JPH01243428A - surface treatment equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a surface treatment apparatus for treating solid surfaces, and has characteristics of no damage, high selectivity, and anisotropy, which are particularly suitable for semiconductor device manufacturing. The present invention relates to a surface treatment apparatus capable of performing surface treatment.

[Conventional technology]

Low-energy particles (atoms) ejected from the nozzle.

Etching using a beam of molecules, ions, etc.

Conventional equipment for surface treatment such as deposition, surface modification (oxidation, nitridation, etc.) and impurity doping is for example
It was as shown in Figure 1 of No. 2-35521. This technique involves heating a gas to form active particles, ejecting the active particles into a vacuum to form a beam of active particles, and treating the surface of a sample with this beam. Here, a beam is an anisotropic flow of particles in which collisions between particles constituting the flow can be effectively ignored.

[Problem to be solved by the invention]

The above conventional technology does not take into account the temperature distribution within the nozzle. In the above conventional technology, a heater is provided around the nozzle as a nozzle heating means for activating the gas. In this case, the temperature distribution of the nozzle is determined by the amount of heat supplied from the heater, the thermal conductivity of the nozzle, the amount of heat released from the nozzle to the gas in the nozzle, and the amount of thermal radiation from the nozzle6, especially near the exit of the nozzle. In this case, the amount of heat released into the gas inside the nozzle and the amount of thermal radiation is larger than in other parts of the nozzle, so either increase the amount of heat supplied to the vicinity of the nozzle outlet or do not reduce the amount of thermal radiation. As a result, the temperature near the nozzle outlet will be lower than the temperature in other parts of the nozzle. In this case, the energy of the beam ejected from the nozzle also becomes low, posing a problem that efficient surface treatment cannot be performed.

The results of actually examining the energy of the beam were as shown in Figure 5. Figure 5 shows that 1 for the voltage applied to the heater.
These are the results of measuring the vibration temperature ('rv) of Cl22 and the nozzle temperature (Tro, Tr.) when 5 sccm of Cu2 was ejected from a nozzle with an inner diameter (diameter) of 2 mm. Tt
C is a point 20mm deep from the nozzle exit, T. is the nozzle temperature measured at a point 2 mm deep from the nozzle outlet. As shown in FIG. 5, the temperature Tr0 near the nozzle outlet is equal to the temperature T of other parts of the nozzle. It is lower than . Furthermore, the oscillation temperature TV of Cu2 is approximately close to Tto, and it was found that in order to increase the energy of the beam, it is necessary to increase the temperature near the exit of the nozzle.

[Means to solve the problem]

The above object is achieved by increasing the amount of heat supplied to the vicinity of the nozzle outlet or a part thereof, or decreasing the amount of heat released, thereby increasing the temperature in the vicinity of the nozzle outlet.

[Effect]

In order to increase the energy of the beam, it is sufficient to increase the temperature near the nozzle exit. Here, the vicinity means the range from the nozzle exit to the depth of approximately Q. Usually, as shown in FIG. 5, it is good for Q to be about the same as the nozzle exit diameter.

Specifically, it varies depending on the processing conditions, and
It can be 2 or even 10 times. Further, depending on the processing conditions, it may be desirable for Q to be about the mean free path Q of the molecules in the nozzle or about 10 times the mean free path Q.

The energy of molecules in the beam includes translational energy,
There is vibrational energy, etc. When using translational energy for surface treatment, it is desirable that the translational energy of the molecules in the beam be high. In this case, 30% of the molecular translational energy is lost in a single collision with a cold surface, so (Journal of Chemical Physics 84° 1939 (1986) (J, Che+s,
Phys.

84.1939 (1986)) and Journal of Vacuum Science and Technology B3゜147
4 (1985) (J, Vac, Sci, Tech
nol.

B3.1474 (1985)), Q as the neighborhood,
It is desirable to take the heat and finally hit the hot part of the nozzle. On the other hand, when using vibration energy for surface treatment,
All you have to do is increase the vibrational energy of the molecules in the beam. Since the vibrational energy of a molecule increases by only 7% in a single collision, (Physical Repulsors 55.1904 (
1985) (Phyg, Rev. Lett, 5
5.1904 (1985)), it is preferable to take Q2 as the neighborhood and keep the number of collisions with the high temperature part inside the nozzle at about 10 times.

The mean free path of molecules in the nozzle changes depending on the gas pressure at that location and the type of gas. The gas pressure at the nozzle position is usually 10 -2 to 10 Torr (however, the pressure may be other than this depending on the case).

), at this time, the mean free path is about 0.5 to 5X10-', the above Q is 0.5 to 5X10-'cm, and Q2 is 5X5XIO-3cm.

〔Example〕

[Example 1] FIG. 1 is a schematic diagram showing an example of the present invention. A substrate support 12 is provided in a reaction tank 11 that can be evacuated,
A substrate 13 is supported thereon.

A gas introduction pipe 15 is provided that faces the substrate 13 and penetrates the wall of the reaction tank 11, and has a nozzle 14 at its tip whose ejection direction is directed toward the substrate 13. It is possible to irradiate the nozzle 14 with light 16d from a light source 16a installed outside the reaction tank 11 through a lens 16b and a window 16c. Especially light 1
By focusing the light 6d near the exit of the nozzle 1-4, the vicinity of the exit of the nozzle 14 can be heated.

In this embodiment, chromium carbonyl is used as the reaction gas, mixed with argon gas, and introduced from the gas introduction pipe 15. After the reaction gas is vibrated or decomposed near the exit of the nozzle 14, it becomes a beam and enters the sample, forming a metal thin film. A xenon lamp, a high-pressure mercury lamp, or the like can be used as the light source 16a, and it is necessary to select a suitable one depending on the material of the nozzle 14. Furthermore, if an excimer laser is used as the light source 16a, the device will be complicated;
The vicinity of the exit of the nozzle 14 can be heated to a high temperature instantaneously, a high-energy beam is formed, and the surface treatment ability is further enhanced.

According to this embodiment, since the temperature in the nozzle other than the part where the light is focused does not become too high, it is possible to prevent the reaction gas from being decomposed and forming a metal film in the part other than the nozzle outlet. Furthermore, since the temperature near the exit of the nozzle can be raised to an extremely high temperature, the high-energy beam can improve the surface treatment ability. Furthermore, since no electrons are used, fewer ions are mixed into the beam, and no charge-up occurs in the nozzle or substrate.

[Example 2] FIG. 2 is a schematic diagram showing a second embodiment of the present invention.

A substrate support 22 is provided in a reaction tank 21 that can be evacuated, and a substrate 23 is supported on the 6-substrate support 22. A substrate 23 is provided above the substrate 23 through a wall of the reaction tank 21, and has an ejection direction directed toward the substrate 23 at the tip. A gas introduction pipe 25 having a nozzle 24 is provided. A filament 26 is provided below the nozzle 24.

By heating and applying a bias voltage, the vicinity of the exit of the nozzle 24 is irradiated with electrons. As a result, the vicinity of the exit of the nozzle 24 is selectively heated. Here, using silicon as the substrate 23, one reaction gas F2 is mixed with argon gas and introduced from the gas introduction pipe 25. Near the exit of the nozzle 24, the F2 collides with a part whose temperature has increased due to electron irradiation, and decomposes into F. The F generated by the decomposition is ejected into the vacuum, becomes a beam, and then enters the substrate 23, where it enters the substrate. Perform etching.

In this example, electron irradiation was used as the nozzle heating method. This keeps the temperature low in areas other than the vicinity of the nozzle outlet, suppresses the generation of F, and
This can prevent the nozzle from being etched. Furthermore, since the device configuration of this embodiment is simple, it is easy to downsize the device. Furthermore, since it uses less energy than plasma etching or the like, it causes less damage to the surface, making it possible to manufacture semiconductor elements with good characteristics.

[Example 3] FIG. 3 is a schematic diagram showing a third embodiment of the present invention.

A substrate support 32 is provided in a reaction tank 31 that can be evacuated, and a substrate 33 is supported on it. The wall of the reaction tank 31 is penetrated above the substrate 33 .

A gas introduction pipe 35 having a nozzle 34 whose ejection direction is directed toward the substrate 33 at its tip is provided. The nozzle 34 is provided with an electrode, and by passing a current between the electrodes, the nozzle 3
Perform heating in step 4. The reaction gas is ejected from the heated nozzle 34 into a vacuum, becomes a beam, and then enters the substrate 33.
Perform surface treatment.

In this example, electrical heating was used as the nozzle heating method. As a result, the nozzle could be heated efficiently, and a drop in temperature near the nozzle outlet could be suppressed. Furthermore, in this embodiment, by modifying the material of the nozzle, it is possible to further increase the temperature near the nozzle outlet.

The amount of heat generated during electrical heating is proportional to the resistance value.

Therefore, by increasing the resistance value near the nozzle exit, the temperature near the nozzle exit can be increased. Further, even if the nozzle is made of a semiconductor, it is possible to reduce the temperature in the vicinity of the nozzle outlet without partially changing the material of the nozzle. Semiconductors have a property that their resistance increases as the temperature decreases, so the amount of heat generated increases in the lower temperature parts. That is, by making the nozzle from a semiconductor, the temperature distribution in the nozzle can be reduced.

[Embodiment 4] FIG. 4 is a schematic diagram showing a fourth embodiment of the present invention. A substrate support 42 is provided in a reaction tank 41 that can be evacuated, and a substrate 43 is supported thereon.A substrate 43 is supported above the six substrates 43 by penetrating the wall of the reaction tank 41.

A gas introduction pipe 45 having a nozzle 44 whose ejection direction is directed toward the substrate 43 at its tip is provided. A heater 46 is spirally provided around the nozzle 44 to heat the nozzle 44. The number of turns per unit length of the heater 46 is increased near the exit of the nozzle 44, so that the temperature near the exit can be maintained higher than in other parts. Furthermore, a hemispherical mirror 47 is provided around the exit of the nozzle 44, and reflects thermal radiation from the vicinity of the exit of the nozzle 44, thereby preventing a drop in temperature near the exit.

In this embodiment, since a spiral heater is used as the nozzle heating method, the temperature distribution of the nozzle can be easily controlled by changing the number of turns of the heater. Further, the mirror 47 has a hole through which the beam passes, and by changing the diameter of this hole, it is also possible to improve the directivity of the beam.

Although several embodiments have been described above, various other methods can be considered in order to prevent the temperature near the nozzle outlet from decreasing. The thermal conductivity of the nozzle is 240W-m-'・m
It is also possible to select aluminum with a value of -', gold with an emissivity of 0.02, etc.

It goes without saying that it is also possible to combine some of the above embodiments.

Furthermore, various reaction gases may be used.

Oxidation of Si, etc. is possible by using 026 or X e
F2. Etching can also be performed using C12t F2 or the like. Such surface treatment techniques are particularly useful in the manufacture of semiconductor devices and organic material devices because they do not damage the surface and allow directional treatment.

〔Effect of the invention〕

According to the present invention, since a beam with high energy can be formed, surface treatment ability can be improved. Furthermore, since the surface treatment uses a low-energy beam, it is possible to manufacture semiconductor elements with good characteristics.

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Substrate, 14... Nozzle, 15... Gas introduction pipe, 16
a... Light source, 16b... Lens, 16c... Window,
16d...light.

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Claims (1)

[Scope of Claims] 1. A reaction tank that can be evacuated, a substrate support disposed inside the reaction tank, and an ejection direction that penetrates the substrate supported by the substrate support and the wall of the reaction tank and has a jet direction at the tip. An apparatus comprising a gas conduit having a heatable nozzle directed toward the substrate, characterized in that the temperature of the nozzle near the outlet or a part near the outlet is equal to or higher than the temperature of the other part of the nozzle. surface treatment equipment. 2. The surface treatment according to claim 1, comprising a light source and an optical system capable of irradiating light near the exit of the nozzle or a part of the near the exit, and heating the nozzle with the light. Device. 3. The surface treatment apparatus according to claim 2, wherein the light source is a laser. 4. The surface treatment apparatus according to claim 1, further comprising an electron source capable of irradiating the vicinity of the exit of the nozzle or a part thereof with electrons, and the nozzle is heated by the electrons. 5. The surface treatment apparatus according to claim 1, wherein the nozzle is heated by being energized. 6. The surface treatment apparatus according to claim 5, wherein the nozzle is made of a semiconductor. 7. The surface treatment apparatus according to claim 1, comprising two or more nozzle heating devices, one or more of which selectively heats the vicinity of the nozzle outlet or a part thereof. 8. Equipped with a heater in a spiral shape with the nozzle as the axis,
2. The surface treatment apparatus according to claim 1, wherein the number of turns per unit length of the heater is greater near the nozzle outlet or a part thereof. 9. The surface treatment apparatus according to claim 1, wherein the nozzle is made of a material having an emissivity of less than 0.1. 10. The above nozzle has a thermal conductivity of 100W・m^-^1
- The surface treatment apparatus according to claim 1, characterized in that it is made of a substance having a value larger than K^-^1. 11. The surface treatment apparatus according to claim 1, further comprising a mirror provided around the outlet of the nozzle.