JP2011060936A - Method of manufacturing semiconductor device, and substrate processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve productivity by shortening a period of time of exhausting a material gas and an oxidizer from a processing chamber. <P>SOLUTION: The method of manufacturing the semiconductor device includes repeating a plurality of times one cycle comprising the processes of: exhausting the processing chamber while supplying the material gas into the processing chamber in a state wherein exhaust conductance in the processing chamber containing a substrate is set to be first exhaust conductance; purging the processing chamber by exhausting the processing chamber while supplying the purge gas into the processing chamber in a state the exhaust conductance in the processing chamber is set to be second exhaust conductance larger than the first exhaust conductance; exhausting the processing chamber while supplying the oxidizer into the processing chamber in a state wherein the exhaust conductance in the processing chamber is set to be the first exhaust conductance; and purging the processing chamber by exhausting the processing chamber while supplying the purge gas into the processing chamber in a state wherein the exhaust conductance in the processing chamber is set to be the second exhaust conductance. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a semiconductor device having a step of processing a substrate and a substrate processing apparatus suitably used in the step.

  As one process of manufacturing a semiconductor device (device), there is a film forming process for forming a thin film such as a high dielectric constant insulating film on a substrate by an ALD (Atomic Layer Deposition) method. There is also a film forming process for forming a thin film such as a high dielectric constant insulating film cyclically by a CVD (Chemical Vapor Deposition) method (hereinafter also referred to as a cyclic CVD method).

  In these film forming steps, a source gas is usually supplied into a processing chamber containing a substrate, a source gas is discharged from the processing chamber, an oxidant is supplied into the processing chamber, and an oxidation is performed from the processing chamber. The step of discharging the agent is defined as one cycle, and this cycle is repeated a plurality of times (see, for example, Patent Document 1 and Patent Document 2).

WO2005 / 071723 JP 2004-158811 A

  However, some source gases and oxidizers are easily adsorbed by members in the processing chamber and are difficult to desorb. When these source gases and oxidizers are used, it takes time to discharge the source gas and oxidizer from the processing chamber. This may lead to a decrease in productivity.

  An object of the present invention is to provide a method of manufacturing a semiconductor device and a substrate processing apparatus that can shorten the discharge time of the source gas and oxidant from the processing chamber and improve the productivity.

According to one aspect of the invention,
Evacuating the processing chamber while supplying a source gas into the processing chamber in a state where the exhaust conductance in the processing chamber containing the substrate is the first exhaust conductance;
Purging the processing chamber by exhausting the processing chamber while supplying a purge gas to the processing chamber in a state where the exhaust conductance in the processing chamber is set to a second exhaust conductance larger than the first exhaust conductance. When,
Evacuating the processing chamber while supplying the oxidant into the processing chamber with the exhaust conductance in the processing chamber being the first exhaust conductance;
Purging the processing chamber by exhausting the processing chamber while supplying a purge gas to the processing chamber in a state where the exhaust conductance in the processing chamber is the second exhaust conductance;
As a cycle, a method for manufacturing a semiconductor device is provided in which this cycle is repeated a plurality of times.

According to another aspect of the invention,
A processing chamber for processing the substrate;
A raw material gas supply system for supplying a raw material gas into the processing chamber;
An oxidizing agent supply system for supplying an oxidizing agent into the processing chamber;
A purge gas supply system for supplying a purge gas into the processing chamber;
An exhaust system for exhausting the processing chamber;
An exhaust conductance adjusting unit for adjusting the exhaust conductance in the processing chamber;
With the exhaust conductance in the processing chamber set to the first exhaust conductance, the processing chamber is exhausted while supplying the source gas into the processing chamber, and the exhaust conductance in the processing chamber is set to be higher than the first exhaust conductance. In a state where the second exhaust conductance is large, the process chamber is purged by exhausting the process chamber while supplying a purge gas into the process chamber, and the exhaust conductance in the process chamber is set as the first exhaust conductance. In the state, the processing chamber is exhausted while supplying the oxidizing agent into the processing chamber, and the exhaust gas conductance in the processing chamber is set to the second exhaust conductance, and the processing gas is supplied while purging gas is supplied into the processing chamber. The processing chamber is purged by exhausting the chamber, and this is defined as one cycle. As repeated a plurality of times, and the raw material gas supply system, the oxidant supply system, the purge gas supply system, the exhaust system, and a control unit for controlling the exhaust conductance adjustment unit,
A substrate processing apparatus is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a semiconductor device and substrate processing apparatus which can shorten the discharge | emission time of the source gas and oxidizing agent from a process chamber, and can improve productivity can be provided.

1 is a layout diagram showing a gas supply system of a substrate processing apparatus according to an embodiment of the present invention. It is a sequence diagram as a timing chart which shows the timing of source gas supply concerning the embodiment of the present invention, ozone gas supply, support stand position change, and exhaust conductance change. It is a section lineblock diagram at the time of wafer processing of a substrate processing device concerning one embodiment of the present invention. It is a section lineblock diagram at the time of wafer conveyance of a substrate processing device concerning one embodiment of the present invention. It is a flowchart which shows the method of processing the board | substrate concerning one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First, the configuration of the substrate processing apparatus according to the present embodiment will be described with reference to FIGS. FIG. 3 is a cross-sectional configuration diagram of the substrate processing apparatus according to the embodiment of the present invention during wafer processing, and FIG. 4 is a cross-sectional configuration diagram of the substrate processing apparatus according to the embodiment of the present invention during wafer transfer.

<Processing chamber>
As shown in FIGS. 3 and 4, the substrate processing apparatus according to this embodiment includes a processing container 202. The processing container 202 is configured as a flat sealed container having a circular cross section, for example. Moreover, the processing container 202 is comprised, for example with metal materials, such as aluminum (Al) and stainless steel (SUS). A processing chamber 201 for processing a wafer 200 as a substrate is formed in the processing container 202.

A support table 203 that supports the wafer 200 is provided in the processing chamber 201. For example, quartz (SiO ₂ ), carbon, ceramics, silicon carbide (SiC), aluminum oxide (Al ₂ O ₃ ), or aluminum nitride (AlN) is formed on the upper surface of the support base 203 that the wafer 200 directly touches. A susceptor 217 is provided as a support plate. In addition, the support base 203 incorporates a heater 206 as a heating means for heating the wafer 200. Note that the lower end portion of the support base 203 passes through the bottom portion of the processing container 202.

  Outside the processing chamber 201, an elevating mechanism 207b for elevating the support base 203 is provided. The wafer 200 supported on the susceptor 217 can be moved up and down by operating the lifting mechanism 207 b to raise and lower the support base 203. The support table 203 is lowered to the position shown in FIG. 4 (wafer transfer position) when the wafer 200 is transferred, and is raised to the position shown in FIG. 3 (wafer processing position) when the wafer 200 is processed. Note that the periphery of the lower end portion of the support base 203 is covered with a bellows 203a, and the inside of the processing chamber 201 is kept airtight.

  In addition, on the bottom surface (floor surface) of the processing chamber 201, for example, three lift pins 208b are provided so as to rise in the vertical direction. Further, the support base 203 (including the susceptor 217) is provided with through holes 208a through which the lift pins 208b pass, at positions corresponding to the lift pins 208b. When the support table 203 is lowered to the wafer transfer position, as shown in FIG. 4, the upper end portion of the lift pins 208b protrudes from the upper surface of the susceptor 217, and the lift pins 208b support the wafer 200 from below. Yes. When the support table 203 is raised to the wafer processing position, as shown in FIG. 3, the lift pins 208b are buried from the upper surface of the susceptor 217 so that the susceptor 217 supports the wafer 200 from below. In addition, since the lift pins 208b are in direct contact with the wafer 200, it is desirable to form the lift pins 208b with a material such as quartz or alumina.

<Wafer transfer port>
On the inner wall side surface of the processing chamber 201 (processing container 202), a wafer transfer port 250 for transferring the wafer 200 into and out of the processing chamber 201 is provided. The wafer transfer port 250 is provided with a gate valve 251. By opening the gate valve 251, the processing chamber 201 and the transfer chamber (preliminary chamber) 271 communicate with each other. The transfer chamber 271 is formed in a transfer container (sealed container) 272, and a transfer robot 273 that transfers the wafer 200 is provided in the transfer chamber 271. The transfer robot 273 includes a transfer arm 273 a that supports the wafer 200 when the wafer 200 is transferred. By opening the gate valve 251 while the support table 203 is lowered to the wafer transfer position, the transfer robot 273 can transfer the wafer 200 between the processing chamber 201 and the transfer chamber 271. Yes. The wafer 200 transferred into the processing chamber 201 is temporarily placed on the lift pins 208b as described above. Note that a load lock chamber (load lock module) (not shown) is provided on the opposite side of the transfer chamber 271 from the side where the wafer transfer port 250 is provided, and the transfer robot 273 allows the load lock chamber and the transfer chamber 271 to be connected. The wafer 200 can be transferred between the two. The load lock chamber functions as a spare chamber for temporarily storing unprocessed or processed wafers 200.

<Exhaust system>
An exhaust port 260 for exhausting the atmosphere in the processing chamber 201 is provided on the inner wall side surface of the processing chamber 201 (processing container 202) on the opposite side of the wafer transfer port 250. An exhaust pipe 261 is connected to the exhaust port 260 via an exhaust chamber 260a. The exhaust pipe 261 has a pressure regulator 262 such as an APC (Auto Pressure Controller) for controlling the inside of the processing chamber 201 at a predetermined pressure, A raw material recovery trap 263 and a vacuum pump 264 are connected in series in this order.
An exhaust system (exhaust line) is mainly configured by the exhaust port 260, the exhaust chamber 260a, the exhaust pipe 261, the pressure regulator 262, the raw material recovery trap 263, and the vacuum pump 264.

<Gas inlet>
A gas inlet 210 for supplying various gases into the processing chamber 201 is provided on the upper surface (ceiling wall) of a shower head 240 described later provided in the upper portion of the processing chamber 201. The configuration of the gas supply system connected to the gas inlet 210 will be described later.

<Shower head>
A shower head 240 as a gas dispersion mechanism is provided between the gas inlet 210 and the wafer 200 at the wafer processing position. The shower head 240 disperses the gas introduced from the gas introduction port 210 and the gas that has passed through the dispersion plate 240 a are more uniformly dispersed and supplied to the surface of the wafer 200 on the support table 203. A shower plate 240b. The dispersion plate 240a and the shower plate 240b are provided with a plurality of vent holes. The dispersion plate 240 a is disposed so as to face the upper surface of the shower head 240 and the shower plate 240 b, and the shower plate 240 b is disposed so as to face the wafer 200 on the support table 203. Note that spaces are provided between the upper surface of the shower head 240 and the dispersion plate 240a, and between the dispersion plate 240a and the shower plate 240b, respectively, and the spaces are supplied from the gas inlet 210. Function as a first buffer space (dispersion chamber) 240c for dispersing the gas and a second buffer space 240d for diffusing the gas that has passed through the dispersion plate 240a.

<Exhaust duct>
On the inner wall side surface of the processing chamber 201, a step portion 201a is provided. The step portion 201a is configured to hold the conductance plate 204 in the vicinity of the wafer processing position. The conductance plate 204 is configured as a single donut-shaped (ring-shaped) disk in which a hole for accommodating the wafer 200 is provided in the inner periphery. A plurality of discharge ports 204 a arranged in the circumferential direction with a predetermined interval are provided on the outer periphery of the conductance plate 204. The discharge port 204 a is formed discontinuously so that the outer periphery of the conductance plate 204 can support the inner periphery of the conductance plate 204.

  On the other hand, a lower plate 205 is locked to the outer peripheral portion of the support base 203. The lower plate 205 includes a ring-shaped concave portion 205b and a flange portion 205a provided integrally on the inner upper portion of the concave portion 205b. The recess 205 b is provided so as to close a gap between the outer peripheral portion of the support base 203 and the inner wall side surface of the processing chamber 201. A part of the bottom of the recess 205b near the exhaust port 260 is provided with a plate exhaust port 205c for discharging (circulating) gas from the recess 205b to the exhaust port 260 side. The flange portion 205 a functions as a locking portion that locks on the upper outer periphery of the support base 203. When the flange portion 205 a is locked on the upper outer periphery of the support base 203, the lower plate 205 is moved up and down together with the support base 203 as the support base 203 is moved up and down.

  When the support table 203 is raised to the wafer processing position, the lower plate 205 is also raised to the wafer processing position. As a result, the conductance plate 204 held in the vicinity of the wafer processing position closes the upper surface portion of the recess 205b of the lower plate 205, and the exhaust duct 259 having the gas passage region inside the recess 205b is formed. . At this time, due to the exhaust duct 259 (conductance plate 204 and lower plate 205) and the support base 203, the inside of the processing chamber 201 is located above the processing chamber above the exhaust duct 259, and below the processing chamber below the exhaust duct 259. , Will be partitioned. The conductance plate 204 and the lower plate 205 are made of materials that can be kept at a high temperature, for example, high temperature and high load resistance, in consideration of etching reaction products deposited on the inner wall of the exhaust duct 259 (self cleaning). Preferably, it is made of quartz for use.

  Here, the flow of gas in the processing chamber 201 during wafer processing will be described. First, the gas supplied from the gas inlet 210 to the upper portion of the shower head 240 enters the second buffer space 240d through the first buffer space (dispersion chamber) 240c through a large number of holes in the dispersion plate 240a, and further into the shower. It passes through a large number of holes in the plate 240 b and is supplied into the processing chamber 201, and is uniformly supplied onto the wafer 200. The gas supplied onto the wafer 200 flows radially outward of the wafer 200 in the radial direction. The surplus gas after contacting the wafer 200 flows radially on the exhaust duct 259 located on the outer peripheral portion of the wafer 200, that is, on the conductance plate 204, radially outward of the wafer 200. Is discharged into the gas flow path region (in the recess 205b) in the exhaust duct 259. Thereafter, the gas flows through the exhaust duct 259 and is exhausted to the exhaust port 260 via the plate exhaust port 205c. By flowing the gas in this way, gas wraparound to the lower portion of the processing chamber 201, that is, the back surface of the support base 203 and the bottom surface side of the processing chamber 201 is suppressed.

  Note that it is also possible to flow gas into the processing chamber 201 with the support table 203 lowered during wafer processing. In this case, the gas is supplied onto the wafer 200 in a state where the conductance plate 204 and the lower plate 205 are separated from each other and the upper surface portion of the recess 205b of the lower plate 205 is opened. The gas supplied onto the wafer 200 flows radially outward in the radial direction of the wafer 200, and on the flange portion 205 a of the lower plate 205 located on the outer peripheral portion of the wafer 200, outward in the radial direction of the wafer 200. It flows radially and is discharged into the recess 205b. Thereafter, the gas flows through the recess 205b and is exhausted to the exhaust port 260 via the plate exhaust port 205c.

In this case, the exhaust conductance in the processing chamber is larger than the exhaust conductance in the processing chamber when the support base 203 is raised to the wafer processing position. That is, the exhaust conductance in the processing chamber can be adjusted (set) to a desired exhaust conductance by raising and lowering the support base 203. Here, the exhaust conductance in the processing chamber when the support base 203 is raised to the wafer processing position is defined as a first exhaust conductance, and the processing when the support base 203 is at an intermediate position between the wafer processing position and the wafer transfer position. The exhaust conductance in the chamber is the second exhaust conductance, and the exhaust conductance in the processing chamber when the support base 203 is lowered to the wafer transfer position is the third exhaust conductance. In this case, the second exhaust conductance is larger than the first exhaust conductance, and the third exhaust conductance is larger than the second exhaust conductance.
The conductance plate 204, the lower plate 205, the support base 203, and the elevating mechanism 207b mainly constitute an exhaust conductance adjustment (setting) unit.

  Next, the configuration of the gas supply system connected to the gas inlet 210 described above will be described with reference to FIG. FIG. 1 is a configuration diagram of a gas supply system (gas supply line) included in a substrate processing apparatus according to an embodiment of the present invention.

<Liquid material supply system>
Outside the processing chamber 201, a first liquid source supply source 220h for supplying an organometallic liquid source (hereinafter also referred to as Hf source) containing Hf (hafnium) as a first liquid source, and a second liquid source as a second liquid source A second liquid source supply source 220s that supplies an organometallic liquid source containing Si (silicon) (hereinafter also referred to as Si source) is provided. The first liquid raw material supply source 220h and the second liquid raw material supply source 220s are respectively configured as tanks (sealed containers) that can contain (fill) the liquid raw material.

Here, pressure gas supply pipes 237h and 237s are connected to the first liquid source supply source 220h and the second liquid source supply source 220s, respectively. A pressure gas supply source (not shown) is connected to upstream ends of the pressure gas supply pipes 237h and 237s. Further, the downstream end portions of the pressurized gas supply pipes 237h and 237s communicate with spaces existing in the upper portions of the first liquid raw material supply source 220h and the second liquid raw material supply source 220s, respectively. Gas is supplied. As the pressurized gas, it is preferable to use a gas that does not react with the liquid material, for example an inert gas such as N ₂ gas is preferably used.

  A first liquid source supply pipe 211h and a second liquid source supply pipe 211s are connected to the first liquid source supply source 220h and the second liquid source supply source 220s, respectively. Here, the upstream end portions of the first liquid source supply pipe 211h and the second liquid source supply pipe 211s are immersed in the liquid source accommodated in the first liquid source supply source 220h and the second liquid source supply source 220s, respectively. Has been. In addition, the downstream end portions of the first liquid source supply pipe 211h and the second liquid source supply pipe 211s are connected to vaporizers 229h and 229s as vaporizers for vaporizing the liquid source, respectively. The first liquid source supply pipe 211h and the second liquid source supply pipe 211s control liquid flow rate controllers (LMFC) 221h and 221s as flow rate control means for controlling the supply rate of the liquid source, and supply of the liquid source. Opening and closing valves vh1 and vs1 are provided, respectively. The open / close valves vh1 and vs1 are provided inside the vaporizers 229h and 229s, respectively.

In the above configuration, the open / close valves vh1 and vs1 are opened and the pressurized gas is supplied from the pressurized gas supply pipes 237h and 237s, whereby the vaporizers 229h and 229s are supplied from the first liquid source supply source 220h and the second liquid source supply source 220s. The liquid raw material can be pumped (supplied) to the head.
A first liquid source supply system (first liquid source supply line) is mainly configured by the first liquid source supply source 220h, the pressure gas supply pipe 237h, the first liquid source supply pipe 211h, the liquid flow rate controller 221h, and the valve vh1. The second liquid source supply system (second liquid source supply line) is mainly configured by the second liquid source supply source 220s, the pressure gas supply pipe 237s, the second liquid source supply pipe 211s, the liquid flow rate controller 221s, and the valve vs1. Is done.

<Vaporization part>
Vaporizers 229h and 229s serving as vaporizers for vaporizing the liquid raw material are vaporization chambers 20h and 20s that heat the liquid raw material with heaters 23h and 23s to generate a raw material gas, and liquid into the vaporization chambers 20h and 20s. The liquid source channels 21h and 21s, which are channels until the source is discharged, the above-described on-off valves vh1 and vs1 for controlling the supply of the liquid source into the vaporization chambers 20h and 20s, and the vaporization chambers 20h and 20s. There are source gas supply ports 22h and 22s as outlets for supplying the generated source gas to a first source gas supply pipe 213h and a second source gas supply pipe 213s, which will be described later. The downstream end portions of the first liquid raw material supply pipe 211h and the second liquid raw material supply pipe 211s are connected to the upstream end portions of the liquid raw material flow paths 21h and 21s via the open / close valves vh1 and vs1, respectively. . The downstream ends of carrier gas supply pipes 24h and 24s are connected to the liquid source channels 21h and 21s, respectively, and the carrier gas is supplied into the vaporization chambers 20h and 20s through the liquid source channels 21h and 21s. Is configured to do. An N ₂ gas supply source 230c for supplying N ₂ gas as a carrier gas is connected to upstream ends of the carrier gas supply pipes 24h and 24s. Carrier gas supply pipe 24h, the 24s, the flow rate controller (MFC) 225h as a flow rate controller for controlling the supply flow rate of N ₂ gas, and 225s, and the valve vh2, vs2 for controlling the supply of N ₂ gas, respectively Is provided.
A carrier gas supply system (carrier gas supply line) is mainly configured by the N ₂ gas supply source 230c, carrier gas supply pipes 24h and 24s, flow rate controllers 225h and 225s, and valves vh2 and vs2. The vaporizers 229h and 229s are configured as a first vaporizer and a second vaporizer, respectively.

<Raw gas supply system>
The upstream side ends of the first raw material gas supply pipe 213h and the second raw material gas supply pipe 213s for supplying the raw material gas into the processing chamber 201 are respectively connected to the raw material gas supply ports 22h and 22s of the vaporizers 229h and 229s. It is connected. The downstream end portions of the first source gas supply pipe 213h and the second source gas supply pipe 213s are unified so as to merge to become the source gas supply pipe 213, and the unified source gas supply pipe 213 is a gas introduction Connected to the mouth 210. The first source gas supply pipe 213h and the second source gas supply pipe 213s are provided with opening / closing valves vh3 and vs3 for controlling the supply of the source gas into the processing chamber 201, respectively.

In the above configuration, the liquid raw material is vaporized by the vaporizers 229h and 229s to generate the raw material gas, and by opening the on-off valves vh3 and vs3, the first raw material gas supply pipe 213h and the second raw material gas supply pipe 213s The source gas can be supplied into the processing chamber 201 through the source gas supply pipe 213.
A first source gas supply system (first source gas supply line) is mainly configured by the first source gas supply pipe 213h and the valve vh3, and the second source gas supply pipe 213s and the valve vs3 mainly configure the second source gas supply system (first source gas supply line). A source gas supply system (second source gas supply line) is configured. The first liquid source supply system, the first vaporization unit, and the first source gas supply system constitute a first source supply system (Hf source supply system), and the second liquid source supply system, the second vaporization unit, the second source The source gas supply system constitutes a second source supply system (Si source supply system).

<Reactive gas supply system (oxidant supply system)>
In addition, an oxygen gas supply source 230 o that supplies oxygen (O ₂ ) gas is provided outside the processing chamber 201. The upstream end of the first oxygen gas supply pipe 211o is connected to the oxygen gas supply source 230o. The downstream end of the first oxygen gas supply pipe 211o is connected to an ozonizer 229o that generates a reaction gas (reactant), that is, ozone gas as an oxidant, from oxygen gas by plasma. The first oxygen gas supply pipe 211o is provided with a flow rate controller 221o as flow rate control means for controlling the supply flow rate of oxygen gas.

  An upstream end of an ozone gas supply pipe 213o as a reaction gas supply pipe is connected to an ozone gas supply port 22o as an outlet of the ozonizer 229o. The downstream end of the ozone gas supply pipe 213o is connected so as to join the source gas supply pipe 213. That is, the ozone gas supply pipe 213o is configured to supply ozone gas as a reaction gas into the processing chamber 201. The ozone gas supply pipe 213o is provided with an open / close valve vo3 that controls the supply of ozone gas into the processing chamber 201.

  The upstream end of the second oxygen gas supply pipe 212o is connected to the upstream side of the flow rate controller 221o of the first oxygen gas supply pipe 211o. The downstream end of the second oxygen gas supply pipe 212o is connected to the upstream side of the open / close valve vo3 of the ozone gas supply pipe 213o. The second oxygen gas supply pipe 212o is provided with a flow rate controller 222o as flow rate control means for controlling the supply flow rate of oxygen gas.

In the above configuration, oxygen gas is supplied to the ozonizer 229o to generate ozone gas, and ozone gas can be supplied into the processing chamber 201 by opening the opening / closing valve vo3. Note that if the oxygen gas is supplied from the second oxygen gas supply pipe 212o during the supply of the ozone gas into the processing chamber 201, the ozone gas supplied into the processing chamber 201 is diluted with the oxygen gas to obtain an ozone gas concentration. Can be adjusted.
Mainly, a reactive gas supply system (the oxygen gas supply source 230o, the first oxygen gas supply pipe 211o, the ozonizer 229o, the flow controller 221o, the ozone gas supply pipe 213o, the open / close valve vo3, the second oxygen gas supply pipe 212o, and the flow controller 222o) A reaction gas supply line), that is, an oxidant supply system (oxidant supply line).

<Purge gas supply system>
Further, an N ₂ gas supply source 230p for supplying N ₂ gas as a purge gas is provided outside the processing chamber 201. The upstream end of the purge gas supply pipe 214 is connected to the N ₂ gas supply source 230p. The downstream end of the purge gas supply pipe 214 branches into three lines, that is, a first purge gas supply pipe 214h, a second purge gas supply pipe 214s, and a third purge gas supply pipe 214o. The downstream end of the first purge gas supply pipe 214h, the second purge gas supply pipe 214s, and the third purge gas supply pipe 214o is an open / close valve for the first source gas supply pipe 213h, the second source gas supply pipe 213s, and the ozone gas supply pipe 213o. It is connected to the downstream side of vh3, vs3, and vo3, respectively. The first purge gas supply pipe 214h, the second purge gas supply pipe 214s, and the third purge gas supply pipe 214o have flow rate controllers 224h, 224s, and 224o as flow rate control means for controlling the supply flow rate of N ₂ gas, and N _2. Open / close valves vh4, vs4, vo4 for controlling the supply of gas are provided, respectively.
Mainly, N ₂ gas supply source 230p, purge gas supply pipe 214, first purge gas supply pipe 214h, second purge gas supply pipe 214s, third purge gas supply pipe 214o, flow rate controllers 224h, 224s, 224o, open / close valves vh4, vs4 A purge gas supply system (purge gas supply line) is configured by vo4.

<Vent (bypass) system>
Further, on the upstream side of the opening / closing valves vh3, vs3, vo3 of the first source gas supply pipe 213h, the second source gas supply pipe 213s, and the ozone gas supply pipe 213o, the first vent pipe 215h, the second vent pipe 215s, the third The upstream end of the vent pipe 215o is connected to each other. Further, the downstream end portions of the first vent pipe 215h, the second vent pipe 215s, and the third vent pipe 215o are unified so as to join together to form a vent pipe 215, and the vent pipe 215 is a raw material recovery trap 263 of the exhaust pipe 261. It is connected to the upstream side. The first vent pipe 215h, the second vent pipe 215s, and the third vent pipe 215o are provided with open / close valves vh5, vs5, and vo5, respectively, for controlling gas supply.

  In the above configuration, the gas flowing through the first source gas supply pipe 213h, the second source gas supply pipe 213s, and the ozone gas supply pipe 213o by closing the on-off valves vh3, vs3, vo3 and opening the on-off valves vh5, vs5, vo5. Without being supplied into the processing chamber 201, the processing chamber 201 can be bypassed and exhausted out of the processing chamber 201.

  The first purge gas supply pipe 214h, the second purge gas supply pipe 214s, and the third purge gas supply pipe 214o are upstream of the on-off valves vh4, vs4, vo4 and downstream of the flow rate controllers 224h, 224s, 224o. The fourth vent pipe 216h, the fifth vent pipe 216s, and the sixth vent pipe 216o are connected to each other. Further, the downstream end portions of the fourth vent pipe 216h, the fifth vent pipe 216s, and the sixth vent pipe 216o are unified so as to be joined to form a vent pipe 216, and the vent pipe 216 is a raw material recovery trap 263 of the exhaust pipe 261. Further, it is connected downstream of the vacuum pump 264 and upstream of the vacuum pump 264. The fourth vent pipe 216h, the fifth vent pipe 216s, and the sixth vent pipe 216o are provided with open / close valves vh6, vs6, and vo6 for controlling gas supply, respectively.

In the above configuration, the on-off valves vh4, vs4, vo4 are closed and the on-off valves vh6, vs6, vo6 are opened, so that N flows through the first purge gas supply pipe 214h, the second purge gas supply pipe 214s, and the third purge gas supply pipe 214o. It is possible to bypass the processing chamber 201 without supplying _two gases into the processing chamber 201 and to exhaust the gas out of the processing chamber 201. The gas flowing through the first source gas supply pipe 213h, the second source gas supply pipe 213s, and the ozone gas supply pipe 213o is closed by closing the on-off valves vh3, vs3, vo3 and opening the on-off valves vh5, vs5, vo5. When the processing chamber 201 is bypassed without being supplied into the processing chamber 201 and is exhausted to the outside of the processing chamber 201, the first source gas supply pipe 213h, the second 2 The raw material gas supply pipe 213s and the ozone gas supply pipe 213o are set to introduce N ₂ gas into the respective raw material gas supply pipes to be purged. The open / close valves vh6, vs6, vo6 are set so as to perform the reverse operation of the open / close valves vh4, vs4, vo4. When the N ₂ gas is not supplied into each raw material gas supply pipe, the processing chamber 201 is provided. By-pass N2 gas is exhausted.
Mainly, the first vent pipe 215h, the second vent pipe 215s, the third vent pipe 215o, the vent pipe 215, the fourth vent pipe 216h, the fifth vent pipe 216s, the sixth vent pipe 216o, the vent pipe 216, the open / close valve vh5 , Vs5, vo5 and open / close valves vh6, vs6, vo6 constitute a vent system (vent line).

<Controller (control unit)>
The substrate processing apparatus according to the present embodiment includes a controller 280 as a control unit that controls the operation of each unit of the substrate processing apparatus. The controller 280 includes a gate valve 251, an elevating mechanism 207b, a transfer robot 273, a heater 206, a pressure regulator (APC) 262, a vaporizer 229h, 229s, an ozonizer 229o, a vacuum pump 264, open / close valves vh1 to vh6, vs1 to vs6. The operations of vo3 to vo6, liquid flow rate controllers 221h and 221s, flow rate controllers 225h, 225s, 224h, 224s, 221o, 222o, 224o and the like are controlled.

(2) Substrate Processing Step Next, as one step of the manufacturing process of the semiconductor device according to the embodiment of the present invention, a substrate on which a thin film is formed on the wafer by the cyclic CVD method or the ALD method using the substrate processing device described above. The processing steps will be described with reference to FIGS. FIG. 5 is a flowchart of the substrate processing process according to the embodiment of the present invention. FIG. 2 is a sequence diagram as a timing chart showing the timings of source gas supply, ozone gas supply, support stand position change, and exhaust conductance change according to the embodiment of the present invention. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 280.

<Substrate Loading Step (S1), Substrate Placement Step (S2)>
First, the elevating mechanism 207b is operated to lower the support table 203 to the wafer transfer position shown in FIG. Then, the gate valve 251 is opened to allow the processing chamber 201 and the transfer chamber 271 to communicate with each other. Then, the wafer 200 to be processed is loaded from the transfer chamber 271 into the processing chamber 201 by the transfer robot 273 while being supported by the transfer arm 273a (S1). The wafer 200 carried into the processing chamber 201 is temporarily placed on the lift pins 208 b protruding from the upper surface of the support table 203. When the transfer arm 273a of the transfer robot 273 returns from the processing chamber 201 to the transfer chamber 271, the gate valve 251 is closed.

  Subsequently, the lifting mechanism 207 is operated to raise the support table 203 to the wafer processing position shown in FIG. As a result, the lift pins 208b are buried from the upper surface of the support table 203, and the wafer 200 is placed on the susceptor 217 on the upper surface of the support table 203 (S2).

<Pressure adjusting step (S3), temperature raising step (S4)>
Subsequently, the pressure regulator (APC) 262 controls the pressure in the processing chamber 201 to be a predetermined processing pressure (S3). Further, the power supplied to the heater 206 is adjusted, and the temperature of the wafer 200 is raised to control the surface temperature of the wafer 200 to a predetermined processing temperature (S4).

In the substrate loading step (S1), the substrate placement step (S2), the pressure adjustment step (S3), the temperature raising step (S4), and the substrate unloading step (S11) described later, while operating the vacuum pump 264, By closing the on-off valves vh3, vs3, and vo3 and opening the on-off valves vh4, vs4, and vo4, N ₂ gas is always allowed to flow into the processing chamber 201. Thereby, adhesion of particles on the wafer 200 can be suppressed. The vacuum pump 264 is always operated at least from the substrate loading step (S1) to the substrate unloading step (S11) described later.

In parallel with the steps S1 to S4, a first source gas (Hf source gas) obtained by vaporizing the first liquid source (Hf source) is generated (preliminarily vaporized). That is, while the on-off valve vh3 is closed, the on-off valve vh2 is opened, the carrier gas is supplied to the vaporizer 229h, the on-off valve vh1 is opened, and the pressurized gas is supplied from the pressurized gas supply pipe 237h. The first liquid source is pumped (supplied) from the source supply source 220h to the vaporizer 229h, and the first liquid source is vaporized by the vaporizer 229h to generate a first source gas. In this preliminary vaporization step, the process chamber 201 is bypassed without supplying the first source gas into the process chamber 201 by operating the vacuum pump 264 and opening the open / close valve vh5 while the open / close valve vh3 is closed. And exhaust. In the present embodiment, Hf [OC (CH ₃ ) ₂ CH ₂ OCH ₃ ] ₄ (hereinafter abbreviated as Hf (MMP) ₄ ) is used as the first liquid source (Hf source).

At this time, a second source gas (Si source gas) obtained by vaporizing the second liquid source (Si source) is also generated (preliminary vaporization). That is, while the on-off valve vs3 is closed, the on-off valve vs2 is opened, the carrier gas is supplied to the vaporizer 229s, the on-off valve vs1 is opened, and the pressurized gas is supplied from the pressurized gas supply pipe 237s to supply the second liquid. The second liquid source is pumped (supplied) from the source supply source 220s to the vaporizer 229s, and the second liquid source is vaporized by the vaporizer 229s to generate a second source gas. In this preliminary vaporization step, the process chamber 201 is bypassed without supplying the second source gas into the process chamber 201 by opening the open / close valve vs5 while operating the vacuum pump 264 and keeping the open / close valve vs3 closed. And exhaust. In the present embodiment, Si [OC (CH ₃ ) ₂ CH ₂ OCH ₃ ] ₄ (hereinafter abbreviated as Si (MMP) ₄ ) is used as the second liquid source (Si source).

  Further, at this time, it is preferable to generate ozone gas as a reactant. That is, oxygen gas is supplied from the oxygen gas supply source 230o to the ozonizer 229o, and ozone gas is generated in the ozonizer 229o. At this time, the vacuum pump 264 is operated and the open / close valve vo5 is opened while the open / close valve vo3 is closed, thereby bypassing and exhausting the process chamber 201 without supplying ozone gas into the process chamber 201.

  It takes a predetermined time to generate the first source gas and the second source gas in a stable state with the vaporizers 229h and 229s, or to generate the ozone gas in a stable state with the ozonizer 229o. That is, the raw material gas and the ozone gas are supplied in an unstable state at the initial generation of the raw material gas and the ozone gas. For this reason, in the present embodiment, the first source gas, the second source gas, and the ozone gas are generated in advance so that they can be stably supplied, and the open / close valves vh3, vh5, vs3, vs5, vo3, and vo5 are opened and closed. By switching, the flow paths of the first source gas, the second source gas, and the ozone gas are switched. As a result, the switching of the open / close valve is preferable because the stable supply of the first source gas, the second source gas, and the ozone gas into the processing chamber 201 can be started or stopped quickly.

<Raw material gas supply step (S6)>
Subsequently, the opening / closing valves vh4, vh5, vs4, vs5 are closed, the opening / closing valves vh3, vs3 are opened, and the supply of the first source gas and the second source gas into the processing chamber 201 is started. The first source gas and the second source gas are dispersed by the shower head 240 and are uniformly supplied onto the wafer 200 in the processing chamber 201. Excess first source gas and second source gas flow through the exhaust duct 259 and are exhausted to the exhaust port 260. Note that when the first source gas and the second source gas are supplied into the processing chamber 201, the first source gas and the second source gas are prevented from entering the ozone gas supply pipe 213o. In order to promote diffusion of the first source gas and the second source gas in the chamber, it is preferable that the opening / closing valve vo4 is kept open and the N ₂ gas is always allowed to flow into the processing chamber 201.

  After opening the on-off valves vh3, vs3 and starting the supply of the first source gas and the second source gas, when a predetermined time has elapsed, the on-off valves vh3, vs3 are closed, and the on-off valves vh4, vh5, vs4, vs5 are opened. Then, the supply of the first source gas and the second source gas into the processing chamber 201 is stopped. At the same time, the on-off valves vh1 and vs1 are closed, and the supply of the first liquid material and the second liquid material to the vaporizers 229h and 229s is also stopped.

<Purge process (S7)>
After closing the on-off valves vh3, vs3 and stopping the supply of the first source gas and the second source gas into the processing chamber 201, the on-off valves vh4, vs4, vo4 remain open, The supply of N ₂ gas is continued (see N ₂ gas in FIG. 2). The N ₂ gas is supplied into the processing chamber 201 through the shower head 240, flows in the exhaust duct 259, and is exhausted to the exhaust port 260. In this manner, the inside of the processing chamber 201 is purged with the N ₂ gas, and the first source gas and the second source gas remaining in the processing chamber 201 are removed.

  Simultaneously with the start of the purge step (S7), the lifting mechanism 207b is operated to start the lowering of the support base 203. The support table 203 is gradually lowered from the wafer processing position shown in FIG. 3 to an intermediate position between the wafer processing position and the wafer transfer position. At this time, the conductance plate 204 and the lower plate 205 are separated and separated, the upper surface portion of the recess 205b of the lower plate 205 is opened, and the exhaust conductance in the processing chamber is increased from the first exhaust conductance to the second larger than that. The exhaust conductance will be changed. Then, the support table 203 is held for a predetermined time at an intermediate position between the wafer processing position and the wafer transfer position. Thereafter, the support table 203 is gradually raised from an intermediate position between the wafer processing position and the wafer transfer position to the wafer processing position. At this time, the exhaust conductance in the processing chamber is changed (returned) from the second exhaust conductance to the first exhaust conductance. As described above, the purge step (S7) is performed in a state where the exhaust conductance in the processing chamber is set to the second exhaust conductance larger than the first exhaust conductance. Specifically, the purge step (S7) is performed while increasing the exhaust conductance in the processing chamber. After being broken, it is performed in a state where it is kept constant, and then it is performed while being lowered (see the support base position and the exhaust conductance in FIG. 2).

<Oxidant supply step (S8)>
When the purge in the processing chamber 201 is completed, the on-off valves vo4 and vo5 are closed, the on-off valve vo3 is opened, and supply of ozone gas as an oxidant into the processing chamber 201 is started (see O ₃ gas in FIG. 2). . The ozone gas is dispersed by the shower head 240 and is uniformly supplied onto the wafer 200 in the processing chamber 201. Excess ozone gas and reaction byproducts flow through the exhaust duct 259 and are exhausted to the exhaust port 260. When ozone gas is supplied into the processing chamber 201, the ozone gas is prevented from entering the first source gas supply pipe 213h and the second source gas supply pipe 213s, and the ozone gas is diffused in the processing chamber 201. It is preferable to keep the open / close valves vh4 and vs4 open so that the N ₂ gas always flows into the processing chamber 201.

When a predetermined time has elapsed after opening the on-off valve vo3 and starting the supply of ozone gas, the on-off valve vo3 is closed and the on-off valves vo4, vo5 are opened to stop the supply of ozone gas into the processing chamber 201 (FIG. 2). O ₃ gas).

<Purge process (S9)>
After closing the on-off valve vo3 and stopping the supply of ozone gas into the processing chamber 201, the on-off valves vh4, vs4, vo4 are kept open and the supply of N ₂ gas into the processing chamber 201 is continued. (See N2 gas in FIG. 2). The N ₂ gas is supplied into the processing chamber 201 through the shower head 240, flows in the exhaust duct 259, and is exhausted to the exhaust port 260. In this manner, the inside of the processing chamber 201 is purged with N ₂ gas, and ozone gas and reaction byproducts remaining in the processing chamber 201 are removed.

  Simultaneously with the start of the purge step (S9), the lifting mechanism 207b is operated to start the lowering of the support base 203. The support table 203 is gradually lowered from the wafer processing position shown in FIG. 3 to an intermediate position between the wafer processing position and the wafer transfer position. At this time, the conductance plate 204 and the lower plate 205 are separated and separated, the upper surface portion of the recess 205b of the lower plate 205 is opened, and the exhaust conductance in the processing chamber is increased from the first exhaust conductance to the second larger than that. The exhaust conductance will be changed. Then, the support table 203 is held for a predetermined time at an intermediate position between the wafer processing position and the wafer transfer position. Thereafter, the support table 203 is gradually raised from an intermediate position between the wafer processing position and the wafer transfer position to the wafer processing position. At this time, the exhaust conductance in the processing chamber is changed (returned) from the second exhaust conductance to the first exhaust conductance. As described above, the purge step (S9) is performed in a state where the exhaust conductance in the processing chamber is set to the second exhaust conductance larger than the first exhaust conductance. Specifically, the purge step (S9) is performed while increasing the exhaust conductance in the processing chamber. After being broken, it is performed in a state where it is kept constant, and then it is performed while being lowered (see the support base position and the exhaust conductance in FIG. 2).

  In parallel with the oxidant supply step (S8) or the purge step (S9), the first source gas and the second source gas are generated (preliminary vaporization).

<Repetition step (S10)>
Then, the steps S6 to S9 are set as one cycle, and this cycle is repeated a predetermined number of times, whereby a hafnium silicate (HfSiOx) thin film having a desired film thickness is formed on the wafer 200 (thin film forming step).

  In the above thin film forming step, following the raw material supply step (S6), a purge step (S7) is performed in a state where the exhaust conductance in the processing chamber is set to the second exhaust conductance, and following the oxidant supply step (S8). By performing the purge step (S9) with the exhaust conductance in the processing chamber set to the second exhaust conductance, the unreacted (surplus) raw material is processed in the purge step (S7) following the raw material supply step (S6). In the purge step (S9) following the oxidant supply step (S8), unreacted (surplus) reactive species (ozone) can be efficiently discharged from the processing chamber. it can.

  As described above, by changing (increasing) the exhaust conductance in the processing chamber in the purge process, the gas replacement efficiency can be improved, the purge time can be shortened, and the throughput (productivity) can be improved. It becomes possible.

  In the source gas supply step (S6), the example in which the first source gas and the second source gas are supplied simultaneously has been described. However, the first source gas and the second source gas may be supplied separately. That is, a first source gas supply step (S6h) for supplying a first source gas, a purge step (S7h), a second source gas supply step (S6s) for supplying a second source gas, a purge step (S7s), an oxidant The supply step (S8) and the purge step (S9) may be one cycle, and this cycle may be repeated a plurality of times to form a hafnium silicate (HfSiOx) thin film having a desired thickness on the wafer 200. In this case, with the support table 203 held at the wafer processing position and the exhaust conductance in the processing chamber set to the first exhaust conductance, the first source gas supply step (S6h), the second source gas supply step (S6s), An oxidant supply step (S8) is performed, the support stage 203 is lowered, and the exhaust conductance in the processing chamber is set to the second exhaust conductance, the purge step (S7h), the purge step (S7s), the purge step ( S9) will be performed.

<Substrate unloading step (S11)>
Thereafter, the wafer 200 after forming the HfSiOx film having a desired film thickness is transferred from the processing chamber 201 to the transfer chamber by a procedure reverse to the procedure shown in the substrate loading step (S1) and the substrate placement step (S2). Then, the substrate processing step according to the present embodiment is completed.

  In addition, when performing a thin film formation process by cyclic CVD method, it controls so that processing temperature may become a temperature range which is a grade which source gas self-decomposes. In this case, in the source gas supply step (S 6), the source gas is self-decomposed and a thin film of about 1 to several tens of atomic layers is formed on the substrate 200. In the oxidant supply step, impurities such as C and H are removed from a thin film of about 1 to several tens of atomic layers formed on the substrate 200 by ozone gas.

  Further, when the thin film forming process is performed by the ALD method, the processing temperature is controlled so as to be a temperature range in which the source gas is not self-decomposed. In this case, the source gas is adsorbed on the substrate 200 in the source gas supply step. In the oxidant supply step, the raw material adsorbed on the substrate 200 reacts with ozone gas, whereby a thin film having less than one atomic layer is formed on the substrate 200. At this time, impurities such as C and H to be mixed into the thin film can be desorbed by ozone gas.

In the processing furnace of the present embodiment, the processing conditions for processing the substrate by cyclic CVD are as follows. For example, when a HfSiOx film is formed, processing temperature: 390 to 450 ° C., processing pressure: 50 ~ 400 Pa, first raw material (Hf (MMP) ₄ ) supply flow rate: 0.01 to 0.2 g / min, second raw material (Si (MMP) ₄ ) supply flow rate: 0.01 to 0.2 g / min, oxidation Agent (ozone gas) supply flow rate: 100 to 3000 sccm is exemplified.

In addition, as a processing condition for processing a substrate by the ALD method in the processing furnace of the present embodiment, for example, when a HfSiOx film is formed, a processing temperature: 200 to 350 ° C., a processing pressure: 50 to 400 Pa. , First raw material (Hf (MMP) ₄ ) supply flow rate: 0.01 to 0.2 g / min, second raw material (Si (MMP) ₄ ) supply flow rate: 0.01 to 0.2 g / min, oxidizing agent ( Ozone gas) supply flow rate: 100 to 3000 sccm is exemplified.

In the above embodiment, an example has been described using Hf (MMP) ₄ as the first source, the first raw material, instead of _{Hf (MMP) 4, Hf [} OC (CH 3) 3] 4 An organic raw material such as (Hf (OtBu) ₄ ) may be used. In the above-described embodiment, an example in which Si (MMP) ₄ is used as the second raw material has been described. However, as the second raw material, Si [OC ₂ H ₅ ] ₄ (TEOS) is used instead of Si (MMP) _4. An organic raw material such as

In the above-described embodiment, an example in which O ₃ gas is used as the oxidant has been described. However, as the oxidant, oxygen-containing gas such as O ₂ gas or H ₂ O gas activated by plasma instead of O ₃ gas is used. May be used. Incidentally, the H ₂ O gas is compared with the O ₃ gas, so easily hardly desorbed adsorbed member of the processing chamber, the present invention is used for the H ₂ O gas as an oxidizing agent is particularly effective. That is, according to the present invention, even when H ₂ O gas is used as the oxidant, the discharge time of H ₂ O gas from the processing chamber can be shortened and productivity can be improved. In this case, in the purge step (S7) following the raw material supply step (S6), the exhaust conductance in the processing chamber is not changed to the first exhaust conductance, and only the purge step (S9) following the oxidant supply step (S8). The exhaust conductance in the processing chamber may be set to the second exhaust conductance.

200 wafer (substrate)
201 processing chamber 203 support base 204 conductance plate 205 lower plate 206 heater 207b lifting mechanism 213h first source gas supply pipe 213s second source gas supply pipe 214 purge gas supply pipe 217 susceptor 260 exhaust port 261 exhaust pipe

Claims (2)

Evacuating the processing chamber while supplying a source gas into the processing chamber in a state where the exhaust conductance in the processing chamber containing the substrate is the first exhaust conductance;
Purging the processing chamber by exhausting the processing chamber while supplying a purge gas to the processing chamber in a state where the exhaust conductance in the processing chamber is set to a second exhaust conductance larger than the first exhaust conductance. When,
Evacuating the processing chamber while supplying the oxidant into the processing chamber with the exhaust conductance in the processing chamber being the first exhaust conductance;
Purging the processing chamber by exhausting the processing chamber while supplying a purge gas to the processing chamber in a state where the exhaust conductance in the processing chamber is the second exhaust conductance;
Is a cycle, and this cycle is repeated a plurality of times. A processing chamber for processing the substrate;
A raw material gas supply system for supplying a raw material gas into the processing chamber;
An oxidizing agent supply system for supplying an oxidizing agent into the processing chamber;
A purge gas supply system for supplying a purge gas into the processing chamber;
An exhaust system for exhausting the processing chamber;
An exhaust conductance adjusting unit for adjusting the exhaust conductance in the processing chamber;
With the exhaust conductance in the processing chamber set to the first exhaust conductance, the processing chamber is exhausted while supplying the source gas into the processing chamber, and the exhaust conductance in the processing chamber is set to be higher than the first exhaust conductance. In a state where the second exhaust conductance is large, the process chamber is purged by exhausting the process chamber while supplying a purge gas into the process chamber, and the exhaust conductance in the process chamber is set as the first exhaust conductance. In the state, the processing chamber is exhausted while supplying the oxidizing agent into the processing chamber, and the exhaust gas conductance in the processing chamber is set to the second exhaust conductance, and the processing gas is supplied while purging gas is supplied into the processing chamber. The processing chamber is purged by exhausting the chamber, and this is defined as one cycle. As repeated a plurality of times, and the raw material gas supply system, the oxidant supply system, the purge gas supply system, the exhaust system, and a control unit for controlling the exhaust conductance adjustment unit,
A substrate processing apparatus comprising: