JP2014194081A - Manufacturing method of semiconductor device, substrate treatment method, substrate treatment apparatus, semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a semiconductor device, which allows reducing a residual impurity in a film without giving plasma damage, improving flatness of the film, and improving deposition rate while usage amount of a precursor is suppressed, and a substrate treatment apparatus.SOLUTION: A manufacturing method includes steps of: forming an insulator film on a substrate; forming an insulator film with a high dielectric constant on the insulator film; forming an aluminum nitride titanium film on the insulator film with the high dielectric constant. In the step of forming the aluminum nitride titanium film, formation of an aluminum nitride film and a titanium nitride film are alternately repeated, in which the aluminum nitride film is formed firstly and/or lastly.

Description

  The present invention relates to a method for manufacturing a semiconductor device and a substrate processing apparatus, and more particularly to a method for manufacturing a semiconductor device including a step of forming a metal film on a substrate and a substrate processing apparatus for forming a metal film on a substrate.

  In the Metal / High-k gate stack, the high temperature heat treatment causes a problem that the effective work function of the metal gate electrode shifts to the mid gap due to the Fermi level pinning phenomenon. This phenomenon particularly appears in the p-MOSFET. As a method for avoiding this, studies have been conducted on the use of a metal composite film such as a Metal-Al-N film as the gate electrode. Examples of the Metal-Al-N film include a TiAlN film and a RuAlN film.

  As a conventional method for forming a metal composite film, an ALD method in which two precursors and a reactive gas are alternately supplied is a mainstream (see, for example, Non-Patent Documents 1 and 2). Non-Patent Documents 1 and 2 disclose an example in which a film is formed by a PEALD (Plasma Enhanced ALD) method using plasma.

Yong Ju Lee and Sang-Won Kang: Electrochemical and Solid-State Letters, 6 (5) C70-C72 (2003) “Ti-Al-N Thin Films Prepared by the Combination of Metallorganic Plasma-Enhanced Atomic Layer Deposition of Al and TiN ” Yong Ju Lee and Sang-Won Kang: J.Vac.Sci.Technol.A, Vol.21, No.5, Sep / Oct 2003 “Controlling the composition of Ti1-XAlXN thin films by modifying the number of TiN and AlN subcycles in atomic layer deposition ”

  However, when the metal composite film is formed by the ALD method, there is a problem that residual impurities derived from the precursor cannot be removed due to the low processing temperature. On the other hand, the metal composite film is formed by PEALD method using plasma as in Non-Patent Document 1, but when the film is formed by PALD method, the flatness of the film may be deteriorated. In addition, since plasma is used, when it is applied to the formation of a gate electrode, there is a concern about plasma damage to the gate insulating film or the like and an increase in EOT.

  In addition, when a metal composite film is formed by the ALD method by alternately supplying two kinds of precursors and a reactive gas, the deposition speed becomes a problem, and it takes a lot of time and a precursor to form the metal composite film. There is a big problem.

  Therefore, the present invention can reduce the residual impurities in the film without causing plasma damage, improve the flatness of the film, and further manufacture a semiconductor device capable of improving the deposition rate while suppressing the amount of precursor used. It is an object to provide a method and a substrate processing apparatus.

According to one aspect of the present invention, an insulating film is formed on a substrate, a high dielectric constant insulating film is formed on the insulating film, and an aluminum titanium nitride film is formed on the high dielectric constant insulating film. In the step of forming the aluminum titanium nitride film, the formation of the aluminum nitride film and the formation of the titanium nitride film are alternately repeated. At this time, the nitridation is performed first and / or last. A method of manufacturing a semiconductor device for forming an aluminum film is provided. Here, the high dielectric constant insulating film means an insulating film having a relative dielectric constant higher than that of SiO ₂ (about 4). In addition, the formation of the aluminum nitride film at the beginning and / or the last is that the aluminum nitride film is formed first (AlN first), the aluminum nitride film is formed last (AlN last), or the first Finally, it means that the aluminum nitride film is formed (AlN first last).

  According to another aspect of the present invention, an insulating film is formed on a substrate, a high dielectric constant insulating film is formed on the insulating film, and an aluminum titanium nitride film is formed on the high dielectric constant insulating film. Forming the aluminum titanium nitride film, and forming the aluminum nitride film by the ALD method and forming the titanium nitride film by the CVD method in the same processing chamber. Provided is a method of manufacturing a semiconductor device in which the aluminum nitride film is formed at the beginning and / or at the end, alternately and repeatedly with the temperature set at the same temperature, with the purge in the processing chamber interposed therebetween. The

  According to still another aspect of the present invention, there is provided a processing chamber for processing a substrate having a high dielectric constant insulating film formed on the surface via an insulating film, and a first raw material containing aluminum atoms is supplied into the processing chamber. A raw material supply system, a second raw material supply system for supplying a second raw material containing titanium atoms into the processing chamber, a reactive gas supply system for supplying a reactive gas containing nitrogen atoms into the processing chamber, A heater for heating a substrate; formation of an aluminum nitride film by supplying the first raw material and the reactive gas into the processing chamber; and forming a titanium nitride film by supplying the second raw material and the reactive gas into the processing chamber. The aluminum nitride titanium film is formed on the high dielectric constant insulating film formed on the substrate by alternately and repeatedly forming the aluminum nitride film. So as to form a um membrane, the first raw material supply system, said second source supply system, the reactive gas supply system, and a substrate processing apparatus is provided with a controller for controlling the heater.

  According to the method for manufacturing a semiconductor device and the substrate processing apparatus according to the present invention, it is possible to reduce residual impurities in the film without causing plasma damage, improve the flatness of the film, and further suppress the use amount of the precursor. The deposition rate can be improved.

It is a film-forming sequence diagram in the substrate processing process concerning the embodiment of the present invention. It is a block diagram of the gas supply system which the substrate processing apparatus concerning embodiment of this invention has. It is a section lineblock diagram at the time of wafer processing of a substrate processing device concerning an embodiment of the present invention. It is a section lineblock diagram at the time of wafer conveyance of a substrate processing device concerning an embodiment of the present invention. It is a flowchart of the substrate processing process concerning embodiment of this invention. Is a diagram showing the evaluation results of Example 1, (a) shows HfSiON, AlN, the TDMAT supply time dependence of CVD-TiN film thickness of on SiO ₂ in the CVD-TiN film formation, (b ) Shows the ALD cycle number dependence of the ALD-AlN film thickness on HfSiON, TiN, and SiO ₂ in ALD-AlN film formation. It is a figure which shows the evaluation result of Example 2, (a) repeats ALD-AlN film-forming and CVD-TiN film-forming, and after forming the laminated film which consists of 5 layers, 11 layers, and 21 layers 4A and 4B show cross-sectional TEM photographs, respectively, in which (b) repeats ALD-AlN film formation and CVD-TiN film formation to form a laminated film of five layers, eleven layers, and twenty-one layers, and 900 ° C. after the N ₂ annealing in shows the respective cross-sectional TEM photograph. Is a diagram showing the evaluation results of Example 3, (a) forms a laminated film composed of 11 layers, it shows the XPS depth profile after the N ₂ annealing at 900 ° C., (b ) Shows an XPS depth direction profile after forming a laminated film of 21 layers and performing N ₂ annealing at 900 ° C. It is a figure which shows the evaluation result of Example 4, (a) is a figure which shows the ALD-AlN cycle number dependence of Al / Ti density | concentration in a TiAlN film | membrane, (b) is an Al density | concentration dependence of resistivity. FIG. Is a diagram showing the evaluation results of Examples. 5, (a) shows the, by repeating the CVD-TiN film formation and ALD-AlN film formation to form a TiAlN film, SEM photographs after the _{N 2} annealing at 900 ° C. (B) shows a cross-sectional TEM photograph after forming a TiAlN film by repeating CVD-TiN film formation and ALD-AlN film formation and performing N ₂ annealing at 900 ° C. c) shows an AFM photograph after forming a TiAlN film by repeating CVD-TiN film formation and ALD-AlN film formation and performing N ₂ annealing at 900 ° C. It is a figure which shows the evaluation result of Example 6, (a) is the gate structure (evaluation sample) of the p-MOSFET which applied the TiAlN film | membrane formed by repeating CVD-TiN film-forming and ALD-AlN film-forming to a gate electrode. (B) shows the condition when the TiAlN film is formed by repeating the CVD-TiN film formation and the ALD-AlN film formation and the laminated structure, and (c) shows the effective work. It is a figure which shows Al concentration dependence in the TiAlN film | membrane of a function. It is a figure which shows the evaluation result of Example 7, (a) is the gate structure (evaluation sample) of the p-MOSFET which applied the TiAlN film | membrane formed by repeating CVD-TiN film-forming and ALD-AlN film-forming to a gate electrode. (B) and (c) show the condition when the TiAlN film is formed by repeating the CVD-TiN film formation and the ALD-AlN film formation, and the laminated structure thereof, (d) These are figures which show the Al concentration dependence in the TiAlN film | membrane of an effective work function. It is a figure which shows the evaluation result of Example 7, (a) is the gate structure (evaluation sample) of the p-MOSFET which applied the TiAlN film | membrane formed by repeating CVD-TiN film-forming and ALD-AlN film-forming to a gate electrode. (B) and (c) show the condition when the TiAlN film is formed by repeating the CVD-TiN film formation and the ALD-AlN film formation, and the laminated structure thereof, (d) These are figures which show the Al concentration dependence in the TiAlN film | membrane of an effective work function. (A) is a figure which shows the time-dependent change of the oxidation degree of the TiAlN film which used the uppermost layer as the CVD-TiN film, and (b) is the time change of the degree of oxidation of the TiAlN film which used the uppermost layer as the ALD-AlN film. FIG. It is a schematic block diagram of the vertical processing furnace of the vertical ALD apparatus used suitably by this embodiment, (a) shows the processing furnace 302 part in a longitudinal cross section, (b) is a figure showing the processing furnace 302 part. It is shown by the AA line sectional view of 15 (a). It is a film-forming sequence diagram in the substrate processing process concerning further another embodiment of the present invention.

(1) Configuration of Substrate Processing Apparatus 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 one embodiment of the present invention during wafer processing, and FIG. 4 is a cross-sectional configuration diagram of the substrate processing apparatus according to one embodiment of the present invention during wafer transfer. is there.

(Processing room)
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 such as a silicon wafer 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 (heating source) 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. 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 ends of the lift pins 208b protrude 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, and 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 (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 moves the wafer 200 between the load lock chamber and the transfer chamber 271. Can be transported. 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) that controls 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 processing chamber 201. 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)
A step portion 201a is provided on the side surface of the inner wall of the processing chamber 201 (processing vessel 202). 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 (the conductance plate 204 and the lower plate 205) and the support base 203, the inside of the processing chamber 201 is above the processing chamber above the exhaust duct 259 and the processing chamber below the exhaust duct 259. It will be partitioned into a lower part. 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. Then, 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 toward the radially outer side 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 part of the processing chamber, that is, the back surface of the support base 203 or the bottom surface side of the processing chamber 201 is suppressed.

<Gas supply system>
Next, the configuration of the gas supply system connected to the gas inlet 210 described above will be described with reference to FIG. FIG. 2 is a configuration diagram of a gas supply system (gas supply line) included in the substrate processing apparatus according to the embodiment of the present invention.

  A gas supply system included in a substrate processing apparatus according to an embodiment of the present invention includes a bubbler as a vaporization unit that vaporizes a liquid raw material that is in a liquid state at room temperature, and a raw material gas obtained by vaporizing the liquid raw material in the bubbler A source gas supply system for supplying the reaction gas into the chamber 201 and a reaction gas supply system for supplying a reaction gas different from the source gas into the processing chamber 201 are provided. Further, the substrate processing apparatus according to the embodiment of the present invention bypasses the processing chamber 201 without supplying the purge gas supply system for supplying the purge gas into the processing chamber 201 and the source gas from the bubbler into the processing chamber 201. And a vent (bypass) system for exhausting. Below, the structure of each part is demonstrated.

<Bubbler>
Outside the processing chamber 201, a first raw material container (first bubbler) 220a for storing a first raw material (raw material A) as a liquid raw material and a second raw material (raw material B) as a liquid raw material are supplied. A raw material container (second bubbler) 220b is provided. The first bubbler 220a and the second bubbler 220b are each configured as a tank (sealed container) capable of containing (filling) a liquid material therein, and also vaporizing the liquid material by bubbling to generate a material gas. It is also configured as a part. Around the first bubbler 220a and the second bubbler 220b, there are provided a first heater 220a, a second bubbler 220b, and a sub-heater 206a for heating the liquid material inside. As the first raw material, for example, TDMAT (Tetrakis-Dimethyl-Amido-Titanium) which is an organometallic liquid raw material containing Ti (titanium) element is used, and as the second raw material, for example, an organic material containing Al (aluminum) element is used. TMA (Trimethylaluminium) which is a metal liquid raw material is used.

A first carrier gas supply pipe 237a and a second carrier gas supply pipe 237b are connected to the first bubbler 220a and the second bubbler 220b, respectively. A carrier gas supply source (not shown) is connected to upstream ends of the first carrier gas supply pipe 237a and the second carrier gas supply pipe 237b. Further, the downstream end portions of the first carrier gas supply pipe 237a and the second carrier gas supply pipe 237b are immersed in the liquid raw materials accommodated in the first bubbler 220a and the second bubbler 220b, respectively. The first carrier gas supply pipe 237a is provided with a mass flow controller (MFC) 222a as a flow rate controller for controlling the supply flow rate of the carrier gas, and valves va1 and va2 for controlling the supply of the carrier gas. The second carrier gas supply pipe 237b is provided with a mass flow controller (MFC) 222b as a flow rate controller for controlling the supply flow rate of the carrier gas, and valves vb1 and vb2 for controlling the supply of the carrier gas. As the carrier gas, it is preferable to use a gas that does not react with the liquid raw material. For example, an inert gas such as N ₂ gas or Ar gas is preferably used. The first carrier gas supply system, the second carrier gas supply pipe 237a, the second carrier gas supply pipe 237b, the MFCs 222a and 222b, and the valves va1, va2, vb1, and vb2 Gas supply line, second carrier gas supply line).

  With the above configuration, the valves va1, va2, vb1, vb2 are opened, and the carrier gas whose flow rate is controlled by the MFCs 222a, 222b from the first carrier gas supply pipe 237a and the second carrier gas supply pipe 237b is supplied to the first bubbler 220a, the second bubbler. By supplying it into 220b, it becomes possible to vaporize the liquid raw material accommodated in the first bubbler 220a and the second bubbler 220b by bubbling to generate a raw material gas. Note that the supply flow rate of the source gas can be determined from the supply flow rate of the carrier gas. That is, the supply flow rate of the source gas can be controlled by controlling the supply flow rate of the carrier gas.

<Raw gas supply system>
The first bubbler 220a and the second bubbler 220b include a first source gas supply pipe 213a and a second source gas supply pipe that supply the source gas generated in the first bubbler 220a and the second bubbler 220b into the processing chamber 201, respectively. 213b are connected to each other. The upstream end portions of the first source gas supply pipe 213a and the second source gas supply pipe 213b communicate with a space existing above the first bubbler 220a and the second bubbler 220b. The downstream end portions of the first source gas supply pipe 213a and the second source gas supply pipe 213b merge and are connected to the gas inlet 210 via the high durability high speed gas valve V. The high durability high-speed gas valve V is a valve configured to be able to quickly switch gas supply and exhaust gas in a short time. The first source gas supply pipe 213a and the second source gas supply pipe 213b are provided with valves va3 and vb3 for controlling the supply of the source gas into the processing chamber 201, respectively.

  With the above configuration, the first raw material gas supply pipe 213a and the second raw material gas supply are generated by opening the valves va3 and vb3 while generating the raw material gas by vaporizing the liquid raw material in the first bubbler 220a and the second bubbler 220b. The source gas can be supplied into the processing chamber 201 from the tube 213b. The first source gas supply system, the second source gas supply system (first source gas supply line) is mainly configured by the first source gas supply pipe 213a, the second source gas supply pipe 213b, the valves va3 and vb3, and the high durability high-speed gas valve V. , A second source gas supply line).

  In addition, mainly, the first source gas supply system, the second carrier gas supply system, the first bubbler 220a, the second bubbler 220b, the first source gas supply system, the second source gas supply system, the first source gas supply system, Second raw material supply systems (first raw material supply line and second raw material supply line) are configured.

<Reactive gas supply system>
In addition, a reaction gas supply source 220 c that supplies a reaction gas is provided outside the processing chamber 201. The upstream end of the reactive gas supply pipe 213c is connected to the reactive gas supply source 220c. The downstream end of the reaction gas supply pipe 213c is connected to the gas inlet 210 through a highly durable high-speed gas valve V. The reaction gas supply pipe 213c is provided with a mass flow controller (MFC) 222c as a flow rate controller for controlling the supply flow rate of the reaction gas, and valves vc1 and vc2 for controlling the supply of the reaction gas. As the reaction gas, for example, ammonia (NH ₃ ) gas is used. A reactive gas supply system (reactive gas supply line) is mainly configured by the reactive gas supply source 220c, the reactive gas supply pipe 213c, the MFC 222c, and the valves vc1 and vc2.

<Purge gas supply system>
Further, purge gas supply sources 220d and 220e for supplying purge gas are provided outside the processing chamber 201. The upstream ends of the purge gas supply pipes 213d and 213e are connected to the purge gas supply sources 220d and 220e, respectively. The downstream end of the purge gas supply pipe 213d merges with the reaction gas supply pipe 213c and is connected to the gas inlet 210 through the high durability high speed gas valve V. The downstream end of the purge gas supply pipe 213e joins the first source gas supply pipe 213a and the second source gas supply pipe 213b, and is connected to the gas inlet 210 via the high durability high speed gas valve V. The purge gas supply pipes 213d and 213e are provided with mass flow controllers (MFC) 222d and 222e as flow rate controllers for controlling the supply flow rate of the purge gas, and valves vd1, vd2, ve1 and ve2 for controlling the supply of the purge gas, respectively. Yes. As the purge gas, for example, an inert gas such as N ₂ gas or Ar gas is used. A purge gas supply system (purge gas supply line) is mainly configured by the purge gas supply sources 220d and 220e, the purge gas supply pipes 213d and 213e, the MFCs 222d and 222e, and the valves vd1, vd2, ve1, and ve2.

<Vent (bypass) system>
Further, upstream ends of the first vent pipe 215a and the second vent pipe 215b are connected to the upstream side of the valves va3 and vb3 of the first source gas supply pipe 213a and the second source gas supply pipe 213b, respectively. Yes. Further, the downstream end portions of the first vent pipe 215a and the second vent pipe 215b merge to be connected downstream of the pressure regulator 262 of the exhaust pipe 261 and upstream of the material recovery trap 263. Yes. The first vent pipe 215a and the second vent pipe 215b are provided with valves va4 and vb4 for controlling the gas flow, respectively.

  With the above configuration, the valves va3 and vb3 are closed and the valves va4 and vb4 are opened, so that the gas flowing in the first source gas supply pipe 213a and the second source gas supply pipe 213b is not supplied into the processing chamber 201. Then, the processing chamber 201 can be bypassed via the first vent pipe 215a and the second vent pipe 215b, and exhausted from the exhaust pipe 261 to the outside of the processing chamber 201, respectively. A first vent system and a second vent system (a first vent line and a second vent line) are mainly configured by the first vent pipe 215a, the second vent pipe 215b, and the valves va4 and vb4.

  As described above, the sub-heater 206a is provided around the first bubbler 220a and the second bubbler 220b. In addition, the first carrier gas supply pipe 237a, the second carrier gas supply pipe 237b, and the first raw material are provided. A sub-heater 206a is also provided around the gas supply pipe 213a, the second source gas supply pipe 213b, the first vent pipe 215a, the second vent pipe 215b, the exhaust pipe 261, the processing vessel 202, the shower head 240, and the like. The sub-heater 206a is configured to prevent re-liquefaction of the source gas inside these members by heating these members to a temperature of, for example, 100 ° C. or less.

<Controller>
Note that the substrate processing apparatus according to the present embodiment includes a controller 280 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 sub heater 206a, a pressure regulator (APC) 262, a vacuum pump 264, valves va1 to va4, vb1 to vb4, vc1 to vc2, and vd1 to vd2. , Ve1 to ve2, the high durability high speed gas valve V, the flow controllers 222a, 222b, 222c, 222d, 222e and the like are controlled.

(2) Substrate Processing Step Subsequently, as a step of the manufacturing process of the semiconductor device according to the embodiment of the present invention, a thin film is formed on the wafer using the above-described substrate processing apparatus in combination with the CVD method and the ALD method. The substrate processing process 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. 1 is a film forming sequence diagram of the CVD process and the ALD process in the substrate processing process 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.

Here,
A first raw material (TDMAT) containing a first metal atom (Ti) is supplied to the substrate, and a first metal film (TiN film) containing the first metal atom (Ti) is applied to the substrate by a CVD method. CVD process for forming
The step of supplying the second raw material (TMA) containing the second metal atom (Al) to the substrate and the step of supplying the reaction gas (NH ₃ ) to the substrate are defined as one cycle. An ALD step of performing a predetermined number of times and forming a second metal film (AlN film) containing a second metal atom (Al) on the substrate by an ALD method;
An example of forming a third metal film (TiAlN film) containing the first metal atom (Ti) and the second metal atom (Al) by repeating the above will be described. In this specification, the term metal film (metal film) means a conductive substance containing a metal (metal) atom. This includes a conductive film in addition to a film made of a single metal. Also included are metal nitride films, metal oxide films, metal composite films, metal alloy films, and the like. This will be described in detail below.

<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 elevating mechanism 207b 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 to control the surface temperature of the wafer 200 to a predetermined processing temperature (S4). Here, the predetermined processing temperature and processing pressure are processing temperature and processing pressure at which a TiN film can be formed by a CVD method in a CVD-TiN process described later, and in the ALD-AlN process described later, ALD This is the processing temperature and processing pressure at which an AlN film can be formed by the method. That is, the processing temperature and the processing pressure are such that the first source gas used in the CVD-TiN process is self-decomposed, and the second source gas used in the ALD-AlN process is not so self-decomposing. .

In the substrate loading step (S1), the substrate placement step (S2), the pressure adjustment step (S3), and the temperature raising step (S4), the valves va3, vb3, vc2 are closed while the vacuum pump 264 is operated. By opening the valves vd1, vd2, ve1, and ve2, N ₂ gas is always allowed to flow into the processing chamber 201. Thereby, adhesion of particles on the wafer 200 can be suppressed.

  In parallel with the steps S1 to S4, the first raw material is vaporized to generate the first raw material gas (preliminary vaporization). That is, by opening the valves va1 and va2 and supplying the carrier gas whose flow rate is controlled by the MFC 222a from the first carrier gas supply pipe 237a into the first bubbler 220a, the first raw material contained in the first bubbler 220a is supplied. Vaporization is performed to generate the first source gas (preliminary vaporization step). In this preliminary vaporization step, while the vacuum pump 264 is operated, the valve va4 is opened while the valve va3 is closed, thereby bypassing the processing chamber 201 and exhausting it without supplying the first source gas into the processing chamber 201. Keep it. A predetermined time is required to stably generate the first source gas in the first bubbler. Therefore, in the present embodiment, the first source gas is generated in advance, and the flow path of the first source gas is switched by switching the opening and closing of the valves va3 and va4. As a result, it is preferable that the stable supply of the first source gas into the processing chamber 201 can be started or stopped quickly by switching the valve.

<CVD-TiN process (S6)>
(First source gas supply process)
Subsequently, the valve va4 is closed and the valve va3 is opened while the vacuum pump 264 is operated, and the supply of the first source gas (Ti source) into the processing chamber 201 is started. The first source gas is dispersed by the shower head 240 and is uniformly supplied onto the wafer 200 in the processing chamber 201. Excess first source gas flows through the exhaust duct 259 and is exhausted to the exhaust port 260 and the exhaust pipe 261 (first source gas supply step). At this time, since the processing temperature and the processing pressure are set to a processing temperature and processing pressure at which the first source gas is self-decomposed, a CVD reaction occurs when the first source gas supplied onto the wafer 200 is thermally decomposed, As a result, a TiN film is formed on the wafer 200.

When the first source gas is supplied into the processing chamber 201, the first source gas is diffused in the processing chamber 201 so as to prevent the first source gas from entering the reaction gas supply pipe 213c. It is preferable to keep the valves vd1 and vd2 open so that the N ₂ gas always flows into the processing chamber 201 so as to facilitate the operation.

  After the valve va3 is opened and the supply of the first source gas is started, when a predetermined time has elapsed and a TiN film having a desired film thickness is formed, the valve va3 is closed, the valve va4 is opened, and the first chamber into the processing chamber 201 is opened. (1) Supply of raw material gas is stopped. At the same time, the valves va1 and va2 are closed, and the supply of the carrier gas to the first bubbler 220a is also stopped.

(Purge process)
After the valve va3 is closed and the supply of the first source gas is stopped, the valves vd1, vd2, ve1, and ve2 are opened, and N ₂ gas is supplied into the processing chamber 201. The N ₂ gas is dispersed by the shower head 240 and supplied into the processing chamber 201, flows through the exhaust duct 259, and is exhausted to the exhaust port 260 and the exhaust pipe 261. As a result, the first raw material gas and reaction byproducts remaining in the processing chamber 201 are removed, and the inside of the processing chamber 201 is purged with N ₂ gas (purge process).

  In the CVD-TiN step (S6), in preparation for the next ALD-AlN step (S8), the second raw material gas is vaporized to generate (preliminary vaporization). That is, by opening the valves vb1 and vb2 and supplying the carrier gas whose flow rate is controlled by the MFC 222b from the second carrier gas supply pipe 237b into the second bubbler 220b, the second raw material contained in the second bubbler 220b is obtained. Vaporization is performed to generate a second source gas (preliminary vaporization step). In this preliminary vaporization step, while the vacuum pump 264 is operated, the valve vb4 is opened while the valve vb3 is closed, thereby bypassing the process chamber 201 and exhausting it without supplying the second source gas into the process chamber 201. Keep it. A predetermined time is required to stably generate the second source gas in the second bubbler. Therefore, in the present embodiment, the second source gas is generated in advance, and the flow path of the second source gas is switched by switching the opening and closing of the valves vb3 and vb4. As a result, it is preferable that the stable supply of the second source gas into the processing chamber 201 can be started or stopped quickly by switching the valve.

<ALD-AlN process (S8)>
(Second source gas supply process)
Subsequently, the valve vb4 is closed and the valve vb3 is opened while the vacuum pump 264 is operated, and supply of the second source gas (Al source) into the processing chamber 201 is started. The second source gas is dispersed by the shower head 240 and is uniformly supplied onto the wafer 200 in the processing chamber 201. Excess second source gas flows through the exhaust duct 259 and is exhausted to the exhaust port 260 and the exhaust pipe 261 (second source gas supply step). At this time, since the processing temperature and the processing pressure are set to a processing temperature and a processing pressure at which the second source gas is not self-decomposed, the second source gas supplied onto the wafer 200 is adsorbed on the surface of the wafer 200. Precisely, gas molecules of the second source gas are adsorbed on the TiN film formed on the wafer 200 in the above-described CVD-TiN step (S6).

When the second source gas is supplied into the processing chamber 201, the second source gas is diffused in the processing chamber 201 so as to prevent the second source gas from entering the reaction gas supply pipe 213c. It is preferable to keep the valves vd1 and vd2 open so that the N ₂ gas always flows into the processing chamber 201 so as to facilitate the operation.

  After a predetermined time has elapsed after opening the valve vb3 and starting the supply of the second source gas, the valve vb3 is closed and the valve vb4 is opened to stop the supply of the second source gas into the processing chamber 201.

(Purge process)
After the valve vb3 is closed and the supply of the second source gas is stopped, the valves vd1, vd2, ve1, and ve2 are opened, and N ₂ gas is supplied into the processing chamber 201. The N ₂ gas is dispersed by the shower head 240 and supplied into the processing chamber 201, flows through the exhaust duct 259, and is exhausted to the exhaust port 260 and the exhaust pipe 261. Thereby, the second source gas remaining in the processing chamber 201 is removed, and the inside of the processing chamber 201 is purged with N ₂ gas (purge process).

(Reactive gas supply process)
When the purge in the processing chamber 201 is completed, the valves vc1 and vc2 are opened, and the supply of the reaction gas (NH ₃ gas) into the processing chamber 201 is started. The reaction gas is dispersed by the shower head 240 and is uniformly supplied onto the wafer 200 in the processing chamber 201, and reacts with the second source gas adsorbed on the surface of the wafer 200 to generate an AlN film on the wafer 200. To do. Precisely, it reacts with the gas molecules of the second source gas adsorbed on the TiN film formed on the wafer 200 in the above-mentioned CVD-TiN step (S6), and less than one atomic layer on the TiN film ( An AlN film having a thickness of less than 1 mm is generated. Excess reaction gas and reaction byproducts flow through the exhaust duct 259 and are exhausted to the exhaust port 260 and the exhaust pipe 261 (reaction gas supply step). Note that when the reaction gas is supplied into the process chamber 201, the reaction gas in the process chamber 201 is prevented from entering the first source gas supply pipe 213a and the second source gas supply pipe 213b. It is preferable to keep the valves ve1 and ve2 open so as to promote the diffusion of the gas, and to always allow the N ₂ gas to flow into the processing chamber 201.

  When a predetermined time elapses after the valves vc1 and vc2 are opened and the supply of the reaction gas is started, the valves vc1 and vc2 are closed and the supply of the reaction gas into the processing chamber 201 is stopped.

(Purge process)
After the valves vc 1 and vc 2 are closed and the supply of the reaction gas is stopped, the valves vd 1, vd 2, ve 1 and ve 2 are opened, and N ₂ gas is supplied into the processing chamber 201. The N ₂ gas is dispersed by the shower head 240 and supplied into the processing chamber 201, flows through the exhaust duct 259, and is exhausted to the exhaust port 260 and the exhaust pipe 261. Thus, the reaction gas and reaction by-products remaining in the processing chamber 201 are removed, and the inside of the processing chamber 201 is purged with N ₂ gas (purge process).

(Cycle processing)
The above-mentioned CVD-TiN process (the above-described CVD-TiN process (n cycles)) is performed by setting the above-described second source gas supply process, purge process, reaction gas supply process, and purge process as one cycle. In S6), an AlN film having a desired thickness is formed on the TiN film formed on the wafer 200. Note that after the ALD-AlN step (S8), the valves vb1 and vb2 are closed to stop the supply of the carrier gas to the second bubbler 220b.

  In the ALD-AlN step (S8), in preparation for the next CVD-TiN step (S6), the first source gas is vaporized to generate (preliminarily vaporize) the first source gas. That is, by opening the valves va1 and va2 and supplying the carrier gas whose flow rate is controlled by the MFC 222a from the first carrier gas supply pipe 237a into the first bubbler 220a, the first raw material contained in the first bubbler 220a is supplied. Vaporization is performed to generate the first source gas (preliminary vaporization step). In this preliminary vaporization step, while the vacuum pump 264 is operated, the valve va4 is opened while the valve va3 is closed, thereby bypassing the processing chamber 201 and exhausting it without supplying the first source gas into the processing chamber 201. Keep it.

<Repetition step (S10)>
By repeating the above-described CVD-TiN process (S6) and ALD-AlN process (S8) alternately a predetermined number of times (m times), a titanium nitride film (CVD-TiN film) by CVD and an ALD are formed on the wafer 200. And an aluminum nitride film (ALD-AlN film) are alternately laminated to form an aluminum titanium nitride film (TiAlN film) as a metal composite film having a desired film thickness.

<Substrate unloading step (S11)>
Thereafter, the wafer 200 after the TiAlN film having a desired film thickness is formed from the inside of the processing chamber 201 by a procedure opposite to the procedure shown in the substrate loading step (S1) and the substrate placing step (S2). Then, the substrate processing step according to the present embodiment is completed.

In addition, as processing conditions of the wafer 200 in the CVD-TiN process (S6) in this embodiment,
Treatment temperature: 250-450 ° C, preferably 350-450 ° C
Processing pressure: 30 to 266 Pa, preferably 30 to 100 Pa,
First raw material (TDMAT) supply flow rate: 10 to 100 sccm,
Film thickness (TiN): 1 to 5 nm,
Is exemplified.

In addition, as processing conditions of the wafer 200 in the ALD-AlN process (S8) in the present embodiment,
Treatment temperature: 250-450 ° C, preferably 350-450 ° C
Processing pressure: 30 to 266 Pa, preferably 30 to 100 Pa,
Second raw material (TMA) supply flow rate: 10 to 100 sccm,
Reaction gas (NH ₃ ) supply flow rate: 50 to 500 sccm,
Film thickness (AlN): 1 to 5 nm
Is exemplified.
In addition, 10-30 nm is illustrated as a film thickness of the total film thickness formed by the repeating process (S10), ie, the film thickness of a TiAlN film | membrane.

  Note that if the processing temperature is less than 250 ° C., the film formation reaction by CVD does not occur in the CVD-TiN step (S6). On the other hand, when the processing temperature exceeds 450 ° C., the film formation rate increases explosively in the CVD-TiN step (S6), making it difficult to control the film thickness. Therefore, in the CVD-TiN step (S6), in order to cause a film formation reaction by CVD and to control the film thickness, it is necessary to set the processing temperature to 250 ° C. or higher and 450 ° C. or lower. Note that it is preferable that the treatment temperature be 350 ° C. or higher because impurities in the film are reduced and resistivity is reduced.

  In the present embodiment, it is preferable to perform the CVD-TiN step (S6) and the ALD-AlN step (S8) at the same processing temperature and / or the same processing pressure. That is, in this embodiment, it is preferable to perform the CVD-TiN step (S6) and the ALD-AlN step (S8) at a constant processing temperature and / or a constant processing pressure. If the processing temperature and the processing pressure are set to predetermined values within the above-described exemplary ranges, the film formation by the CVD method and the film formation by the ALD method can be realized in the same condition. In this case, when changing from the CVD-TiN step (S6) to the ALD-AlN step (S8), and when changing from the ALD-AlN step (S8) to the CVD-TiN step (S6), the processing temperature changing step The process pressure changing step is unnecessary, and the throughput can be improved.

(3) Effects According to the Embodiment According to the present embodiment, the first metal film (TiN film) serving as the base (base) of the metal composite film (TiAlN film) is formed by the CVD method. The total film formation rate can be improved as compared with the case where the film is formed only by the ALD method, and the throughput can be improved. In addition, according to the present embodiment, when the second metal film (AlN film) is formed by the ALD method, the first metal film (TiN film) is formed as a base, so that the raw material for the base is Adsorption is promoted, and the deposition rate can be improved as compared with the case where the insulating film (HfSiON, SiO ₂ ) is used as a base, and the throughput can be improved. In the case of gate application, the film formed first and / or last is preferably an AlN film for reasons described later.

  Further, according to the present embodiment, it is possible to control the metal composition in the metal composite film (TiAlN film) by changing the ALD cycle of the second metal film (AlN film) by the ALD method. For example, by fixing the film thickness of the first metal film (TiN film) by the CVD method and changing the number of ALD cycles of the second metal film (AlN film) by the ALD method, the second in the metal composite film. It is possible to control the composition, that is, the concentration of the metal atoms (Al). It is also possible to change the composition profile in the depth direction of the metal composite film by changing the number of ALD cycles of the second metal film (AlN film) by the ALD method.

  Further, according to the present embodiment, the formation of the first metal film (TiN film) by the CVD method and the formation of the second metal film (AlN film) by the ALD method are not performed simultaneously but separately. It is said. In the CVD-TiN process (S6), a purge process is performed after the first source gas supply process to reliably replace the gas in the processing chamber 201. In the ALD-AlN process (S8), purge is performed at the end of the cycle process, and the gas in the process chamber 201 is surely replaced. As a result, the first source gas and the second source gas are not mixed in the processing chamber 201, and generation of particles due to a gas phase reaction between the first source gas and the second source gas in the processing chamber 201 can be suppressed. The film thickness uniformity and composition uniformity of the metal composite film (TiAlN film) can be improved. If the formation of the first metal film (TiN film) by the CVD method and the formation of the second metal film (AlN film) by the ALD method are performed simultaneously, the first source gas and the second source gas Therefore, it is necessary to consider the mixing time and reaction, and film thickness control and composition control become difficult. In addition, depending on the combination of gas species, particles are generated by a gas phase reaction between the first source gas and the second source gas, and the film thickness uniformity and composition uniformity of the metal composite film (TiAlN film) are deteriorated. There is a case.

  According to the present embodiment, since the first metal film (TiN film) formed by the CVD method uses a relatively high temperature process, ALD in the formation of the second metal film (AlN film) is used. A precursor having a relatively high decomposition temperature is selected. That is, CVD / ALD is performed at a high temperature, and it is possible to reduce residual impurities in the film by heat without using a damage source such as plasma (non-plasma).

  Further, according to the present embodiment, the amount of the precursor used can be reduced as compared with the conventional technique in which the film is formed only by the ALD method, and there is an advantage in cost.

<Other embodiments of the present invention>
In the above-described embodiment, the example in which the liquid raw material accommodated in the bubbler is vaporized by bubbling has been described. However, the liquid raw material may be vaporized using a vaporizer instead of the bubbler.

In the above embodiments, an example has been described using TDMAT as Ti raw material in CVD-TiN step, it may be used Ti raw material such as TiCl ₄ instead of TDMAT. In the above embodiments, an example has been described for supplying Ti raw material alone to the wafer in the CVD-TiN step, it may be supplied to the reaction gas such as NH ₃ or H ₂ at the same time.

In the above embodiments, an example has been described using TMA as Al raw material in ALD-AlN step, it may be used Al raw materials such as AlCl _3, instead of TMA. In the above-described embodiment, an example in which NH ₃ is used as a reaction gas in the ALD-AlN process has been described, but a gas such as H ₂ may be used instead of NH ₃ . In the ALD-AlN process, the number of ALD cycles may be changed. By changing the number of ALD cycles, the composition or concentration of Al in the metal composite film can be controlled. In the ALD-AlN process, the number of ALD cycles may be changed each time the CVD-TiN process and the ALD-AlN process are repeated. Thus, by changing the number of ALD cycles, the Al composition profile in the depth direction in the metal composite film can be controlled.

  Moreover, although the case where the TiAlN film is formed has been described in the above-described embodiment, the present invention is not limited to such a form, and can be applied to the film formation of RuAlN, TaAlN, MoAlN, NiAlN, CoAlN, or the like.

Example 1
As Example 1 of the present invention, film formation rate evaluation of CVD-TiN film formation and ALD-AlN film formation will be described. FIG. 6A is a diagram showing the TDMAT supply time dependence of the CVD-TiN film thickness on HfSiON, AlN, and SiO ₂ in CVD-TiN film formation. In FIG. 6A, the horizontal axis indicates the TDMAT supply time, and the vertical axis indicates the TiN film thickness. FIG. 6B is a diagram showing the ALD cycle number dependence of the ALD-AlN film thickness on HfSiON, TiN, and SiO ₂ in ALD-AlN film formation. In FIG. 6B, the horizontal axis indicates the number of ALD-AlN cycles, and the vertical axis indicates the AlN film thickness. Note that the CVD-TiN film formation and the ALD-AlN film formation in this evaluation were both performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment.

FIG. 6A shows that in the case of CVD-TiN film formation, the film formation rate hardly changes on HfSiON, AlN, and SiO ₂ . That is, it can be seen that the deposition rate in CVD-TiN deposition hardly depends on the underlying film. On the other hand, from FIG. 6B, in the case of ALD-AlN film formation, the film formation speed on TiN is significantly increased compared to the relatively low film formation speed on the insulating films HfSiON and SiO _2. I understand that That is, it can be seen that the film formation rate in ALD-AlN film formation largely depends on the underlying film. This is presumably because the amount of adsorption of the precursor changes in an extremely thin region (ultra thin film region). FIG. 6B shows that the film formation rate can be significantly increased by performing ALD-AlN film formation using TiN as a base.

  In the case of gate use, as will be described later, the first film (first layer) is preferably AlN. In that case, since the foundation is not TiN for the first layer, the above-described effects cannot be obtained. However, since ALD-AlN film formation is performed with TiN as a base after that, the film formation speed can be significantly increased even in this case.

(Example 2)
As Example 2 of the present invention, film formation evaluation (cross-sectional TEM photograph analysis) of a laminated film by repeating CVD-TiN film formation and ALD-AlN film formation will be described. In FIG. 7A, ALD-AlN film formation and CVD-TiN film formation are repeated, and a laminated film consisting of five layers (TiAlN 5 layer), a laminated film consisting of 11 layers (TiAlN 11 layer), and 21 layers. Each cross-sectional TEM photograph after forming a laminated film (TiAlN 21 layer) is shown. In FIG. 7B, ALD-AlN film formation and CVD-TiN film formation are repeated, and a laminated film consisting of 5 layers (TiAlN 5 layer), a laminated film consisting of 11 layers (TiAlN 11 layer), 21 forming a multilayer film comprising a layer (TiAlN 21 layer), after the N ₂ annealing at 900 ° C., respectively show cross-sectional TEM photograph. Note that the CVD-TiN film formation and the ALD-AlN film formation in this evaluation were both performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment. In any case, when forming the laminated film, an AlN layer was formed first and last. That is, the lowermost layer and the uppermost layer of the laminated film were AlN layers. The target film thickness of the laminated film was set to about 20 nm to 22 nm.

7 (a) and 7 (b), in the laminated film consisting of 11 layers (TiAlN 11 layer) and the laminated film consisting of 21 layers (TiAlN 21 layer), the TiN layer regardless of whether N ₂ annealing is performed or not. It can be seen that the boundary between the AlN layer becomes unclear. In the laminated film (TiAlN 21 layer) composed of 21 layers, the boundary between the TiN layer and the AlN layer can hardly be discriminated regardless of whether or not N ₂ annealing is performed, and it can be said that the appearance is equivalent to that of a single TiAlN film. That is, even when a film with the same thickness is formed, the boundary between the TiN layer and the AlN layer becomes less as the number of layers in the laminated film increases (the more the number of repetitions of CVD-TiN film formation and ALD-AlN film formation increases). It becomes clear (each layer is mixed), and it can be seen that it approaches a single layer of TiAlN film. In addition, when the case where N ₂ annealing is performed and the case where it is not performed are compared, it can be confirmed that there is almost no difference in the laminated film and that no film peeling occurs in any case.

(Example 3)
As Example 3 of the present invention, film formation evaluation (XPS depth direction profile analysis) of a laminated film by repeating CVD-TiN film formation and ALD-AlN film formation will be described. FIG. 8A shows an XPS depth profile after forming a laminated film (TIALN 11 LAYER) composed of 11 layers (22 nm) (TIN: 2NM, ALN: 2NM) and performing N ₂ annealing at 900 ° C. FIG. 8B shows a laminated film (TiAlN 21 layer) composed of 21 layers (21 nm) (TiN: 1 nm, AlN: 1 nm) and N ₂ annealed at 900 ° C. It is a figure which shows the XPS depth direction profile. In each figure, the horizontal axis indicates the sputtering time (synonymous with the depth direction), and the vertical axis indicates the concentration of each atom in the film. Note that the CVD-TiN film formation and the ALD-AlN film formation in this evaluation were both performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment. In any case, when forming the laminated film, an AlN layer was formed first and last. That is, the lowermost layer and the uppermost layer of the laminated film were AlN layers.

From FIG. 8A and FIG. 8B, the carbon (C) concentration in the TiAlN film is obtained by forming a laminated film (TiAlN 11 layer) consisting of 11 layers from the XPS depth profile analysis at 900 ° C. If you have made N ₂ annealing below 10 atom%, to form a laminated film composed of 21 layers (TiAlN 21 layer), it can be seen less than 5 atom% in the case of performing the _{N 2} annealing at 900 ° C..

Example 4
As a fourth embodiment of the present invention, description will be given of film formation evaluation (Al concentration control and resistivity analysis in a TiAlN film) by repeating CVD-TiN film formation and ALD-AlN film formation. FIG. 9A is a diagram showing the ALD-ALN cycle number dependence of the Al / Ti concentration in a TiAlN film composed of 11 layers. In FIG. 9A, the horizontal axis indicates the number of ALD-AlN cycles, the left vertical axis indicates the Al concentration, and the right vertical axis indicates the Ti concentration. FIG. 9B is a diagram showing the Al concentration dependence of the resistivity. In FIG. 9B, the horizontal axis indicates the Al concentration, and the vertical axis indicates the resistivity. Note that the CVD-TiN film formation and the ALD-AlN film formation in this evaluation were both performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment. In any case, when forming the laminated film, an AlN layer was formed first and last. That is, the lowermost layer and the uppermost layer of the laminated film were AlN layers. The film thickness of TiN was fixed at 2 nm, and the film thickness of AlN was changed by changing the number of ALD-AlN cycles.

  FIG. 9A shows that the Al concentration in the TiAlN film can be controlled to about 35 atom% by changing the number of ALD-AlN cycles. Further, FIG. 9B shows that the resistivity of the TiAlN film tends to increase as the Al concentration increases.

(Example 5)
As Example 5 of the present invention, film formation evaluation (TEM / SEM / AFM analysis) of a laminated film by repeating CVD-TiN film formation and ALD-AlN film formation will be described. FIG. 10A shows an SEM photograph after forming a TiAlN film by repeating CVD-TiN film formation and ALD-AlN film formation and performing N ₂ annealing at 900 ° C. FIG. FIG. 10B shows a cross-sectional TEM photograph after forming a TiAlN film by repeating CVD-TiN film formation and ALD-AlN film formation and performing N ₂ annealing at 900 ° C. FIG. 10C shows an AFM photograph after forming a TiAlN film by repeating CVD-TiN film formation and ALD-AlN film formation and performing N ₂ annealing at 900 ° C. In each case, the TiAlN film was composed of a laminated film of 21 layers (21 nm) (TiN: 1 nm, AlN: 1 nm). Note that the CVD-TiN film formation and the ALD-AlN film formation in this evaluation were both performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment. In any case, when forming the laminated film, an AlN layer was formed first and last. That is, the lowermost layer and the uppermost layer of the laminated film were AlN layers.

  10 (a), 10 (b), and 10 (c), it can be seen that the TiAlN film does not have grain condensation and film peeling. Moreover, it turns out that the surface of these films | membranes is comparatively smooth (RMS = 1.0nm).

(Example 6)
As Example 6 of the present invention, pMOS application evaluation in which a TiAlN film formed by repeating CVD-TiN film formation and ALD-AlN film formation is applied to a gate electrode of a pMOS will be described. FIG. 11A shows an evaluation sample structure, which shows a gate structure of a p-MOSFET in which a TiAlN film formed by repeating CVD-TiN film formation and ALD-AlN film formation is applied to a gate electrode. Specifically, an SiON film is formed as an interface layer on a silicon wafer, an HfSiON film is formed thereon as a high dielectric constant gate insulating film, and a TiAlN film and a WW film are further formed thereon as a metal gate electrode by the above-described method. A structure in which a film is formed is shown (W / TiAlN / Hf (Al) SiON / SiON / Si wafer). In the figure, Hf (Al) SiON indicates that Al in the TiAlN film is mixed into the HfSiON film due to this structure. As the interface layer, a SiO ₂ film may be used instead of the SiON film. FIG. 11B shows ALD-TiAlN, that is, a condition and a laminated structure when a TiAlN film is formed by repeating CVD-TiN film formation and ALD-AlN film formation. FIG. 11C is a diagram showing the Al concentration dependency of the effective work function in the TiAlN film. In FIG. 11C, the horizontal axis represents the Al concentration in TiAlN, the left vertical axis represents the effective work function, and the right vertical axis represents EOT. In the figure, ◯ and □ indicate the effective work function and EOT, respectively. In this evaluation, three types of samples were prepared in which the Al concentration in the TiAlN film was changed to 10%, 20%, and 30%. Moreover, both CVD-TiN film formation and ALD-AlN film formation in this evaluation were performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment. Further, the TiAlN film was composed of 21 laminated films, and in each case, when forming the laminated film, the AlN layer was formed first and last. That is, the lowermost layer and the uppermost layer of the laminated film were AlN layers. In addition, the effective work function indicates data after activation annealing (Spike) at 1000 ° C.

  FIG. 11C shows that the effective work function is improved to 4.8 eV by using the TiAlN film (Al concentration: 30%) in this example as the metal gate electrode.

(Example 7)
As Example 7 of the present invention, pMOS application evaluation in which a TiAlN film formed by repeated CVD-TiN film formation and ALD-AlN film formation is applied to a gate electrode of a pMOS will be described. In this evaluation, when the TiAlN film is formed, an ALD-AlN film is first formed on the high dielectric constant gate insulating film (AlN first) and a CVD-TiN film is formed first (TiN). First) and effective work function and EOT were compared.

FIGS. 12A and 13A show an evaluation sample structure. The gate of a p-MOSFET in which a TiAlN film formed by repeating CVD-TiN film formation and ALD-AlN film formation is applied to a gate electrode. The structure is shown. Specifically, an SiON film is formed as an interface layer on a silicon wafer, an HfSiON film is formed thereon as a high dielectric constant gate insulating film, and a TiAlN film and a WW film are further formed thereon as a metal gate electrode by the above-described method. A structure in which a film is formed is shown (W / TiAlN / HfSiON / SiON / Si wafer). Note that the concentration of Hf in the TiAlN film was 75%. As the interface layer, a SiO ₂ film may be used instead of the SiON film.

  FIG. 12B and FIG. 13B show ALD-TiAlN according to the present embodiment, that is, a condition when a TiAlN film is formed by repeating CVD-TiN film formation and ALD-AlN film formation, and a laminated structure thereof. Is shown. Note that the TiAlN film shown in FIG. 12B was formed by first forming an ALD-AlN film and alternately laminating 11 layers of CVD-TiN films and ALD-AlN films. That is, the lowermost layer and the uppermost layer of the laminated film were each an AlN layer. The film thickness of the uppermost AlN layer was 3 nm. The TiAlN film shown in FIG. 13B was formed by first forming an ALD-AlN film and alternately laminating 21 layers of CVD-TiN films and ALD-AlN films. That is, the lowermost layer and the uppermost layer of the laminated film were each an AlN layer. The film thickness of the uppermost AlN layer was 3 nm.

  12 (c) and 13 (c) show ALD-TiAlN according to the comparative example, that is, conditions and a laminated structure when forming a TiAlN film by repeating CVD-TiN film formation and ALD-AlN film formation. Show. Note that the TiAlN film shown in FIG. 12C was formed by first forming a CVD-TiN film and alternately laminating 10 layers of CVD-TiN films and ALD-AlN films. That is, the lowermost layer of the laminated film was a TiN layer, and the uppermost layer was an AlN layer. The film thickness of the uppermost AlN layer was 3 nm. The TiAlN film shown in FIG. 13C was formed by first forming a CVD-TiN film and alternately stacking 20 layers of CVD-TiN films and ALD-AlN films. That is, the lowermost layer of the laminated film was a TiN layer, and the uppermost layer was an AlN layer. The film thickness of the uppermost AlN layer was 3 nm.

  FIG. 12D and FIG. 13D are diagrams showing the dependency of the effective work function on the Al concentration in the TiAlN film. In FIGS. 12D and 13D, the horizontal axis represents the Al concentration in TiAlN, the left vertical axis represents the effective work function, and the right vertical axis represents EOT. In the figure, ◯ and □ indicate the effective work function and EOT when the ALD-AlN film is formed first, and ● and ■ indicate the effective work function and EOT when the CVD-TiN film is formed first. Respectively. In this evaluation, three types of samples were prepared in which the Al concentration in the TiAlN film was changed to 10%, 20%, and 30%. Moreover, both CVD-TiN film formation and ALD-AlN film formation in this evaluation were performed by setting the processing conditions to values within the range of the processing conditions in the above-described embodiment. In addition, the effective work function indicates data after activation annealing (Spike) at 1000 ° C.

One of the purposes of using an ALD-TiAlN film as a gate electrode is to transfer Al from a TiAlN film to the interface between an interface layer such as a SiON film or SiO ₂ film and a high-k film (high dielectric constant film) such as an HfSiON film. It may diffuse efficiently and improve the effective work function of the gate electrode. From FIG. 12D and FIG. 13D, the improvement width of the effective work function varies depending on whether the ALD-AlN film is formed first or the CVD-TiN film is formed first. I understand. That is, when the ALD-AlN film is formed first, Al is likely to diffuse from the TiAlN film to the lower layer direction, and the improvement in effective work function is large in both the 11-layer and 21-layer samples. The improvement of 0.2 eV can be confirmed from .6 eV to 4.8 eV. On the other hand, when the CVD-TiN film is formed first, Al is difficult to diffuse, and it can be seen that the improvement in effective work function is small in both the 10-layer and 20-layer samples. This is partly because the TiN film formed first blocks Al diffusion from the TiAlN film in the lower layer direction (TiN acts as a diffusion blocking layer that blocks Al diffusion). it is conceivable that. In general, it is said that the improvement range of the effective work function by diffusing Al is about 0.2 eV, and when the ALD-AlN film is formed first, Al can be diffused more efficiently. It turns out that an effect is easy to be exhibited.

(Example 8)
As an eighth embodiment of the present invention, pMOS application evaluation in which a TiAlN film formed by repeated CVD-TiN film formation and ALD-AlN film formation is applied to a pMOS gate electrode will be described. In this evaluation, in the formation of the TiAlN film, the last CVD-TiN film was formed (TiN last), and the last ALD-AlN film was formed (AlN last), that is, the uppermost layer was CVD-TiN. The oxidation resistance characteristics of the TiAlN film were compared between the case where the film was used and the case where the uppermost layer was an ALD-AlN film.

  FIG. 14A is a diagram showing the change over time in the degree of oxidation of the TiAlN film in which the uppermost layer is a CVD-TiN film. In FIG. 14A, the horizontal axis indicates the exposure time of the TiAlN film after formation of the TiAlN film to the atmosphere, and the vertical axis indicates the electrical resistivity of the TiAlN film. In the figure, ◯ indicates the electrical resistivity of the CVD-TiN film. Note that an ALD-AlN film is not formed on the uppermost layer, and the Al content in the CVD-TiN film is 0%. In the figure, □ marks indicate the electrical resistivity of the TiAlN film formed by alternately repeating the film formation of the CVD-TiN film and the film formation of the ALD-AlN film, and the uppermost layer is a CVD-TiN film. . Each ALD-AlN film is formed through 18 ALD cycles, and the Al content in the TiAlN film is 30%. In the figure, Δ indicates the electrical resistivity of the TiAlN film formed by alternately repeating the deposition of the CVD-TiN film and the deposition of the ALD-AlN film, and the uppermost layer is a CVD-TiN film. . Each ALD-AlN film is formed through 9 ALD cycles, and the Al content in the TiAlN film is 20%. In the figure, ◇ indicates the electrical resistivity of a TiAlN film formed by alternately repeating the film formation of a CVD-TiN film and the film formation of an ALD-AlN film, and the uppermost layer is a CVD-TiN film. . Each ALD-AlN film is formed through four ALD cycles, and the Al content in the TiAlN film is 15%.

  FIG. 14B is a diagram showing the change over time in the degree of oxidation of the TiAlN film in which the uppermost layer is an ALD-AlN film. In FIG. 14B, the horizontal axis represents the exposure time of the TiAlN film to the atmosphere after the TiAlN film is formed, and the vertical axis represents the electrical resistivity of the TiAlN film. In the figure, the circles indicate the electrical resistivity of the TiAlN film formed by forming the ALD-AlN film as the uppermost layer after forming the CVD-TiN film. The uppermost ALD-AlN film is formed through 18 ALD cycles. In the figure, □ indicates the electrical resistivity of the TiAlN film formed by alternately repeating the CVD-TiN film formation and the ALD-AlN film formation, and the uppermost layer is an ALD-AlN film. . Each ALD-AlN film is formed through 18 ALD cycles, and the Al content in the TiAlN film is 30%. In the figure, Δ marks indicate the electrical resistivity of the TiAlN film formed by alternately repeating the film formation of the CVD-TiN film and the film formation of the ALD-AlN film, and the uppermost layer is an ALD-AlN film. . The uppermost ALD-AlN film is formed through 18 ALD cycles, and the lower ALD-AlN film is formed through 9 ALD cycles. The Al content is 20%. In the figure, ◇ indicates the electrical resistivity of the TiAlN film formed by alternately repeating the CVD-TiN film formation and the ALD-AlN film formation, and the uppermost layer is an ALD-AlN film. . The uppermost ALD-AlN film is formed through 18 ALD cycles, and the lower ALD-AlN film is formed through 4 ALD cycles, respectively, in the TiAlN film. The Al content is 15%.

From FIG. 14A, it can be seen that in the TiAlN film having the uppermost layer as the CVD-TiN film, the electrical resistivity increases with the passage of the exposure time to the atmosphere and is easily oxidized. On the other hand, from FIG. 14B, in the TiAlN film having the ALD-AlN film as the uppermost layer, the electrical resistivity hardly increases even when the exposure time to the atmosphere elapses, and is hardly oxidized. I understand that. This is considered to be due to the fact that the ALD-AlN film formed as the uppermost layer acts as an oxygen blocking layer that blocks the atmospheric oxygen from being taken into the CVD-TiN film. . Conversely, if the uppermost layer is a CVD-TiN film, oxygen in the atmosphere is likely to be taken into the CVD-TiN film and oxidation of the TiAlN film is likely to occur. If the gate electrode contains a large amount of oxygen, high-temperature heat treatment causes oxygen in the gate electrode to pass through the high-k film such as HfSiON and diffuse to the interface layer such as SiON and SiO _2. In some cases, the EOT increases and the scaling of the transistor may be hindered. However, by using an ALD-AlN film as the uppermost layer, such a problem can be solved.

<Another Embodiment of the Present Invention>
In the above-described embodiment, an example in which film formation is performed using a single-wafer type apparatus that processes one substrate at a time as the substrate processing apparatus has been described, but the present invention is not limited to the above-described embodiment. For example, the film may be formed using a batch type vertical apparatus that processes a plurality of substrates at once as the substrate processing apparatus.

  In the above-described embodiment, an example in which the CVD method and the ALD method are used together to improve the film forming speed and the reduction in throughput is described. However, if this batch type vertical apparatus is used, only the ALD method is used. Even in the case of film formation, the decrease in throughput can be eliminated by increasing the number of substrates processed at one time. Hereinafter, a method of forming a film only by the ALD method using this vertical apparatus, that is, a vertical ALD apparatus will be described.

  FIG. 15 is a schematic configuration diagram of a vertical processing furnace of a vertical ALD apparatus preferably used in the present embodiment. FIG. 15A shows a processing furnace 302 portion in a vertical cross section, and FIG. 15B shows a processing furnace. A portion 302 is shown in the cross-sectional view along the line AA in FIG.

  As shown in FIG. 15A, the processing furnace 302 has a heater 307 as a heating means (heating mechanism). The heater 307 has a cylindrical shape and is vertically installed by being supported by a heater base as a holding plate.

Inside the heater 307, a process tube 303 as a reaction tube is disposed concentrically with the heater 307. The process tube 303 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and has a cylindrical shape with the upper end closed and the lower end opened. A processing chamber 301 is formed in a cylindrical hollow portion of the process tube 303 so that wafers 200 as substrates can be accommodated in a state of being aligned in multiple stages in a vertical posture in a horizontal posture by a boat 317 described later.

  A manifold 309 is disposed below the process tube 303 concentrically with the process tube 303. The manifold 309 is made of, for example, stainless steel and is formed in a cylindrical shape with an upper end and a lower end opened. The manifold 309 is engaged with the process tube 303 and is provided to support the process tube 303. An O-ring 320a as a seal member is provided between the manifold 309 and the process tube 303. Since the manifold 309 is supported by the heater base, the process tube 303 is vertically installed. A reaction vessel is formed by the process tube 303 and the manifold 309.

  A first nozzle 333 a as a first gas introduction part and a second nozzle 333 b as a second gas introduction part are connected to the manifold 309 so as to penetrate the side wall of the manifold 309. Each of the first nozzle 333a and the second nozzle 333b has an L shape having a horizontal portion and a vertical portion, the horizontal portion is connected to the manifold 309, and the vertical portion is between the inner wall of the process tube 303 and the wafer 200. It is provided in an arc-shaped space so as to rise in the stacking direction of the wafer 200 along the inner wall above the lower part of the process tube 303. A first gas supply hole 348a and a second gas supply hole 348b, which are supply holes for supplying gas, are provided on the side surfaces of the vertical portions of the first nozzle 333a and the second nozzle 333b, respectively. The first gas supply hole 348a and the second gas supply hole 348b have the same opening area from the lower part to the upper part, and are provided at the same opening pitch.

  The gas supply system connected to the first nozzle 333a and the second nozzle 333b is the same as in the above-described embodiment. However, in the present embodiment, the first raw material gas supply system and the second raw material gas supply system are connected to the first nozzle 333a, and the reactive gas supply system is connected to the second nozzle 333b. Different. That is, in the present embodiment, the source gas (first source gas, second source gas) and the reaction gas are supplied by separate nozzles. In addition, you may make it supply each raw material gas with a separate nozzle.

  The manifold 309 is provided with an exhaust pipe 331 that exhausts the atmosphere in the processing chamber 301. A vacuum pump 346 as an evacuation device is connected to the exhaust pipe 331 through a pressure sensor 345 as a pressure detector and an APC (Auto Pressure Controller) valve 342 as a pressure regulator. By adjusting the APC valve 342 based on the detected pressure information, the processing chamber 301 is configured to be evacuated so that the pressure in the processing chamber 301 becomes a predetermined pressure (degree of vacuum). Note that the APC valve 342 is configured to open and close the valve to evacuate / stop evacuation in the processing chamber 301, and to adjust the valve opening to adjust the pressure in the processing chamber 301. Open / close valve.

  Below the manifold 309, a seal cap 319 is provided as a furnace port lid that can airtightly close the lower end opening of the manifold 309. The seal cap 319 is brought into contact with the lower end of the manifold 309 from the lower side in the vertical direction. The seal cap 319 is made of a metal such as stainless steel and is formed in a disk shape. On the upper surface of the seal cap 319, an O-ring 320b is provided as a seal member that contacts the lower end of the manifold 309. On the opposite side of the seal cap 319 from the processing chamber 301, a rotation mechanism 367 for rotating a boat 317 described later is installed. A rotation shaft 355 of the rotation mechanism 367 passes through the seal cap 319 and is connected to the boat 317, and is configured to rotate the wafer 200 by rotating the boat 317. The seal cap 319 is configured to be moved up and down in a vertical direction by a boat elevator 315 as an elevating mechanism disposed outside the process tube 303, and thereby the boat 317 is carried into and out of the processing chamber 301. It is possible.

  The boat 317 as a substrate holder is made of a heat-resistant material such as quartz or silicon carbide, and is configured to hold a plurality of wafers 200 in a horizontal posture and in a state where the centers are aligned with each other and held in multiple stages. Yes. A heat insulating member 318 made of a heat resistant material such as quartz or silicon carbide is provided at the lower part of the boat 317 so that heat from the heater 307 is not easily transmitted to the seal cap 319 side. A temperature sensor 363 as a temperature detector is installed in the process tube 303, and the temperature in the processing chamber 301 is adjusted by adjusting the power supply to the heater 307 based on the temperature information detected by the temperature sensor 363. Is configured to have a predetermined temperature distribution. The temperature sensor 363 is provided along the inner wall of the process tube 303, similarly to the first nozzle 333a and the second nozzle 333b.

  The controller 380 as a control unit (control means) includes an APC valve 342, a heater 307, a temperature sensor 363, a vacuum pump 346, a rotation mechanism 367, a boat elevator 315, valves va1 to va4, vb1 to vb4, vc1 to vc2, and vd1. The operation of vd2, ve1 to ve2, high durability high speed gas valve V, flow rate controllers 222a, 222b, 222c, 222d, 222e and the like is controlled.

Next, referring to FIG. 16, a substrate processing step of forming a thin film on the wafer 200 by the ALD method as one step of the manufacturing process of the semiconductor device using the processing furnace 302 of the vertical ALD apparatus according to the above configuration will be described. While explaining. Here, by alternately repeating the ALD-AlN process and the ALD-TiN process, a TiAlN film is formed on the wafer 200 on the surface of which the HfSiON film is formed via the SiON film. An example of forming an AlN film (AlN first) and finally forming an AlN film (AlN last) will be described. Here, TiCl ₄ , TMA, and NH ₃ are used as the first raw material, the second raw material, and the reaction gas, respectively. In the following description, the operation of each part constituting the vertical ALD apparatus is controlled by the controller 380.

  A plurality of wafers 200 are loaded into the boat 317 (wafer charge). Then, as shown in FIG. 15A, the boat 317 holding the plurality of wafers 200 is lifted by the boat elevator 315 and loaded into the processing chamber 301 (boat loading). In this state, the seal cap 319 is in a state of sealing the lower end of the manifold 309 via the O-ring 320b.

  The inside of the processing chamber 301 is evacuated by a vacuum pump 346 so that the inside of the processing chamber 301 has a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 301 is measured by the pressure sensor 345, and the APC valve 342 is feedback-controlled based on the measured pressure. In addition, heating is performed by the heater 307 so that the inside of the processing chamber 301 has a desired temperature. At this time, feedback control of the power supply to the heater 307 is performed based on the temperature information detected by the temperature sensor 363 so that the inside of the processing chamber 301 has a desired temperature distribution. Then, the wafer 200 is rotated by rotating the boat 317 by the rotation mechanism 367.

  Thereafter, the ALD-AlN process and the ALD-TiN process are alternately repeated a predetermined number of times to alternately stack the ALD-AlN film and the ALD-TiN film on the wafer 200 (HfSiON film). A TiAlN film is formed. At that time, an ALD-AlN film is first formed by performing an ALD-AlN process (AlN first). Further, the ALD-AlN process is finally performed to finally form an ALD-AlN film (AlN last). That is, the lowermost layer and the uppermost layer of the TiAlN film are both ALD-AlN films.

    In addition, the procedure of the ALD-AlN process is the same as the ALD-AlN process (S8) in the above-described embodiment. On the other hand, the procedure of the ALD-TiN process is different from the CVD-TiN process (S6) in the above-described embodiment. Hereinafter, the ALD-TiN process will be described.

(First source gas supply process)
In the ALD-TiN process, the valve va4 is closed and the valve va3 is opened while the vacuum pump 346 is operated, and the supply of the first source gas (Ti source) into the processing chamber 301 is started. The first source gas is uniformly supplied onto the wafer 200 in the processing chamber 301 through the first nozzle 333a. Excess first source gas is exhausted to the exhaust pipe 331 (first source gas supply step). At this time, since the processing temperature and the processing pressure are set to a processing temperature and processing pressure at which the first source gas is not self-decomposed, the first source gas is formed on the AlN film formed on the wafer 200 in the ALD-AlN process. Gas molecules are adsorbed. After the valve va3 is opened and the supply of the first source gas is started, the valve va3 is closed and the valve va4 is opened after a predetermined time has elapsed, and the supply of the first source gas into the processing chamber 301 is stopped. At the same time, the valves va1 and va2 are closed, and the supply of the carrier gas to the first bubbler 220a is also stopped.

(Purge process)
After the valve va3 is closed and the supply of the first source gas is stopped, the valves vd1, vd2, ve1, and ve2 are opened, and N ₂ gas is supplied into the processing chamber 301. The N ₂ gas is supplied into the processing chamber 301 through the first nozzle 333a and the second nozzle 333b and is exhausted to the exhaust pipe 331. Thereby, the first source gas remaining in the processing chamber 301 is removed, and the inside of the processing chamber 301 is purged with N ₂ gas.

(Reactive gas supply process)
When the purge in the processing chamber 301 is completed, the valves vc1 and vc2 are opened, and the supply of the reaction gas (NH ₃ gas) into the processing chamber 301 is started. The reaction gas is uniformly supplied onto the wafer 200 in the processing chamber 301 through the second nozzle 333b, and the first source gas adsorbed on the AlN film formed on the wafer 200 in the ALD-AlN process. It reacts with gas molecules to produce a TiN film of less than 1 atomic layer (less than 1 cm) on the AlN film. Excess reaction gas and reaction byproducts are exhausted to the exhaust pipe 331 (reaction gas supply step). After the valves vc1 and vc2 are opened and the supply of the reaction gas is started, the valves vc1 and vc2 are closed when a predetermined time has elapsed, and the supply of the reaction gas into the processing chamber 301 is stopped.

(Purge process)
After the valves vc 1 and vc 2 are closed and the supply of the reaction gas is stopped, the valves vd 1, vd 2, ve 1 and ve 2 are opened, and N ₂ gas is supplied into the processing chamber 301. The N ₂ gas is supplied into the processing chamber 301 through the first nozzle 333a and the second nozzle 333b and is exhausted to the exhaust pipe 331. As a result, the reaction gas and reaction by-products remaining in the processing chamber 301 are removed, and the processing chamber 301 is purged with N ₂ gas.

(Cycle processing)
The above first source gas supply process, purge process, reaction gas supply process, and purge process are taken as one cycle, and the ALD-AlN process performs wafer processing in a predetermined number of times (n ′ cycles). A TiN film having a desired thickness is formed on the TiN film formed on 200.

  After a TiAlN film having a predetermined thickness is formed on the wafer 200 (HfSiON film) by alternately repeating the ALD-AlN process and the ALD-TiN process a predetermined number of times, the seal cap 319 is lowered by the boat elevator 315. The lower end of the manifold 309 is opened, and the wafer 200 after the TiAlN film having a predetermined thickness is formed is unloaded from the lower end of the manifold 309 to the outside of the process tube 303 while being held by the boat 317 (boat unloading). ) Thereafter, the processed wafer 200 is taken out from the boat 317 (wafer discharge).

    In the present embodiment, a TiAlN film is formed on the wafer 200 by alternately repeating an ALD-AlN process and an ALD-TiN process using a vertical ALD apparatus. Although an example in which an AlN film is formed has been described above, the present invention is not limited to this embodiment. For example, using a vertical ALD apparatus, a TiAlN film is formed on the wafer 200 by alternately repeating an ALD-AlN process and a CVD-TiN process. At that time, an AlN film is formed first and last. You may make it do. In this case, the film formation rate can be improved as compared with the case where the film is formed only by the ALD method, and the throughput can be further improved.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

  According to one aspect of the present invention, an insulating film is formed on a substrate, a high dielectric constant insulating film is formed on the insulating film, and an aluminum titanium nitride film is formed on the high dielectric constant insulating film. In the step of forming the aluminum titanium nitride film, the formation of the aluminum nitride film and the formation of the titanium nitride film are alternately repeated. At this time, the nitridation is performed first and / or last. A method of manufacturing a semiconductor device for forming an aluminum film is provided.

  Preferably, the aluminum nitride film is formed by an ALD method, the titanium nitride film is formed by an ALD method or a CVD method, and the formation of the aluminum nitride film and the formation of the titanium nitride film are performed in the same processing chamber. The substrate temperature is set to the same temperature.

  Preferably, the aluminum nitride film is formed by repeating the cycle a plurality of times, wherein the step of supplying a raw material containing aluminum atoms and the step of supplying a gas containing nitrogen atoms are defined as one cycle. The concentration of aluminum atoms in the aluminum titanium nitride film is controlled by changing the number of times.

  Preferably, the insulating film is a silicon oxide film or a silicon oxynitride film, and the high dielectric constant insulating film is a hafnium silicate film.

  According to another aspect of the present invention, an insulating film is formed on a substrate, a high dielectric constant insulating film is formed on the insulating film, and an aluminum titanium nitride film is formed on the high dielectric constant insulating film. Forming the aluminum titanium nitride film, and forming the aluminum nitride film by the ALD method and forming the titanium nitride film by the CVD method in the same processing chamber. Provided is a method of manufacturing a semiconductor device in which the aluminum nitride film is formed at the beginning and / or at the end, alternately and repeatedly with the temperature set at the same temperature, with the purge in the processing chamber interposed therebetween. The

  Preferably, the formation of the aluminum nitride film and the formation of the titanium nitride film are performed in a state where the pressure in the processing chamber is set to the same pressure.

  Preferably, the aluminum nitride film is formed by repeating the cycle a plurality of times, wherein the step of supplying a raw material containing aluminum atoms and the step of supplying a gas containing nitrogen atoms are defined as one cycle. The concentration of aluminum atoms in the aluminum titanium nitride film is controlled by changing the number of times.

  Preferably, the insulating film is a silicon oxide film or a silicon oxynitride film, and the high dielectric constant insulating film is a hafnium silicate film.

  According to still another aspect of the present invention, there is provided a processing chamber for processing a substrate having a high dielectric constant insulating film formed on the surface via an insulating film, and a first raw material containing aluminum atoms is supplied into the processing chamber. A raw material supply system, a second raw material supply system for supplying a second raw material containing titanium atoms into the processing chamber, a reactive gas supply system for supplying a reactive gas containing nitrogen atoms into the processing chamber, A heater for heating a substrate; formation of an aluminum nitride film by supplying the first raw material and the reactive gas into the processing chamber; and forming a titanium nitride film by supplying the second raw material and the reactive gas into the processing chamber. The aluminum nitride titanium film is formed on the high dielectric constant insulating film formed on the substrate by alternately and repeatedly forming the aluminum nitride film. So as to form a um membrane, the first raw material supply system, said second source supply system, the reactive gas supply system, and a substrate processing apparatus is provided with a controller for controlling the heater.

According to yet another aspect of the invention,
An insulating film formed on the substrate;
A high dielectric constant insulating film formed on the insulating film;
An aluminum titanium nitride film formed on the high dielectric constant insulating film,
The aluminum titanium nitride film is composed of a laminated film of an aluminum nitride film and a titanium nitride film, and a semiconductor device is provided in which the lowermost layer and / or the uppermost layer of the aluminum titanium nitride film is the aluminum nitride film. The

  According to one embodiment of the present invention, a step of forming a first metal film including a first metal atom on a substrate by a CVD method, and a second step including a second metal atom on the substrate by an ALD method. By alternately repeating the step of forming the metal film, there is provided a method of manufacturing a semiconductor device that forms the third metal film containing the first metal atom and the second metal atom.

  Preferably, the step of forming the first metal film and the step of forming the second metal film are continuously performed in the same processing chamber.

  Preferably, the step of forming the first metal film and the step of forming the second metal film are performed at the same processing temperature and / or the same processing pressure.

  Preferably, in the step of forming the first metal film, a first raw material containing the first metal atom is supplied to the substrate, and in the step of forming the second metal film, the substrate is formed. The process of supplying the second raw material containing the second metal atom and the process of supplying the reaction gas to the substrate are defined as one cycle, and this cycle is repeated a plurality of times.

  Preferably, the concentration of the second metal atom in the third metal film is controlled by changing the number of cycles in the step of forming the second metal film.

  Preferably, the first metal atom is a titanium atom (Ti), and the second metal atom is an aluminum atom (Al).

  Preferably, the first metal film is a titanium nitride film (TiN film), the second metal film is an aluminum nitride film (AlN), and the third metal film is an aluminum titanium nitride film (TiAlN). Membrane).

  According to another aspect of the present invention, a processing chamber for processing a substrate, a first raw material supply system for supplying a first raw material containing a first metal atom in the processing chamber, and a second metal in the processing chamber. A second raw material supply system for supplying a second raw material containing atoms; a reactive gas supply system for supplying a reactive gas into the processing chamber; a heater for heating a substrate in the processing chamber; and the first raw material in the processing chamber. To form a first metal film containing the first metal atoms on the substrate by a CVD method, and alternately supply the second raw material and the reaction gas into the processing chamber. Then, a second metal film containing the second metal atom is formed by ALD, and the third metal film containing the first metal atom and the second metal atom is formed by repeating this alternately. To form the first raw material supply system, the front The second raw material supply system, the reactive gas supply system, and a substrate processing apparatus is provided with a controller for controlling the heater.

200 wafer (substrate)
201 processing chamber 202 processing vessel 203 support stand 206 heater 213a first source gas supply pipe 213b second source gas supply pipe 213c reaction gas supply pipe 213d purge gas supply pipe 213e purge gas supply pipe 237a first carrier gas supply pipe 237b second carrier gas Supply pipe 220a First bubbler 220b Second bubbler 280 Controller

Claims (8)

  The aluminum nitride film and the titanium nitride film are formed on the high dielectric constant insulating film formed on the substrate through the insulating film by alternately and repeatedly forming the aluminum nitride film and the titanium nitride film. A method of manufacturing a semiconductor device in which the aluminum nitride film is first formed in the step of forming the stacked film.   The method for manufacturing a semiconductor device according to claim 1, wherein in the step of forming the laminated film, the aluminum nitride film is formed first and last.   The method for manufacturing a semiconductor device according to claim 1, wherein the formation of the aluminum nitride film and the formation of the titanium nitride film are performed in the same processing chamber with the temperature of the substrate set to the same temperature. The aluminum nitride film is formed by repeating this cycle a plurality of times, with the step of supplying a raw material containing aluminum atoms and the step of supplying a gas containing nitrogen atoms as one cycle.
4. The titanium nitride film according to claim 1, wherein the titanium nitride film is formed by repeating the cycle a plurality of times, with the step of supplying a raw material containing titanium atoms and the step of supplying a gas containing nitrogen atoms being one cycle. A method for manufacturing the semiconductor device according to claim 1.   The aluminum nitride film is formed by repeating this cycle a plurality of times, with the step of supplying the raw material containing aluminum atoms and the step of supplying the gas containing nitrogen atoms as one cycle, and the number of cycles is changed. 5. The method of manufacturing a semiconductor device according to claim 1, wherein the concentration of aluminum atoms in the stacked film is controlled.   The aluminum nitride film and the titanium nitride film are formed on the high dielectric constant insulating film formed on the substrate through the insulating film by alternately and repeatedly forming the aluminum nitride film and the titanium nitride film. And a substrate processing method in which the aluminum nitride film is first formed in the step of forming the stacked film. A processing chamber for processing a substrate having a high dielectric constant insulating film formed on the surface via an insulating film;
A first raw material supply system for supplying a first raw material containing aluminum atoms into the processing chamber;
A second raw material supply system for supplying a second raw material containing titanium atoms into the processing chamber;
A reaction gas supply system for supplying a reaction gas containing nitrogen atoms into the processing chamber;
A heater for heating the substrate in the processing chamber;
The formation of an aluminum nitride film by supplying the first raw material and the reactive gas into the processing chamber and the formation of a titanium nitride film by supplying the second raw material and the reactive gas into the processing chamber are alternately repeated. And performing a process of forming a laminated film in which the aluminum nitride film and the titanium nitride film are alternately laminated on the high dielectric constant insulating film formed on the substrate via the insulating film. In the process of forming the laminated film, the first raw material supply system, the second raw material supply system, the reactive gas supply system, and the heater are controlled so as to form the aluminum nitride film first. A controller,
A substrate processing apparatus. An insulating film formed on the substrate;
A high dielectric constant insulating film formed on the insulating film;
A laminated film in which aluminum nitride films and titanium nitride films are alternately laminated, formed on the high dielectric constant insulating film;
A semiconductor device in which a lowermost layer of the laminated film is the aluminum nitride film.