacuum chamber 1 is evacuated to almost the same pressure as the inside of the vacuum chamber 1, and the substrate to be processed is removed from the waiting chamber. After being carried into the vacuum vessel 1 through the gate valve 11 and placed on the upper surface of the casting heater 21, the gate valve 11 is closed and heating current is supplied to the casting heater 21. After the substrate 3 is heated for a predetermined period of time, the gate valve 12 is used to transport the substrate 3 into the tcm chamber adjacent to the downstream side of the vacuum container 1.
Figure 5 shows the case where the heater is configured with an infrared lamp. A heater is formed by arranging a plurality of rod-shaped infrared lamps 22 in parallel in a plane facing the Go board 3 in the vacuum container 1, and heat-insulating the substrate base 7 whose upper surface is formed as a heat-reflecting surface. The substrate 3 placed in a non-contact manner via the material 71 is heated by radiant heat. In addition, the code 23 of these people is
This is a heat reflecting plate placed behind the infrared lamp 22 to reflect the radiant heat directed away from the substrate from the infrared lamp toward the substrate surface, and to effectively use the radiant heat from the infrared lamp to heat the substrate. [Problem to be solved by the invention] In the heating device configured as shown in FIGS. 4 and 5,
Since both heaters are placed in the same vacuum container as the substrate, the gas released from the heaters re-attaches to the substrate. In addition, in the cast-in heater shown in Fig. 4, the melting point of the aluminum in which the heating element is cast is low, and in the infrared lamp heater shown in Fig. 5, cooling is poor because the bottom structure of the lamp is in a vacuum. Both the heater and the infrared lamp heater cannot provide a large amount of heat generated per unit length of the heating element, that is, the energy density, and the heat treatment time becomes long. Furthermore, there were problems such as the vacuum container having to be opened to the atmosphere every time the heater was maintained (particularly in the case of infrared lamps, which had a short lifespan and needed to be replaced regularly). The above-mentioned conventional problems are eliminated, impurity gas etc. do not re-adhere to the substrate to be processed, and the heating time required is short and maintenance work is easy. (Means for Solving I'll) In order to solve the above-mentioned lit, in this invention, a substrate to be surface-treated, such as a semiconductor wafer, is heated in a vacuum atmosphere to remove moisture etc. adhering to the substrate surface. A heating device 1 for removing impurity gases is connected to a vacuum container in which a vacuum atmosphere is formed in which a substrate is placed, and an opening is formed in which a transparent window made of a quartz plate is airtightly attached to the wall facing the substrate, and the substrate is placed in a gap. A first water-cooled reflector is provided with a heat reflecting plate placed in a non-contact state via a first water-cooled reflector, and the heat reflecting plate is water-cooled, and faces parallel to the substrate on the atmospheric side of the transparent window made of the quartz plate. A plurality of ring-shaped halogen lamps arranged concentrically in one plane and having diameters that rise from each other, and a device located on the anti-transparent window side of the halogen lamps reflect radiant heat directed toward the outside of the vacuum container from the halogen lamps toward the substrate. A second water-cooled reflector is provided with a heat-reflecting surface and the heat-reflecting surface is water-cooled.Furthermore, in this system, a plurality of rings arranged in one plane are used. It is preferable that the number of shaped halogen lamps be two, the average diameter of the smaller diameter ring being smaller than the diameter of the substrate, and the average diameter of the larger diameter ring being larger than the diameter of the substrate. By separating the space between the heater and the substrate to be processed, placing the heater in the atmosphere and the substrate in vacuum, it is possible to prevent contaminants such as gas emitted from the heater from re-adhering to the substrate. At the same time, the back surface of the heater is covered with a water-cooled heat reflector during heat processing of the substrate, and the components of the halogen lamp are protected from convection of the atmosphere around the lamp.
The radiant heat is effectively cooled by radiation cooling by heat radiation directed from the structural member toward the heat reflecting plate, increasing the amount of heat generated per unit length in the circumferential direction of the heating element (filament) of the halogen lamp, that is, the energy density, and reaching the substrate. The amount can be increased and the heating time can be shortened. Furthermore, since maintenance of the heater can be performed without exposing the vacuum container to the atmosphere, maintenance work is simplified and atmospheric pollution inside the vacuum container can be avoided. Furthermore, assuming that the number of multiple halogen lamps arranged concentrically is two, the average diameter of the small-diameter ring of these two ring-shaped halogen lamps is smaller than the diameter of the substrate to be processed, and the one on the large-diameter side is By making the average diameter of the ring larger than the diameter of the substrate to be processed, a planar heat radiation surface with a width that substantially covers the substrate surface is formed on the substrate, and a simple heater configuration can spread the entire surface of the substrate. The temperature distribution is made uniform over the entire temperature range. Furthermore, by controlling the energy density of the heating element, the uniformity of temperature distribution can be further improved. [Example] Section IWJ shows an example of the structure of a substrate heating device according to the present invention. On both walls of the vacuum container 1, partitions are provided to maintain the vacuum inside the vacuum container 1 at all times and to introduce a substrate to be processed from a waiting chamber (not shown) adjacent to the front side of the vacuum container during heat treatment. The valve 11 is adjacent to the downstream side of the vacuum vessel 1 after the heat treatment. A gate valve 12 is provided for leading out the Go board 3 to be processed to a membrane chamber (not shown). The substrate 3 to be processed is placed in the vacuum chamber 1 in a first chamber in which the upper surface 42 is formed as a heat-reflecting surface, this heat-reflecting surface is cooled with water, and the whole is moved up and down by a drive device (not shown).
A heat reflecting surface 42 is attached to the water-cooled reflector 4 through a heat insulating material 4l.
And 11 in a non-contact state! An opening h larger than the substrate to be processed 3 is formed in the wall surface of the vacuum chamber facing the substrate to be processed 3, and this opening 1a is hermetically closed by a transparent window 5 made of a quartz plate. On the back side of this transparent window 5,
Two ring-shaped halogen lamps 61 with different diameters are arranged in a plane parallel to the Go board 3. 62 are arranged concentrically and constitute an infrared heater. As is well known, a halogen lamp is a lamp in which a trace amount of halogen substances such as iodine and bromine are sealed together with an inert gas in a quartz glass container.When electricity is applied to the filament, the filament material, that is, tungsten, becomes halogen atoms or molecules. It combines to form volatile transparent tungsten halide, which does not adhere to the quartz glass container wall due to its fairly high temperature, and then dissociates again near the filament, creating a cyclical action that prevents the container wall from turning black. , it has the feature of little decrease in luminous flux. This halogen lamp 61. A second water-cooled reflector 8 is provided behind the halogen lamp 62 and includes a heat reflecting surface 82 that reflects the radiant heat directed toward the outside of the vacuum container from these halogen lamps toward the substrate 3, and this heat reflecting surface is water-cooled. It is being done. The operation of the gap heating device that heats the substrate will be explained below.
The gate valve 1l is opened when a waiting chamber (not shown) adjacent to the front stage side of the vacuum container 1 is evacuated to almost the same pressure as the vacuum container 1, and the substrate 3 to be processed in the waiting chamber is removed from the vacuum container 1. The first water-cooled reflector 4 is placed in a non-contact state with the heat reflecting surface 42 via the heat insulating material 41. The number of substrates to be processed is 1! When the gate valve 1l is closed, the first water-cooled reflector 4 rises to the heating position shown by the broken line. When the first water-cooled reflector 4 reaches the heating position, the halogen lamp 61. 62 are turned on at the same time, and the substrate to be processed is heated. When the prescribed heating is completed, the halogen lamp 61. 62 is turned off, the first water-cooled reflector 4 is lowered to the substrate transfer position, and the gate valve 12 is turned off.
is opened, and the substrate to be processed 3 is adjacent to the rear stage of the vacuum container 1. It is carried out to a membrane chamber (not shown). Processed Go board 3
Although not particularly shown in the drawings, the transport mechanism section is configured so that the Go board 3 to be processed can be transported within the vacuum container 1 or through the waiting chamber, the vacuum container L, the membrane chamber, and the partition valves 11 and 12. It is installed in a separate vacuum container located at the Figure 2 shows a halogen lamp 61. 62 and the substrate to be processed 3 are shown. When the average diameter A of the inner halogen lamp 61 is smaller than the diameter B of the substrate 3, and the average diameter C of the outer halogen lamp 62 is larger than the diameter B of the substrate 3, when a large diameter substrate of 8 inches in diameter is used. However, as shown in Figure 3, the temperature distribution can be made uniform over almost the entire substrate surface. As shown by the solid line in the figure, if the energy density (heat amount per unit circumferential length of the heating element) of the inner halogen lamp 61 is made smaller than that of the outer halogen lamp 62, a more uniform temperature distribution can be obtained. Can be done. Note that the energy density in the figure shows relative values. [Effects of the Invention] As described above, the present invention provides a heating device that heats a substrate to be surface-treated, such as a semiconductor wafer, in a vacuum atmosphere and removes impurity gas such as moisture adhering to the substrate surface. The substrate is placed in a non-contact state through a gap with a vacuum container in which a vacuum atmosphere is formed in which the substrate is exposed, and an opening is formed in which a transparent window made of a quartz plate is airtightly attached to the wall facing the substrate. a first water-cooled reflector including a heat reflecting plate that is cooled by water;
A plurality of ring-shaped halogen lamps with diameters rising from each other are arranged concentrically in a plane facing parallel to the substrate on the atmosphere side of the transparent window made of the quartz plate, and a plurality of ring-shaped halogen lamps are arranged opposite to the transparent window of the quartz plate. However, since the structure includes a heat reflecting surface that reflects radiant heat directed from the halogen lamp toward the outside of the vacuum container toward the substrate, and a second water-cooled reflector in which the heat reflecting surface is water-cooled, the substrate to be processed can be An infrared heater consisting of a plurality of ring-shaped halogen lamps is placed in a separate space, and re-contamination of the heater by gas emitted from the heater is completely removed. Forced cooling of the heat reflecting surface that reflects outward radiant heat toward the substrate to be processed is possible, and the structural members of the halogen lamp can be cooled by convection of the atmosphere around the lamp.
Since it is effectively cooled by radiation cooling by heat radiation directed from the structural member toward the forcibly cooled heat reflection plate, it is possible to increase the heating power supplied to the halogen lamp and shorten the heating time of the substrate to be processed. ．． In addition, the number of ring-shaped halogen lamps arranged in one plane is two, and the average diameter of the ring on the small diameter side is smaller than the diameter of the umbilical cord, and the average diameter of the ring on the large diameter side. Relatives! By making the diameter larger than the substrate, a substantially planar heat radiating surface is provided to the substrate, a uniform temperature distribution can be obtained over the entire substrate surface, and the heating device is also simplified. Ru. By adjusting the energy density of the two halogen lamps, a more uniform temperature distribution can be obtained. Furthermore, the device structure according to the present invention makes it possible to maintain the heater without opening the vacuum container to the atmosphere, which simplifies maintenance work and shortens work time. In addition, air pollution inside the vacuum container is avoided, and the throughput of surface treatment equipment that includes a heating device as a component is improved.

[Brief explanation of drawings]

1'@ is a vertical cross-sectional view showing an embodiment of the structure of the substrate heating device according to the present invention, and FIG. 2 is the diameter of the substrate to be processed when the heater of the heating device is composed of two ring-shaped halogen lamps. and the average + of each halogen lamp! Figure 3 is an explanatory diagram showing the dimensional relationship with the diameter, Figure 3 is an embroidery diagram showing the temperature distribution on the surface of Go i when heat treatment is performed with the heater configured as shown in Figure 2, Figures 4 and 5 are Each is a longitudinal cross-sectional view showing an example of the configuration of a conventional substrate heating device. 1: Vacuum container, 1a: Opening, 3: Go board, 4: First water-cooled reflector, 5: Transparent window, 8: Second water-cooled reflector,
41: Heat insulating material, 42: Heat reflecting surface, 61, 62: Halogen lamp, 82: Heat reflecting surface. ~4-1τ'A<E3<C Fig. 2 Visibility (phase light value) Fig. 4

Claims (1)

[Scope of Claims] 1) A heating device that heats a substrate to be surface-treated, such as a semiconductor wafer, in a vacuum atmosphere and removes impurity gas such as moisture adhering to the substrate surface, the heating device heating the substrate to be subjected to surface treatment, such as a semiconductor wafer, in a vacuum atmosphere to remove impurity gases such as moisture attached to the substrate surface. A vacuum container is provided with an opening in which an atmosphere is formed and a transparent window made of a quartz plate is airtightly attached to the wall facing the substrate, and a heat reflecting plate is placed on which the substrate is placed in a non-contact state through a gap. a first water-cooled reflector in which the heat reflecting plate is water-cooled; and a plurality of water-cooled reflectors having different diameters and arranged concentrically within a plane facing parallel to the substrate on the atmospheric side of the transparent window made of the quartz plate. a ring-shaped halogen lamp; a heat reflecting surface located on the opposite side of the halogen lamp to reflect the radiant heat directed toward the outside of the vacuum container from the halogen lamp toward the substrate; 2. A heating device comprising: 2 water-cooled reflectors. 2) In the heating device according to claim 1, the number of the plurality of halogen lamps arranged concentrically in one plane is two, and the average diameter of the ring on the smaller diameter side is smaller than the diameter of the substrate to be surface treated. A heating device characterized in that the average diameter of the small ring on the large diameter side is larger than the diameter of the substrate to be surface treated.