JP2005045158A - Vapor-phase film-forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film-forming apparatus which forms a film of high reproducibility by preventing growth of the film under an unstable condition at an initial stage of gas introduction and furthermore by eliminating the instability of the gas flow rate by always monitoring the gas flow rate during the film growth. <P>SOLUTION: The film-forming apparatus is provided with a mass flow controller 204, a gas flowmeter 501a installed in parallel to a reaction chamber 202, a gas flowmeter 501b installed in series with the reaction chamber 202, and a CPU 502 for controlling the film-forming apparatus. The mass flow controller and the flowmeters are connected to the CPU 502 with signal wires. The CPU 502 controls the mass flow controller 204 in such a way that the measured values measured by the gas flowmeters are equal to a set value to always maintain a stable gas flow rate. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for vapor phase growth of various films by heat treatment in the manufacture of a semiconductor using a wafer substrate or the manufacture of a liquid crystal panel using a glass substrate.

  Some conventional film forming apparatuses have a mechanism for constantly monitoring the concentration of the reactive gas in the chamber. FIG. 7 is a diagram for explaining a conventional film forming apparatus described in the following patent document. Here, a single wafer deposition apparatus will be described.

  1 is a mass flow controller, 2 is a carrier gas pipe, 3 is a reactive gas pipe, 4 is a chamber, 5 is a wafer, 8 is a heating lamp, 9 is an exhaust pipe, 11 is a suction pump, 14 is a bypass, 21 is a flow control valve It is.

  A semiconductor manufacturing apparatus that performs thin film formation, impurity diffusion, and the like by heating a semiconductor substrate in the chamber and flowing a carrier gas and a reactive gas is equipped with a mechanism that constantly monitors the concentration of the reactive gas in the chamber. Reproducibility is improved by performing the process after the reaction gas concentration in the chamber becomes equal to the gas flow rate controlled by the mass flow controller.

The above-mentioned mechanism for monitoring the concentration of the reaction gas is a method for detecting the current accompanying the electrolysis of the reaction gas (constant potential electrolysis method), or a method for detecting the current accompanying the oxidation-reduction reaction of the reaction gas that has passed through the diaphragm (galvanic cell). Law).
Japanese Patent Laid-Open No. 09-27456

  However, in the conventional configuration, the gas concentration during film formation is analyzed, and the film formation is performed after the gas flow rate ratio becomes equal. However, in the case of this method, the analysis takes time and the responsiveness deteriorates. . In addition, during the film formation, the gas after the thermal reaction is analyzed, and the gas flow rate during supply cannot be accurately measured.

  The present invention solves the above-described conventional problems, eliminates film formation in an unstable state at the beginning of gas introduction, and further eliminates instability of flow rate by constantly monitoring the gas flow rate during film formation, An object of the present invention is to provide an apparatus that realizes film formation with high reproducibility.

  In order to solve the above-described conventional problems, the vapor phase film forming apparatus of the present invention is provided with a gas flow meter represented by a preliminary chamber or a mass flow meter in front of a reaction chamber in which a film is actually formed. Before introducing the gas into the reaction chamber and depositing the film on the wafer, the gas is introduced into the preliminary chamber to adjust and confirm the gas flow rate. Defects due to can be avoided.

  Further, even during film formation, when the value measured by the gas flow meter is different from the set value, the mass flow controller can be fed back so as to obtain a normal flow rate.

  As described above, in the present invention, variations in film thickness and film quality of a film forming apparatus in the manufacture of a semiconductor device can be suppressed, and growth of a film with good reproducibility can be expected. It is possible to supply a stable film at the start of film formation in order to form a film on a wafer substrate after the gas flow rate is stabilized by a preliminary chamber or a gas flow meter before film formation in the reaction chamber. In addition, a stable film can be continuously supplied by constantly monitoring and adjusting the gas flow rate during film formation. Furthermore, failure diagnosis of the apparatus can also be performed.

  In the case of a batch type apparatus, if a defect occurs in film thickness or film quality due to a defect such as a gas flow rate, a wafer of several hundred wafers becomes defective at a time. In addition, along with the recent increase in diameter, even a single-wafer type device has a large amount of damage for a single defective. The present invention can minimize the above-mentioned problems and improve the product yield and quality of semiconductor device manufacturing.

(Embodiment 1)
FIG. 1 is a schematic diagram of a vapor deposition apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, 201 is a wafer substrate, 202 is a reaction chamber, 203 is a heater, 204 is a mass flow controller, 205 and 206 are valves used for a gas introduction system, 207 is a spare chamber, and 208 and 209 are valves used for an exhaust system. 210 are heaters for heating the spare chamber.

  First, the basic operation will be described. The wafer substrate 201 is transferred to the reaction chamber 202 using a transfer system or the like (not shown), and placed in a predetermined boat or the like (not shown). The reaction chamber 202 is heated to a predetermined temperature by the heater 203, and the wafer substrate 201 is similarly heated. Thereafter, a plurality of gases controlled to a predetermined gas flow rate by a plurality of mass flow controllers 204 are introduced into the reaction chamber 202 and deposited on the wafer substrate 201.

  Hereinafter, the operation of the present invention will be described in detail. At the beginning of gas introduction, the valves 206 and 209 are closed, the valves 205 and 208 are opened, and the gas flows into the auxiliary chamber 207. The gas introduction part of the preliminary chamber 207 has the same opening as the introduction part of the reaction chamber 202. Further, the heater 210 is heated to the same temperature as the reaction chamber 202. The shape of the gas introduction part of the preliminary chamber 207 is made the same assuming that the diameter is actually wide from the thin gas pipe and introduced into the high temperature reaction chamber. However, the internal volume is reduced in order to confirm the stabilization of the gas flow rate at an early stage. After flowing the gas into the preliminary chamber 207 until the predetermined flow rate is reached, after confirming the stability for about 5 seconds, the valves 208 and 205 are closed, the valves 206 and 209 are opened, and the gas is allowed to flow into the reaction chamber 202. Then, a film is formed on the wafer substrate 201. Since the deposition film gradually grows on the inner wall of the preliminary chamber 207, the deposition gas is removed by flowing a cleaning gas during the processing of the wafer substrate 201 in the reaction chamber 202.

(Embodiment 2)
FIG. 2 is a schematic view of a vapor deposition apparatus according to Embodiment 2 of the present invention.

  In FIG. 2, the same components as those in FIG.

  In FIG. 2, 301 is a gas flow meter represented by a mass flow meter. In this embodiment mode, a gas flow meter 301 is installed in parallel with the reaction chamber 202. At the beginning of gas introduction, the valves 206 and 209 are closed, the valves 205 and 208 are opened, and the gas flows through the gas flow meter 301. After confirming that the set value of the mass flow controller 204 matches the measured value of the gas flow meter 301, the valves 208 and 205 are closed, the valves 206 and 209 are opened, and the gas is allowed to flow into the reaction chamber 202. A film is formed on 201. In the case of this embodiment, the same number of gas flow meters 301 as the mass flow controller are required. Similarly, the valves 205, 206, 208, and 209 need to be installed in the same number.

  According to the first and second embodiments, variations in film quality and film thickness due to unstable gas flow at the beginning of gas introduction can be suppressed, and processing defects in the film forming process can be reduced.

(Embodiment 3)
FIG. 3 is a schematic diagram of a vapor deposition apparatus according to Embodiment 3 of the present invention.

  In FIG. 3, the same components as those in FIGS.

  In FIG. 3, the gas flow meter 401 is installed in series before the reaction chamber 202. The valve 402 is installed between the reaction chamber 202 and the gas flow meter 401. The mass flow controller 204 is activated and the valve 402 is opened. During normal operation, the mass flow controller 204 and the gas flow meter 401 display the same value. However, due to an abnormality in the mass flow controller 204 during film formation, clogging of piping, gas liquefaction, etc., the gas flow rate fluctuates despite the mass flow controller 204 being normal, resulting in variations in film thickness and film quality. Sometimes. In this case, by leaving both values as logs, the response to product and equipment abnormalities is accelerated.

(Embodiment 4)
FIG. 4 is a schematic diagram of a vapor deposition apparatus according to Embodiment 4 of the present invention.

  In FIG. 4, the same reference numerals are used for the same components as those in the previous figure, and the description thereof is omitted.

  In FIG. 4, the gas flow meter 501 a is installed in parallel with the reaction chamber 202, and the gas flow meter 501 b is installed in series. In FIG. 4, the gas is shown as one system, but there may be a plurality of gases. The operation will be described below. At the beginning of gas introduction, the valves 206 and 209 are closed, the valves 205 and 208 are opened, and the gas flows through the gas flow meter 501a. After confirming that the set value of the mass flow controller 204 matches the measured value of the gas flow meter 501a, the valves 208 and 205 are closed, the valves 206 and 209 are opened, and the gas is allowed to flow into the reaction chamber 202, whereby the wafer substrate A film is formed on 201. Next, during film formation, the gas flowmeter 501b is used to confirm the stability of the gas flow rate during film formation.

(Embodiment 5)
FIG. 5 is a schematic diagram of a vapor deposition apparatus according to Embodiment 5 of the present invention.

  In FIG. 5, 502 is a CPU for controlling the film forming apparatus of the present invention, 503 is a signal line for connecting the gas flow meter installed in series with the reaction chamber and the CPU, 504 is a signal line for connecting the mass flow controller and the CPU, 505 Is a signal line for connecting the gas flow meter installed in parallel with the reaction chamber and the CPU. In FIG. 5, the gas is shown as one system, but there may be a plurality of gases.

  FIG. 6 is a flowchart for explaining the operation of the present invention. The same components as those in the previous figure are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 5, the configuration of the gas flow is the same as that of the fourth embodiment. At the beginning of the gas introduction, the gas whose gas flow rate is adjusted by the mass flow controller 204 is opened by the valves 205 and 208, the flow rate is confirmed by the gas flow meter 501a, and the measured value is transmitted to the CPU 502 via the signal line 505. If it is within ± 5% of the set value in the CPU 502 (this set value is arbitrarily set by the apparatus and process), the valves 205 and 208 are closed, the valves 206 and 209 are opened, and the gas is allowed to flow into the reaction chamber 202. To start film formation. If it is not within the setting, a signal is sent to the mass flow controller 204 to make adjustment again. Even if this operation is repeated three times, if it is NG, the CPU 502 generates an NG signal. Then stop the device and check the mass flow controller, or send the signal to the mass flow controller 204 via the signal line 504 with the device as it is, and the flow rate so that the gas flow meter 501a satisfies the initial set value ± standard. To reset. Similarly, the apparatus stops in the case of NG even if it is repeated three times.

  Next, during film formation, the gas flow meter 501b measures the flow rate and sends a signal to the CPU 502 via the signal line 503 to confirm that it is within ± 5% of the set value. This check is performed at regular intervals, and when there is an abnormality three times (optionally settable), an abnormality signal is sent to the CPU 502 and an instruction to reset the mass flow controller 204 is given via the signal line 504. The film formation is continued while repeating the above operation.

  The preliminary chambers or gas flowmeters described in the first to fifth embodiments are provided with a mechanism for allowing a cleaning gas to flow, so that measurement in a stable state is always possible.

  Although the batch type film forming apparatus has been described in the above description, the same applies to a single wafer type film forming apparatus.

  The vapor deposition apparatus of the present invention is useful for suppressing film thickness and film quality variations of a deposition apparatus in the manufacture of a semiconductor device and growing a film with good reproducibility.

Schematic diagram of a vapor deposition apparatus in Embodiment 1 of the present invention Schematic diagram of a vapor deposition apparatus in Embodiment 2 of the present invention Schematic diagram of vapor deposition apparatus in Embodiment 3 of the present invention Schematic diagram of vapor deposition apparatus in Embodiment 4 of the present invention Schematic diagram of a vapor deposition apparatus in Embodiment 5 of the present invention Flowchart for explaining the operation of the vapor deposition apparatus according to Embodiment 5 of the present invention. Explanatory drawing of conventional film forming equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mass flow controller 2 Carrier gas piping 3 Reactive gas piping 4 Chamber 5 Wafer 8 Heating lamp 9 Exhaust piping 11 Suction pump 14 Bypass 21 Flow control valve 201 Wafer substrate 202 Reaction chamber 203 Heater 204 Mass flow controller 205, 206 Used for gas introduction system Valve 207 Preliminary chamber 208, 209 Valve used for exhaust system 210 Heater for heating preparatory chamber 301 Gas flow meter 401 Gas flow meter 402 Valve 501a Gas flow meter 501b Gas flow meter 502 CPU for controlling film forming apparatus
503 Signal line connecting CPU with gas flow meter installed in parallel with reaction chamber 504 Signal line connecting CPU with mass flow controller and CPU 505 Signal line connecting CPU with gas flow meter installed in series with reaction chamber

Claims (5)

A reaction chamber for forming a predetermined film thickness using a reactive gas on a substrate; a mass flow for adjusting a gas flow rate; a spare chamber provided in parallel between the reaction chambers; and the spare chamber And a valve for controlling a gas flow installed between the reaction chamber and the reaction chamber. The vapor deposition apparatus according to claim 1, wherein the opening shape, opening area, temperature, and pressure of the preliminary chamber are the same as those of the reaction chamber. A reaction chamber for forming a predetermined film thickness on a substrate using a reactive gas, a mass flow for adjusting a gas flow rate, a gas flow meter provided in parallel between the reaction chamber, and the gas A batch type vapor phase film forming apparatus provided with a valve for controlling a gas flow installed between a flow meter and the reaction chamber. A reaction chamber for forming a predetermined film thickness on a substrate using a reactive gas, a mass flow for adjusting a gas flow rate, a gas flow meter provided in series between the reaction chamber, and the gas A batch type vapor phase film forming apparatus provided with a valve for controlling a gas flow installed between a flow meter and the reaction chamber. 2. The vapor phase film formation according to claim 1, further comprising: a reaction chamber; a preliminary chamber provided in parallel; or the gas flow meter provided in parallel; and another gas flow meter provided in series with the reaction chamber. apparatus.

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