JPS6178436A - Optical exciting process apparatus - Google Patents

Abstract

PURPOSE:To conserve reaction gas, by providing a reaction gas introducing apparatus and a beam incident apparatus for irradiating reaction gas with laser pulse beam to generate optical reaction and performing the introduction of the reaction gas into a reaction chamber and the irradiation of beam in definite time relation. CONSTITUTION:When either one of reaction gas pulse jet valves 7, 8 is turned ON by a control apparatus 16 and the pressure in a reaction chamber 1 is raised by the introduction of reaction gas, laser pulse beam is irradiated through a beam incident window 6. When the pulse jet valve 7 or 8 is turned OFF and unreacted gas in the reaction chamber 1 is exhausted and the pressure in the reaction chamber 1 is lowered, the analysis of the surface state of a substrate 3 is performed by in-process monitors 13, 14. By shortening the ON- time of each pulse jet valve, the flow amount of reaction gas can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a photo-excited process equipment ffK such as photo-CVD, photo-etching and photo-epitaxy used in semiconductor process technology such as VLSI.

BACKGROUND OF THE INVENTION With the development of VLSI technology, a photoexcitation process, which has features such as low temperature, no damage, and reaction selectivity, is attracting attention as a new semiconductor manufacturing technology.

Incidentally, various optical meters are used in the optical excitation process that is currently being researched, and among them, many studies are being conducted using an ekinmarer laser and a pulsed C02 laser. These lasers emit light repeatedly and intermittently, ranging from several times to hundreds of times per second. Therefore, the time during which the laser actually emits light is approximately one millionth of a second per second. However, in conventionally researched photoexcitation process devices, the reaction gas is continuously supplied to the reaction chamber even though the laser emits light intermittently and the light emission time per second is extremely short. Since the laser emission time (per second) is extremely short and the subsequent reaction time is also extremely short, most of the reaction gas that is continuously flowing is wasted without being irradiated with light, which increases the load on the pump. Not only does this increase accordingly, but the normally used reaction gas is a toxic gas, so its disposal also becomes a problem. In an atmosphere where a reaction gas is constantly present at 10-' to 10' Pa or higher, in-process monitors that require high vacuum, such as RWE) i:D% surface analyzers and mass spectrometers, cannot be used. . In addition, in the case of 4-no-good formation, in addition to film formation on the substrate, glands are formed on the light introduction window into the device, resulting in poor light transmittance and insufficient light transmission to the vicinity of the substrate. A problem arises in that light no longer reaches the target. When forming a film by changing the composition using two or more types of reactive gases,
It is difficult to rapidly replace the reaction gas in the reaction chamber by normal manual operation or by operating a pneumatic valve, and it is difficult to rapidly change the composition of the film on the substrate. Furthermore, when the reaction chamber is filled with reaction gas and laser is irradiated in one seat,
There is a problem in that the reaction proceeds more than necessary in the gas phase and grows into fine particles, which are deposited on the substrate and deteriorate the quality of the film to be formed.

Problems to be Solved by the Invention Therefore, the present invention solves the problems associated with the continuous and steady supply of reaction gas in conventional photoexcitation process equipment, the increase in pump load, the adhesion of films to the light introduction window, and the The purpose is to solve the problem of particle generation.

'Another object of the present invention is to make it possible to form a film having a steep compositional change.

In order to achieve the above object, the present invention provides a reaction gas introduction device that introduces a reaction gas into a reaction chamber, and a laser pulse light that irradiates the reaction gas introduced into the reaction chamber to cause a photochemical reaction. A photoexcitation process apparatus is provided, which is characterized in that it has an introduction device, and is configured to carry out the introduction of a reaction gas into a reaction chamber and the light irradiation for a certain period of time.

In the optical excitation process apparatus of the present invention, it is preferable that a plurality of reaction gas introduction devices be provided to introduce different reaction gases into the reaction chamber, and one or several "lasers" from the light introduction device may be provided. For each pulse irradiation, six reactant gases can be delivered from different reactant gas introduction devices. In addition, in the process apparatus according to the present invention, the reactive gas introduced from the reactive gas introducing device is adsorbed onto the substrate, and after exhausting non-adsorbed gas, laser pulse light is emitted from the optical guide a. There are many.

Further, according to the present invention, the optical excitation process apparatus is provided with a window cleaning gas supply device that sprays a window cleaning gas onto the light introduction window of the light introduction device, so that the reaction gas introduced to the substrate in the reaction chamber and the light introduced into the reaction chamber are provided. The light irradiation is performed before the window cleaning gas is mixed with the window cleaning gas that is blown onto the window.

Effect: With this configuration, in the apparatus according to the present invention, the supply of the reaction gas is controlled in synchronization with the laser pulse, so the flow rate of the reaction gas can be reduced.
Reactant gas savings and pump load reduction are achieved.

By lowering the pressure inside the reaction chamber by exhausting gas when the reaction gas is stopped, the state of film formation can be monitored in-process using RHEED or a surface analyzer.

In addition, by adsorbing the reaction gas onto the substrate and irradiating the laser pulse after exhausting the unadsorbed gas, the reaction can be restricted to the surface of the substrate, thereby avoiding the deposition of fine particles generated in the gas phase. be able to.

Furthermore, by performing light irradiation while changing the type of reactant gas for each laser pulse or for each laser pulse, a film having a rapid change in composition can be formed.

Furthermore, the light transmittance can be maintained at a predetermined level by spraying window cleaning gas onto the light introduction window to prevent film formation on the light introduction window.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to page 1 of the appendix.

FIG. 1 schematically shows the configuration of an apparatus according to an embodiment of the present invention, in which 1 is a reaction chamber, which can be evacuated via an exhaust boat 2. As shown in the figure, a substrate holder 4 for holding a substrate 5 is disposed in the reaction chamber 1, and a laser beam from a laser light source 5 is introduced into the substrate 3 to be processed inside the reaction chamber 1. A light introduction window 6 is provided.

Reference numerals 7 and 8.9 shown in the reaction chamber 1 are pulse injection valves such as a solenoid, piezo element, rotary slit, etc. that can be turned on and off at a speed of 1 u, respectively.
is connected to different reactant gas sources (not shown) via reactant gas Hirojin'fF 10, 11, and valve 9Fi.
It is connected via an inlet pipe 12 to a clean gas source (not shown), the valve 9 of which is directed towards the light introduction window 6, and the -10,000 reaction gas pulse injection valve 7.8 directed towards the substrate 6. Further, numerals 13 and 14 are in-process monitors for monitoring the state of reaction processing (for example, film formation) on the substrate 5, and numeral 15 is a heater. Although not shown, the substrate holder 4 is configured to allow temperature control.

The laser light source 5 and each injection valve 7.8.9 are connected to a control device, represented by block 16. Control device 16
synchronously controls the irradiation of laser pulses from the laser light source 5 and the operation of each injection valve.

The operation of the apparatus configured as described above will be explained with reference to FIG.

Operation example 1 As shown in FIG. 2(a), when either one of the reaction gas pulse injection valves 7.8 is turned on by the control device 16 and the pressure inside the reaction chamber 1 increases due to the introduction of the reaction gas, the laser, 2 lus is irradiated through the light introduction window 6. Then the pulse injection valve 7 or 8 is turned off,
The non-reacting gas in the reaction chamber 1 is exhausted, and thus the reaction chamber 1
In-process monitor 15.1
4, the surface condition of the substrate 50 is analyzed.

By shortening the pulse injection valve on time (ie, lj+1 release time), the flow rate of the reactant gas can be reduced. For example, if the valve opening time is set to 1 millisecond and the valve is opened and closed 10 times per second, the reactant gas will be much faster compared to the conventional continuous flow. . becomes. It is also assumed that the pressure inside the reaction chamber 1 becomes 10' Pa when the valve is opened. 10 reaction chambers and 10 groups! When the pumping speed is 1 onol/s, the pressure inside the reaction chamber 1 becomes 10 Pa after 4 seconds. Therefore, in this total, in example q, when the pulp is opened and closed 10 times per second, the minimum pressure will be 1 U-3 Pa, and the surface analysis can be performed at that point.

As shown in Figure 2 (b), the reaction gas pulse fl
? Open the $I valve 7 or 8 and the clean gas pulse injection valve 9 to admit the reaction gas and the clean gas,
Laser pulse δ is applied before both gases mix.

Operation example 3゜ As shown in Fig. 2 (c) K, open the valve 7 or 8 to eject the reaction gas and adsorb it onto the surface of the substrate 3. After exhausting the unadsorbed gas, the reaction chamber is After the pressure inside 1 has decreased to a predetermined level, a laser pulse is irradiated to cause the adsorbed gas to react.

Operation example 4゜As shown in Fig. 2 (d), the valve 7.8 is opened alternately for every laser pulse (also several Vi).
11 By changing the type of gas emitted, a film with a steep compositional change is formed.

In addition, in the operation of the apparatus shown in FIG. 1, by activating the heater 15 to heat the light introduction window 6, adsorption of the reaction gas on the window 6 is prevented, thereby effectively avoiding film formation on the window surface. be able to.

In this way, in this device 1-, each pulse injection valve 7 to 9 is controlled on and off in synchronization with the repetition of laser pulses, and the opening time of each valve and the back pressure of the valve are adjusted. Control the gas flow ht and flow condition.

Effects As explained above, according to the present invention, the following effects can be obtained.

11) By setting the on-time of each injection valve to be short, the flow rate of the reactant gas can be reduced, reducing the reactant gas hi, reducing the pump load, and preventing corrosion caused by the reactant gas (especially in the case of photo-etching). Burning down is 1! t be beaten.

(2) Efficient photochemical reactions can be carried out by light irradiation and reaction gas conversion.

1; () In-process monitoring can be performed by lowering the pressure in the reaction chamber when the valve is closed.

・1; By controlling the laser source only for the gas that has arrived on the surface of Fukusei, it is possible to prevent particle generation in the atmosphere and improve the one-time efficiency.

+51 The light ζ can be prevented from forming a film by the reactive gas in the large window, and the light transmittance can be maintained at the desired level.

・61 It is possible to form a film with a sudden change in composition by changing the amount of reactive gas used each time a laser pulse is irradiated.

i71 By reducing the flow rate of the reaction gas, the amount of exhaust gas processed can be reduced, and the operating cost of the device can be significantly reduced.

11'i Table of Contents Figure 1 shows an apparatus according to an embodiment of the present invention. ,
'tV6 and 432 are operation explanatory diagrams.

In the figure, 1: reaction chamber, 3: substrate, 5: laser light source,
6: Light introduction window, 7-9: Bulb.

13.14: In-process monitor, 16: Control device F
(.

Figure 2: Ray or one pulse
−−−−−−−−−, N−−1111111 force f
f'-y,)t,x

Claims (1)

[Claims] 1. A reaction gas introduction device that introduces a reaction gas into a reaction chamber, and a light introduction device that irradiates the reaction gas introduced into the reaction chamber with laser pulse light to cause a photochemical reaction. ,
A photoexcitation process device characterized in that the introduction of a reaction gas into a reaction chamber and the irradiation of light are performed with a certain time relationship. 2. A plurality of reaction gas introduction devices are provided to introduce different reaction gases into the reaction chamber, and a different reaction gas is introduced from the different reaction gas introduction devices each time one or several laser pulses are irradiated from the light introduction device. 2. The apparatus according to claim 1, wherein a reactive gas is introduced. 3. The reactive gas introduced from the reactive gas introducing device is adsorbed onto the substrate, and after the non-adsorbed gas is exhausted, laser pulse light is irradiated from the light introducing device.
Equipment described in Section. 4. A reaction gas introduction device that introduces a reaction gas into the reaction chamber, a light introduction device that irradiates the reaction gas introduced into the reaction chamber with laser pulse light to cause a photochemical reaction, and a light introduction window of the light introduction device. and a window cleaning gas supply device that sprays window cleaning gas onto the substrate, and performs light irradiation before the reaction gas introduced into the substrate in the reaction chamber and the window cleaning gas blown onto the light introducing window in the reaction chamber mix. A photoexcitation process device characterized by: