KR101533846B1 - Semiconductor device manufacturing apparatus and method - Google Patents

Abstract

A semiconductor device manufacturing apparatus for forming an alumina film containing? -Alumina on a substrate W for manufacturing a semiconductor device is characterized in that the processing atmosphere in the reaction vessel 2 is heated to 800 占 폚 or higher and 1,000 占 폚 or lower The raw gas and the gas are supplied into the reaction vessel 2 from the gas supply holes 311 of the first gas supply system 31 and the gas supply holes 341 of the second gas supply system 34, An alumina film is formed on the surface of each substrate W by supplying oxidizing gas at the same time and reacting. The gas supply holes 311 and 341 of the first gas supply system 31 and the gas supply system 34 of the second gas supply system 34 are arranged in such a manner that the gas supply holes 311 and 341 of the first gas supply system 31, And is provided at a height position corresponding to the substrate W.

Heating system, substrate, gas supply hole, gas supply system, substrate holding area

Description

Technical Field [0001] The present invention relates to a semiconductor device manufacturing apparatus and a semiconductor device manufacturing method,

The present invention relates to a semiconductor device manufacturing apparatus for forming an alumina film containing a-alumina (? -Al ₂ O ₃ ;? -Type aluminum oxide) on a substrate for manufacturing a semiconductor device, a semiconductor device manufacturing method, and a program And more particularly to a computer readable medium containing instructions. Here, the semiconductor device manufacturing technology refers to a technique of forming a semiconductor layer, an insulating layer, a conductive layer, and the like on a workpiece such as a semiconductor wafer or a flat panel display (FPD) such as a liquid crystal display To thereby form a structure including a semiconductor device, a wiring connected to the semiconductor device, an electrode, and the like on the object to be processed.

High integration and miniaturization of semiconductor devices are progressing and there is a tendency to diversify the device structure. However, along with this, efforts are being made to select and develop a more suitable film in terms of characteristics and manufacturing process.

The memory device 100 used as a flash memory of the MONOS (Metal-Oxide-Nitride-Oxide-Semiconductor) type, for example, has a structure in which the silicon between the source electrode 101 and the drain electrode 102 The charge trap layer 104, the blocking insulating film 105 and the control gate 106 on the silicon substrate 110 (the silicon substrate 110) (this control gate 106 is a polysilicon film) Is also referred to as a SONOS (Silicon-Oxide-Nitride-Oxide-Semiconductor) type. The charge trap layer 104 is formed of, for example, a silicon nitride film (Si ₃ N ₄ ). As the blocking insulating film 105, a film having a large band gap with respect to the silicon nitride film and a small leak current is used.

On the other hand, in a floating gate type flash memory conventionally used, a floating gate for storing a charge and a control gate for applying a control voltage are formed in a so-called ONO film in which both surfaces of a silicon nitride film are sandwiched by a silicon oxide film Layer insulating film.

However, in recent years, in the MONOS type memory device 100 described above, a technique using? -Al ₂ O ₃ as the blocking insulating film 105 has been studied. α-Al ₂ O ₃ has a corundum crystal structure and exists in many minerals. However, since the band gap is about 8.8 eV and the dielectric constant of the silicon nitride film is large, the physical film thickness can be increased. And can be suitably used as the blocking insulating film 105. When? -Al ₂ O ₃ is used, since the blocking insulating film has a one-layer structure, there is an advantage that the manufacturing process can be simplified compared with the floating gate type flash memory employing the ONO film for the gate insulating film.

? -Al ₂ O ₃ is obtained, for example, by forming TMA (trimethyl aluminum) as a raw material by reaction with ozone gas at a process temperature of about 300 ° C., and thereafter annealing at a high temperature of 1,100 ° C. or higher. Al ₂ O ₃ is amorphous at the stage of forming the film at about 300 ° C. and needs to be annealed at a high temperature of 1,100 ° C. or more for phase transition to α-Al ₂ O ₃ type. When TMA is used to form the film at a temperature higher than 500 ° C, the TMA supplied into the processing vessel is pyrolyzed in vapor phase before reaching the center of the semiconductor wafer, and is largely consumed by adsorption on the wall surface of the processing vessel or on the edge of the semiconductor wafer So that a uniform alumina film can not be formed on the entire surface of the semiconductor wafer.

On the other hand, if the semiconductor wafer is annealed at a high temperature of 1,100 DEG C, unexpected thermal history remains in the portion where the semiconductor wafer is stacked up to that temperature, for example, the activity of the impurity implanted by ion implantation is changed from the designed value. Therefore, the annealing temperature can be set only up to about 1,000 ° C. in an actual manufacturing process. However, if the alumina film is made of a spinel structure such as γ-Al ₂ O ₃ , θ-Al ₂ O ₃ or η-Al ₂ O ₃ Al ₂ O _3, which contains Al ₂ O _3, can hardly form α-Al ₂ O ₃ . As a result, the obtained bandgap of Al ₂ O ₃ is lowered to about 7.0 to 7.5 eV, and the target characteristics can not be obtained by using? -Al ₂ O ₃ . Due to such process problems, the application of α-Al ₂ O ₃ in the MONOS structure of the flash memory is inhibited.

Aluminum chloride (AlCl ₃ ) and titanium chloride (TiCl ₄ ) are alternately reacted with water vapor in a treatment vessel to produce an alumina film and an oxide film A technique of depositing an ATO film in which titanium films are alternately stacked is disclosed. However, the art is in particular techniques for forming the alumina film containing the α-Al ₂ O ₃ is not to solve the above problem, but it is not described.

Japanese Patent Application Laid-Open No. 10-96081 (paragraph 0004) discloses a technique of reacting aluminum chloride with moisture to form an alumina film on the surface of a cutting tool. However, in the related art, There is no description of a method for forming an alumina film containing ₂ O ₃ . Particularly, in application to the manufacture of semiconductor devices, it is required to form an alumina film having a uniform film thickness on the surface of a semiconductor wafer. However, Patent Document 2 does not describe a technique for solving such problems, Even if the alumina film formed contains α-Al ₂ O ₃ , it can not be applied to the production of semiconductor devices.

An object of the present invention is to provide a semiconductor device manufacturing apparatus, a semiconductor device manufacturing method, and a program instruction for implementing the method, which can form an alumina film containing? -Alumina and having a high in-plane uniformity without annealing at a high temperature And to provide a computer readable medium containing the same.

A first aspect of the present invention is a semiconductor device manufacturing apparatus for forming an alumina film containing a-alumina on a substrate for manufacturing a semiconductor device, comprising: a vertical reaction vessel; and a plurality of substrates, A gas supply hole for supplying a source gas containing aluminum chloride is provided at a height position corresponding to each substrate held in the substrate holding support region in the reaction vessel, And a gas supply hole for supplying an oxidizing gas containing water vapor is formed at a height position corresponding to each substrate held in the substrate holding support in the reaction vessel A second gas supply system, a heating system provided so as to surround the periphery of the reaction vessel, And a control unit for controlling an arbitrary operation of the apparatus, wherein the control unit controls the heating system to heat the processing atmosphere in the reaction vessel to a temperature within the range of 800 ° C or more and 1,000 ° C or less Simultaneously supplying the raw material gas and the oxidizing gas from the gas supply hole of the first gas supply system and the gas supply hole of the second gas supply system to the reaction vessel at the same time to cause an alumina film Is set in advance to output a control signal for film formation.

A second aspect of the present invention is a method of manufacturing a semiconductor device for forming an alumina film including a-alumina on a substrate for manufacturing a semiconductor device, the method comprising the steps of: holding a plurality of substrates in a rack shape by a substrate- A step of introducing these substrates into a reaction vessel, a step of heating the processing atmosphere in the reaction vessel to a temperature of 800 ° C or more and 1,000 ° C or less, And an oxidizing gas containing water vapor is supplied from the gas supply hole of the second gas supplying system. The raw material gas and the oxidizing gas are reacted to form an alumina film on the surface of each substrate Wherein the first gas supply system and the second gas supply system are each provided with a step Supply hole, are provided at the height position corresponding to the substrate which is held by the holder holding the substrate in the reaction vessel.

A third aspect of the present invention is a computer-readable medium including a program instruction for execution on a processor, the program instruction being executable by a processor to control a semiconductor device manufacturing apparatus A method of manufacturing a semiconductor device for forming an alumina film containing a-alumina on a substrate, the method comprising: holding a plurality of substrates in a rack shape by a substrate holding support, A step of heating the processing atmosphere in the reaction vessel to a temperature of 800 ° C or higher and 1,000 ° C or lower; and a step of supplying a raw material containing aluminum chloride from the gas supply hole of the first gas supply system, The gas is supplied from the gas supply hole of the second gas supply system, And a step of forming an alumina film on the surface of each substrate by reacting the source gas with the oxidizing gas, wherein the step of forming an alumina film on the surface of each substrate comprises: The supply hole is provided at a height position corresponding to each substrate held in the substrate holding region in the reaction vessel.

According to the present invention, there is provided a semiconductor device manufacturing apparatus, a semiconductor device manufacturing method, and a program instruction for implementing the method, which can form an alumina film containing? -Alumina and having a high in-plane uniformity without annealing at a high temperature And a computer readable medium.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, constituent elements having substantially the same functions and configurations are denoted by the same reference numerals, and redundant explanations are made only when necessary.

Before describing the configuration of the semiconductor device manufacturing apparatus according to the present embodiment, the present invention will be briefly described. As described in the background art, the film of alumina is deposited at a relatively low temperature of about 300 ℃ by the TMA as a raw material, subjected to annealing at more than 1,100 ℃ temperature in the film formation by phase change to crystallize the amorphous shaped Al ₂ O ₃ α -Al ₂ O ₃ . Therefore, the inventors and the temperature higher than the deposition temperature (300 ℃) of TMA, also an amorphous form and γ-Al ₂ O _3, etc., the annealing temperature is performed in the spinel structure in the Al ₂ O ₃ to obtain the α-Al ₂ O ₃ of ( Al ₂ O ₃ without annealing by depositing an alumina film within a temperature range lower than the temperature range of 800 ° C. to 1,000 ° C. in order to obtain α-Al ₂ O _{3. As} a result, aluminum chloride (AlCl ₃ ) It was found that an alumina film containing? -Al ₂ O ₃ can be formed by reacting with an oxidizing gas. In this semiconductor device manufacturing apparatus of the same finding to the present embodiment on the basis is, the AlCl ₃ as a raw material gas, and without the annealing step is configured to be capable of deposition of alumina film containing α-Al ₂ O _3.

When AlCl ₃ is reacted at a relatively high temperature of 800 ° C to 1,000 ° C, it is also necessary to exhibit activity in an oxidizing gas to be reacted with AlCl ₃ within this temperature range. In this respect, it is known that ozone gas conventionally used as an oxidizing gas of TMA tends to lose activity in such a temperature range. Therefore, the semiconductor device manufacturing apparatus according to the present embodiment is also characterized in that water vapor which does not lose its activity even in a relatively high temperature range of 800 deg. C to 1,000 deg. C is employed as the oxidizing gas.

Hereinafter, an embodiment in which the present invention is applied to a vertical type heat treatment apparatus as a batch type semiconductor device manufacturing apparatus will be described using a longitudinal sectional view of FIG. A semiconductor device manufacturing apparatus (hereinafter referred to as a film forming apparatus 1) according to the present embodiment is a film forming apparatus for forming wafers W (W) by a CVD (Chemical Vapor Deposition) process in which a raw material gas and an oxidizing gas are supplied simultaneously, As shown in Fig.

In Fig. 2, reference numeral 2 is a reaction vessel constituting a processing vessel formed, for example, in the shape of a vertical cylinder by quartz. A lower end of the reaction vessel 2 is opened as a furnace outlet and a flange 22 is formed integrally with the reaction vessel 2 on the periphery of the opening 21. A quartz lid body 23 which hermetically closes the opening 21 in contact with the lower surface of the flange 22 is provided below the reaction vessel 2 by a boat elevator As shown in Fig. A rotary shaft 24 is provided through the center of the lid body 23 and a wafer boat 25 as a substrate holder is mounted on the upper end of the lid 23.

The wafer boat 25 is provided with three or more support pillars 26, for example, so as to be able to hold a plurality of, for example, 125 wafers W in the form of a shelf, The support pillars 26 are formed with a plurality of grooves (slots) constituting a substrate holding portion. However, a plurality of dummy wafers are held within the holding area of the 125 wafers W, and the product wafers W are held in the area between the dummy wafers. A motor M constituting a driving unit for rotating the rotary shaft 24 is provided at a lower portion of the rotary shaft 24. The motor M rotates the entire wafer boat 25 through a rotary shaft 24 in a horizontal plane As shown in FIG. A heat insulating unit 27 is provided on the lid body 23 so as to surround the rotary shaft 24.

In the reaction vessel 2, there are provided injectors 31 and 34, that is, a first gas injector 31 for supplying a process gas, which is a gas supply system composed of two L-shaped pipes, A second gas injector 34 is inserted through the flange 22 under the reaction vessel 2. As shown in Fig. 2, the first gas injector 31 is vertically raised to the upper end of the wafer boat 25, and the pipe wall of the vertical riser portion is supported by the wafer boat 24 And a gas supply hole 311 is formed at a height position corresponding to each of the wafers W formed. Here, the " height position corresponding to each wafer W " is not limited to the case where the height position of each gas supply hole 311 strictly coincides with each of the wafers W held by the wafer boat 25 The height position of the gas supply hole 311 and the wafer W may be shifted by several millimeters in the vertical direction and the gas supply holes 311 may be formed for every wafer W purchase, Maybe.

The first gas injector 31 is connected to the raw material gas supply path 32 on the upstream side and the valves V1 and V2 and the mass flow controller MFC1 are connected to the upstream side of the raw material gas supply path 32 And a raw material source supply source 33 is connected. Anhydrous aluminum chloride (AlCl ₃ ) in the form of solid, for example, is stored in the raw material supply source 33. By heating a container made of AlCl ₃ by a heating system (not shown) made of, for example, AlCl ₃ is sublimated to obtain AlCl ₃ gas (source gas). On the upstream side of the inert gas supply passage 32B branching from the first injector 31 is introduced an inert gas such as nitrogen gas through a mass flow controller MFC5 provided with valves V8, And a nitrogen gas supply source 30B stored therein. Here, the gas supply passages 32 and 32B, the raw material source supply source 33, the gas supply source 30B and various valves V1, V2, V8 and V9 and the mass flow controllers MFC1 and MFC5 are connected to the raw gas supply portion 3a, .

The second gas injector 34 has substantially the same configuration as the first gas injector 31 described above and vertically rises up to the upper end of the wafer boat 25, A supply hole 341 is formed so that gas can be supplied to a height position corresponding to each of the wafers W held by the wafer 25. [ As in the case of the gas supply holes 311 of the first gas injector 31, the height positions of the gas supply holes 341 and the wafers W Or may be configured to form one gas supply hole 341 for each wafer W purchase.

As shown in Fig. 2, the second gas injector 34 is arranged so as to face the wafer boat 25 on the wafer boat 25 with respect to the opening direction of the gas supply holes 311 formed in the first gas injector 31 W in the radial direction of the reaction vessel 2 so that the respective gas supply holes 341 of the second gas injector 34 are opened.

The second gas injector 34 is branched into two at the upstream side and is connected to the oxidizing gas supply path 35 and the inert gas supply path 39, respectively. A steam generator 36 is connected to the oxidizing gas supply path 35 via a valve V5. The water vapor generator 36 is provided with a hydrogen gas supply source 37 and an oxygen gas supply source 38 via mass flow controllers MFC3 and MFC4 and valves V6 and V7, The oxygen gas can be supplied to the steam generator 36.

Here, the steam generator 36 is provided with a heating system for heating the gas passing through the inside thereof, and a catalyst such as platinum is installed in the gas flow path, and oxygen gas and hydrogen gas are supplied at a temperature of, for example, Or less and is brought into contact with the catalyst to generate steam. The water vapor generator 36 can change the concentration of the water vapor supplied into the reduced pressure reaction vessel 2 from 1 vol% to 90 vol% based on the concentration of water vapor for water vapor and oxygen gas have. It goes without saying that, in the supply of water vapor, a vaporizer for vaporizing water to obtain water vapor may be used instead of the supply of water vapor using such a catalyst.

The inert gas supply path 39 branched from the second injector 34 is connected to the upstream side of the inert gas supply path 39 via a mass flow controller MFC2 provided with valves V3 and V4 on the upstream and downstream sides, A nitrogen gas supply source 30 stored in a cylinder or the like is provided. The various gas supply passages 35 and 39, the valves V3 to V7, the gas supply sources 37, 38 and 30 and the water vapor generator 36 constitute the gas supply unit 3b.

Further, in the reaction vessel 2, an exhaust port 4 for exhausting the inside of the reaction vessel 2 is connected to this opening for exhausting from an opening formed at the center of its top portion. The exhaust port 4 is connected to an exhaust pipe 43 having a vacuum pump 41 and a pressure control system 42 capable of decompressing and discharging the inside of the reaction vessel 2 to a desired degree of vacuum. The vacuum pump 41 and the pressure adjusting system 42 constitute an exhaust system. A heating furnace 45 having a heater 44 as a heating system for heating the inside of the reaction vessel 2 is provided around the reaction vessel 2. As the heater 44, it is preferable to use a carbon wire or the like which is free from contemination and has excellent lift-up characteristics.

The film forming apparatus 1 further includes a control section 5 for controlling the operations of the heater 44, the pressure adjusting system 42 and the gas supply sections 3a and 3b. The control unit 5 is composed of a CPU and a program, not shown, for example. The program includes an operation required to perform the film forming process on the wafer W by the film forming apparatus 1, for example, (Command) group for the temperature control of the reaction vessel 2, the control of the temperature of the reaction vessel 2, the control of the pressure in the reaction vessel 2, and the control of the supply amount of the processing gas and the oxidizing gas to the reaction vessel 2. This program is stored in a storage medium such as a hard disk, a compact disk, a magnet optical disk, a memory card, or the like, and is installed in the computer therefrom.

Next, an example of a film forming method performed using the film forming apparatus 1 will be described with reference to a sequence diagram shown in Fig. 3 (a) shows the processing temperature in the reaction vessel 2, FIG. 3 (b) shows the supply timing of the source gas (AlCl ₃ ) to the reaction vessel 2, And FIG. 3 (d) shows the supply timing of the purge gas (nitrogen gas).

First, a source electrode 101 and a drain electrode 102 are formed on a wafer W to be processed, for example, a P-type silicon substrate 110 as shown in FIG. 4A. On the tunnel oxide film 103, A wafer W having a silicon oxide film 103a as a charge trapping layer 104 and a silicon nitride film 104a as a charge trapping layer 104 is held by a predetermined number of wafer boats 25, The wafer boat 25 is loaded (loaded) by raising a boat elevator (not shown) in the reaction vessel 2 maintained at, for example, a temperature of about 150 占 폚, as shown in Fig.

Subsequently, when the lower end opening 21 of the reaction vessel 2 is closed by the lid body 23, as shown in Fig. 3A, the temperature in the reaction vessel 2 is maintained at 200 DEG C / min For example, 950 占 폚 at a temperature raising rate of 800 占 폚 or more and 1,000 占 폚 or less and at the same time the inside of the reaction vessel 2 is exhausted through the exhaust port 4 by the vacuum pump 41 as for example in the range of 13.3 ㎩ (0.1 Torr) to ^{1.3 × 10 3 ㎩ (10 Torr} ) is evacuated to a degree of 33.3 ㎩ (0.25 Torr) pressure.

After the temperature rise and the exhaust in the reaction vessel 2 are completed, the process moves to the step of forming the film on the wafer W while continuing the operation of the vacuum pump 41. 3 (b), AlCl ₃ gas is continuously supplied into the reaction vessel 2 at a flow rate of, for example, 30 sccm to 300 sccm, for example, 30 sccm. At this time, the AlCl ₃ gas is heated while rising in the first gas injector 31, and at the height position corresponding to each of the wafers W held in the form of a shelf in the wafer boat 25, the gas supply holes 311 To the wafer W.

In parallel with the supply of the AlCl ₃ gas from the first gas injector, as shown in FIG. 3 (c), for example, steam of 90% by volume in concentration is introduced into the second gas injector from 20 to 500 sccm For example, at a flow rate of 50 sccm. At this time, the water vapor is also raised while rising in the second gas injector 34, and the gas supply holes 341 are formed at the height positions corresponding to the wafers W held in the form of a shelf in the wafer boat 25, And is discharged toward the wafer W.

When the AlCl ₃ gas and the water vapor are continuously supplied into the reaction vessel 2 at the same time, these gases react with each other based on the reaction formula shown in the following formula (1) to form Al ₂ O ₃ .

[Formula 1]

Here, the atmosphere in the reaction vessel _{2 in} which Al ₂ O ₃ is formed is a temperature atmosphere of 950 ° C. in the range of 800 ° C. to 1,000 ° C. as described above. However, in this temperature range, the vapor pressure of the AlCl ₃ gas is high When supplying the AlCl ₃ gas into the reaction vessel 2 in a single dock, resulting in AlCl ₃ gas is discharged from the reaction vessel (2) little or no adsorption onto the wafer (W).

Therefore, in the film forming apparatus 1 according to the present embodiment, as described above, it corresponds to each wafer W vertically raised to the upper end of the wafer boat 25 and held in a rack shape on the wafer boat 25 AlCl ₃ gas is supplied from a gas supply hole 311 formed at a height position, and at the same time as the supply of the AlCl ₃ gas, steam as an oxidizing gas is supplied. By thus supplying the AlCl ₃ gas and the water vapor at the same time, the reaction shown in the formula (1) is advanced in the vicinity of the surface of the wafer W, and the generated Al ₂ O ₃ is deposited on the surface of the wafer W, It is possible to form an alumina film.

Also, since the reaction of AlCl ₃ gas and water vapor shown in Equation 1 has a very high reaction rate, these gases rapidly form Al ₂ O ₃ upon contact. This allows the gas supplied from the gas supply holes 311 and 341 to be supplied to the injectors 31 and 34 by supplying the AlCl ₃ gas and the water vapor from the two gas injectors 31 and 34 arranged adjacent to each other, The reaction occurs immediately on the wall surface of the reaction vessel 2 in the vicinity and in the vicinity of the periphery of the wafer W. As a result, the alumina film can not be formed on the entire surface of the wafer W.

Therefore, in the film forming apparatus 2 according to the present embodiment, the gas supply holes 311 of the first injector and the gas supply holes 341 of the second gas injector 34 are formed on the wafer boat 25 And are arranged to face each other in the radial direction of the wafer W. This allows each of the gases supplied from the gas supply holes 311 and 341 to be in contact with each other while diffusing the wafer W in the radial direction, thereby making it possible to form a uniform alumina film in the radial direction of the wafer W. During the film forming period, since the wafer boat 25 is rotated by the motor M, it is possible to form a uniform alumina film in the circumferential direction of the wafer W.

In addition, in the film forming apparatus 1 according to the present embodiment, in addition to the above-described apparatus configuration in which an alumina film having a uniform film thickness is formed by opposing the gas supply holes 311 and 341 in the radial direction of the wafer W Thus, adjustment is made to form an alumina film having a uniform film thickness under the process conditions. That is, in the reaction shown in equation 1, AlCl ₃ gas and discarded is any one of water vapor to one side, or the supply amount of both is too large, the reaction rapidly proceeding to the right, prior to the respective gas to spread sufficiently uniformly to the wafer (W) the surface of Al ₂ O ₃ is formed, and an alumina film having a nonuniform film thickness (which is inferior in in-plane uniformity) is also formed. On the other hand, when the supply amount ratio of these gases is balanced and the alumina film is uniformly formed on the surface of the wafer W, if the supply amount of these gases is too small, the film forming time becomes long.

Therefore, as shown in the experimental results in the following embodiments, the film forming apparatus 1 according to the present embodiment is configured such that (A) the supply amount of the AlCl ₃ gas is, for example, 30 sccm to 300 sccm, for example, 30 sccm (B) setting the supply ratio of water vapor to the supply amount of the AlCl ₃ gas to, for example, 1.7 (50 sccm) within the range of, for example, 1.3 to 1.7, thereby forming a uniform alumina film .

Further, in the film forming apparatus 1, film formation was performed at a relatively high temperature of 950 占 폚 in the range of 800 占 폚 to 1,000 占 폚. As a result, unstable oxidizing gas such as ozone gas tended to lose its activity as an oxidizing gas in such a temperature range . On the contrary, in the film forming apparatus 1 according to the present embodiment, water vapor is employed as the oxidizing gas, and since the water vapor has a stable oxidizing power even in the above-mentioned temperature range, The alumina film 105a can be formed.

By continuously supplying AlCl ₃ gas and water vapor for 30 minutes under such apparatus conditions and process conditions, an alumina film 105a is formed on the surface of the wafer W as shown in FIG. 4B. Here, since the film formation is performed at a temperature of 950 占 폚 in the range of 800 占 폚 to 1,000 占 폚, which is higher than the film forming temperature 300 占 폚 of the conventional film forming method using TMA, the alumina film 105a is crystallized during film formation, The inventors have found that a relatively large amount of? -Al ₂ O ₃ is contained in the crystallized alumina film 105a. As a result, for example, all is increased the art alumina film (105a) the average bandgap of the total of the silicon nitride film (104a) relative to the alumina film, which is composed of γ-Al ₂ O _3, to reduce the leakage current Lt; / RTI >

The temperature in the range of 800 占 폚 to 1,000 占 폚 is the temperature at which the portions of the P-type silicon substrate 110 and the silicon oxide film 103a on which the electrodes 101 and 102 are formed, (The nitride film 104a) is relatively small.

Returning to the description of the operation of the film forming apparatus 1, if the alumina film 105a is formed on the silicon nitride film 104a by the above-described steps, The supply of AlCl ₃ gas and water vapor into the reaction vessel 2 is stopped. Then, the cycle purge operation of the reaction vessel 2, which repeats the supply and stop of the purge gas (nitrogen gas) while exhausting the inside of the reaction vessel 2, is performed. 3 (d), while the purge gas is being supplied from the inert gas supply path 39, the pressure in the reaction vessel 2 is returned to the atmospheric pressure and the temperature in the reaction vessel 2 is set to, for example, The wafer boat 25 is removed (unloaded) from the reaction vessel 2 by stopping the supply of the purge gas. The series of processes described above are performed by controlling the heater 44, the pressure adjusting system 42, the gas supply units 3a and 3b, and the like based on the process recipe stored in the control unit 5. [

A polycrystalline silicon film 106a serving as a control gate 106 is formed on the alumina film 105a as shown in Fig. 4C on the wafer W taken out of the reaction vessel 2. Subsequently, as shown in Fig. Thereafter, the gate structures of the tunnel oxide film 103 to the control gate 106 are obtained from these laminated structures by photolithography or the like and the signal lines are connected to the electrodes 101 and 102 and the control gate 106, The memory element 100 of the flash memory having the structure shown in Fig.

The film forming apparatus 1 according to the embodiment described above has the following effects. Al ₂ O ₃ -containing alumina film 105a is formed by reacting AlCl ₃ gas as a raw material gas and water vapor as an oxidizing gas at a temperature of 800 ° C to 1,000 ° C. In the above-mentioned temperature range, the reaction speed of aluminum chloride and water vapor is very high. However, in the reaction vessel 2 of the film forming apparatus 1, the wafers W from the side of the upper and lower groups of wafers W, Since the raw gas and the oxidizing gas are supplied by the individual gas injectors 31 and 34 to the central region of the wafer W, ) Can be obtained.

The alumina film 105a formed by the film forming apparatus 1 according to the present embodiment is also not limited to the case of being used as the blocking insulating film 105 of the MONOS type flash memory shown in the embodiment. For example, the alumina film 105 formed by the film forming apparatus 1 according to the present embodiment can also be applied to an insulating film of a DRAM capacitor.

[Example]

(Experiment 1)

2 was used to form an alumina film 105a on the wafer W by reacting AlCl ₃ gas and water vapor, and the crystal structure thereof was examined. As a comparative example, the alumina film 105a formed by the conventional method using TMA was subjected to annealing, and its crystal structure was examined. The film formation of the alumina film 105a is performed by the CVD method in which the raw material gas and the oxidizing gas are continuously supplied for the following (first embodiment), and the raw material gas and the oxidizing gas are alternately By the MLD method.

A. Experimental conditions

(Embodiment 1)

Raw material gas: AlCl ₃ gas

Oxidizing gas: water vapor

Process temperature: 950 ℃

Process pressure: 33.3 Pa (0.25 Torr)

Feed rate of raw material gas: 30 sccm

Supply amount of oxidizing gas: 50 sccm

Duration: 30 minutes

(Comparative Example 1)

Film formation conditions

Raw material gas: TMA gas

Oxidizing gas: ozone gas

Process temperature: 300 ° C

Process pressure:

TMA gas 40.0 Pa (0.3 Torr)

Ozone gas 133.3 Pa (1.0 Torr)

Feed rate of feed gas: 300 sccm

Supply amount of oxidizing gas: 200 g / Nm 3 (concentration in oxygen gas 10 slm)

Tentative time:

TMA gas 15 sec / cycle

Ozone gas 20 sec / cycle

Total 200 cycles

Annealing condition

Process atmosphere: nitrogen atmosphere

Process temperature: 1,000 ℃

Process pressure: 1.01 × 10 ⁵ ㎩ (atmospheric pressure)

Burn time: 60 minutes

B. Experimental Results

5 is a graph summarizing the composition ratio of the crystal structure of Al ₂ O ₃ contained in the alumina film 105a obtained in the first embodiment and the first comparative example. The column on the left side of the graph shows the composition ratio of the alumina film 105a obtained in the first embodiment and the column on the right side shows the composition ratio in the first comparative example. The composition ratio of each alumina film was determined by analyzing image data obtained from a TEM (Transmission Electron Microscope).

(Example 1), the alumina film 105a obtained by reacting AlCl ₃ gas and water vapor at a process temperature of 950 ° C contains four kinds of crystal structures in the phase of?,?,?, And? Phases. . Of these,? -Al ₂ O ₃ (? Phase), which is the target material of the present embodiment, was the third largest in the? -Phase and? -Phase for the third time, and contained 18% of the entire alumina film 105a.

On the other hand, in the alumina film 105a obtained by combining the film formation using TMA and the subsequent annealing (first comparative example), six kinds of crystal structures including χ-phase and θ-phase were included, Al ₂ O ₃ (alpha phase) was the smallest among these six kinds of crystal structures and contained only 3% of the total.

From these results, it can be seen that comparing the alumina films 105a obtained in the respective experiments (Example 1) and (Comparative Example 1), the alumina film 105a obtained from the AlCl ₃ gas and the water vapor (Example 1) 105a) include a (may contain about 6 times the α-Al ₂ O ₃ of the first comparative example). As a result, the average band gap of the alumina film 105a formed in the first example is higher than that in the first comparative example and the use of the alumina film 105a of the first example It is possible to reduce the leakage current when the MONOS type flash memory is constructed.

(Experiment 2)

When the AlCl ₃ gas and the water vapor are reacted to form the alumina film 105a by using the film forming apparatus 1 shown in FIG. 2, the supply amount of the AlCl ₃ gas is fixed to change the supply amount of the water vapor, The uniformity of the film thickness of the alumina film and the film thickness between the central portion and the peripheral portion of the wafer W was examined.

A. Experimental conditions

Raw material gas: AlCl ₃ gas

Oxidizing gas: water vapor

Process temperature: 950 ℃

Process pressure: 33.3 Pa (0.25 Torr)

Feed rate of raw material gas: 30 sccm

Duration: 5 minutes

(Second Embodiment)

Supply amount of oxidizing gas (in terms of 100 vol%): 40 sccm

Feed ratio R (steam supply / AlCl ₃ gas supply): 1.33

(Third Embodiment)

Supply amount of oxidizing gas (in terms of 100 volume%): 50 sccm

Feed ratio R: 1.67

(Comparative Example 2)

Supply amount of oxidizing gas (in terms of 100 vol%): 25 sccm

Feed ratio R: 0.83

(Comparative Example 3)

Supply amount of oxidizing gas (in terms of 100 vol%): 75 sccm

Feed ratio R: 2.50

B. Experimental Results

Fig. 6 shows the result of plotting the film thickness of the alumina film 105a obtained in each of the examples and the comparative examples in Experiment 2 on the wafer W in a predetermined region. In the figure, the abscissa indicates the amount of water vapor supplied during film formation, and the ordinate indicates the film thickness of the alumina film 105a. The construction of the black circle circle " " is an average value of the film thicknesses at the measurement points of the peripheral edges of the wafers W of the alumina film 105a obtained in these examples and the comparative example, and the triangle " Is an average film thickness at 25 measurement points in the central portion of the wafer W. [ The construction of the diamond-shaped "? &Quot; painted in black is an average film thickness of 49 measurement points of the entire wafer W. In addition, the surrounded part of the broken line indicates the measurement result obtained in the same embodiment and the comparative example.

6, the film thickness of the periphery of the wafer W tends to become thicker than the film thickness of the central portion in both the (second and third embodiments) and (the second and third comparative examples). 2, since Al ₂ O ₃ gas or water vapor is supplied from the respective gas injectors 31 and 34 to the periphery of the wafer W, the film formation first proceeds in the vicinity of the gas supply part, It is considered that the film thickness becomes thicker than the central portion of the distant wafer W. [

However, in the second embodiment (supply ratio R = 1.33) and in the third embodiment (R = 1.67), the difference in film thickness between the periphery of the wafer W and the central portion is about 5 nm, (Third comparative example) (R = 2.50), the film thickness difference is four times as wide as about 20 nm. This is because the excessive water vapor is supplied to the vicinity of the gas injector 34 to which water vapor is supplied so that the reaction of the equation (1) rapidly progresses at the periphery of the wafer W close to the injector 34, And the AlCl ₃ gas to be spread evenly in the periphery is also consumed in the periphery. This is because, when the film thickness of the entire wafer W is compared between the third embodiment and the third comparative example, a large difference is not seen, and there is no large difference in the total amount of alumina deposited on the wafer W It can also be explained from the point of view.

On the other hand, the difference in the film thickness between the peripheral portion and the central portion of the wafer W as in Comparative Example 3 is not shown in the case where the supply amount of water vapor is small (Comparative Example 2) (R = 0.83) ) Is less than about half of the thickness of the second embodiment, so that the deposition rate is slow. This is thought to be because the amount of water vapor supplied to the supply amount of AlCl ₃ gas is excessively small, so that the reaction of Equation 1 is difficult to proceed to the right. Points from the film formation speed is not too slow or more, and in order just to make good the in-plane uniformity of the thickness, when a 30 sccm in the range of the supply amount of the AlCl ₃ gas, for example 30 sccm to about 50 sccm, AlCl ₃ It may be said that it is appropriate to adjust the supply ratio of the water vapor to the supply amount of the gas within the range of, for example, 1.3 to 1.7.

According to the embodiment of the present invention, an alumina film containing? -Al ₂ O ₃ is formed by reacting a raw material gas containing aluminum chloride and an oxidizing gas containing water vapor at a temperature of 800 ° C to 1,000 ° C. In the above-mentioned temperature range, the reaction rates of aluminum chloride and water vapor are very high. In the reaction vessel of the vertical type, raw material gas and oxidizing gas are supplied to the respective substrates from the sides of the substrate groups arranged above and below by individual supply systems Therefore, an alumina film having a high in-plane uniformity can be obtained because the gases on both sides reach the central region of the substrate uniformly and react with each other.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing the structure of a MONOS type memory element in which an alumina film according to an embodiment of the present invention is used. Fig.

2 is a longitudinal sectional view showing a film forming apparatus for carrying out a film forming method according to an embodiment of the present invention.

3 is a sequence diagram showing the operation of the film forming apparatus.

FIGS. 4A, 4B and 4C are longitudinal sectional views showing a manufacturing process of the MONOS type memory device. FIG.

5 is a characteristic view showing a composition ratio of a crystal structure of an alumina film formed by using another source gas.

6 is a characteristic diagram showing a change in the film thickness of the alumina film formed by changing the process conditions of the film formation apparatus.

Description of the Related Art

1: Deposition device

2: reaction vessel

21: opening

22: Flange

23:

24:

25: Wafer Boat

26: Support column

27: Insulation unit

36: Water vapor generator

W: Wafer

V1 to V9: valves

MFC1 to MFC5: mass flow controller

Claims (20)

1. A semiconductor device manufacturing apparatus for forming an alumina film containing? -Alumina on a substrate for manufacturing a semiconductor device, A vertical reaction vessel, A substrate holder for holding a plurality of substrates in a rack shape and carrying them into the vertical reaction vessel, A first gas supply system in which a gas supply hole for supplying a source gas containing aluminum chloride is formed at a height position corresponding to each substrate held in the substrate holding support in the reaction vessel; A second gas supply system in which a gas supply hole for supplying an oxidizing gas including water vapor is formed in a height position corresponding to each substrate held in the substrate holding support in the reaction vessel; A heating system provided so as to surround the periphery of the reaction vessel, An exhaust system for exhausting the inside of the reaction vessel, Wherein the control unit controls the heating system to heat the processing atmosphere in the reaction vessel to a temperature within the range of 800 ° C or more and 1,000 ° C or less, A control signal for forming an alumina film on the surface of each substrate is formed by simultaneously supplying the source gas and the oxidizing gas into the reaction vessel through the gas supply hole of the supply system and the gas supply hole of the second gas supply system Lt; / RTI > The supply amount of aluminum chloride contained in the source gas is in the range of 30 cc / min to 300 cc / min, Wherein the alumina film is used as an insulating film made of a high-dielectric material. delete delete 2. The semiconductor device manufacturing apparatus according to claim 1, wherein a supply amount ratio of steam contained in the oxidizing gas to a supply amount of aluminum chloride contained in the source gas is in a range of 1.3 to 1.7. delete 1. A semiconductor device manufacturing apparatus for forming an alumina film containing? -Alumina on a substrate for manufacturing a semiconductor device, A vertical reaction vessel, A substrate holder for holding a plurality of substrates in a rack shape and carrying them into the vertical reaction vessel, A first gas supply system in which a gas supply hole for supplying a source gas containing aluminum chloride is formed at a height position corresponding to each substrate held in the substrate holding support in the reaction vessel; A second gas supply system in which a gas supply hole for supplying an oxidizing gas including water vapor is formed in a height position corresponding to each substrate held in the substrate holding support in the reaction vessel; A heating system provided so as to surround the periphery of the reaction vessel, An exhaust system for exhausting the inside of the reaction vessel, Wherein the control unit controls the heating system to heat the processing atmosphere in the reaction vessel to a temperature within the range of 800 ° C or more and 1,000 ° C or less, A control signal for forming an alumina film on the surface of each substrate is formed by simultaneously supplying the source gas and the oxidizing gas into the reaction vessel through the gas supply hole of the supply system and the gas supply hole of the second gas supply system Lt; / RTI > The alumina film is used as an insulating film made of a high dielectric material, Wherein the alumina film is used as the blocking insulating film in a memory element in which a tunnel oxide film, a charge trap layer, a blocking insulating film, and a control gate are stacked in this order from below. 1. A semiconductor device manufacturing apparatus for forming an alumina film containing? -Alumina on a substrate for manufacturing a semiconductor device, A vertical reaction vessel, A substrate holder for holding a plurality of substrates in a rack shape and carrying them into the vertical reaction vessel, A first gas supply system in which a gas supply hole for supplying a source gas containing aluminum chloride is formed at a height position corresponding to each substrate held in the substrate holding support in the reaction vessel; A second gas supply system in which a gas supply hole for supplying an oxidizing gas including water vapor is formed in a height position corresponding to each substrate held in the substrate holding support in the reaction vessel; A heating system provided so as to surround the periphery of the reaction vessel, An exhaust system for exhausting the inside of the reaction vessel, Wherein the control unit controls the heating system to heat the processing atmosphere in the reaction vessel to a temperature within the range of 800 ° C or more and 1,000 ° C or less, A control signal for forming an alumina film on the surface of each substrate is formed by simultaneously supplying the source gas and the oxidizing gas into the reaction vessel through the gas supply hole of the supply system and the gas supply hole of the second gas supply system Lt; / RTI > Wherein the first gas supply system and the second gas supply system are each constituted by a pipe vertically raised from the lower portion of the reaction vessel to the upper end of the substrate holding portion and the gas supply hole is formed in the pipe wall portion of the pipe, And is open toward the substrate held on the substrate holding support, The alumina film is used as an insulating film made of a high dielectric material, Wherein the gas supply hole of the first gas supply system and the gas supply hole of the second gas supply system are disposed so as to face each other with the substrate holding support therebetween. 8. The semiconductor device manufacturing apparatus according to claim 7, wherein the exhaust system is configured to exhaust from an opening formed in the center of the top of the reaction vessel. The substrate holding apparatus according to claim 8, further comprising a rotating mechanism for rotating the substrate holding support in a horizontal plane, wherein the controller controls the rotation of the substrate holding support Is set. 2. The semiconductor device manufacturing apparatus according to claim 1, wherein the control section is set so as to output a control signal for setting the inside of the reaction vessel to 13.3 to 1.3 x 10 ³ Pa when the alumina film is formed. A method of manufacturing a semiconductor device for depositing an alumina film containing? -Alumina on a substrate for manufacturing a semiconductor device, A step of holding a plurality of substrates in a rack shape by a substrate holding support and carrying these substrates into a vertical reaction vessel, Heating the processing atmosphere in the reaction vessel to a temperature of 800 ° C or more and 1,000 ° C or less, The raw material gas containing aluminum chloride is supplied from the gas supply hole of the first gas supply system and the oxidizing gas containing water vapor is supplied from the gas supply hole of the second gas supply system while exhausting the inside of the reaction vessel, And a step of forming an alumina film on the surface of each substrate by reacting the raw material gas with the oxidizing gas, The gas supply holes of each of the first gas supply system and the second gas supply system are provided at a height position corresponding to each substrate held in the substrate holding support in the reaction vessel, Wherein the alumina film is used as an insulating film made of a high-dielectric material. 12. The method for manufacturing a semiconductor device according to claim 11, wherein the supply amount of the aluminum chloride contained in the source gas is in the range of 30 cc / min to 300 cc / min. 13. The method of manufacturing a semiconductor device according to claim 12, wherein the supply amount ratio of water vapor contained in the oxidizing gas to the supply amount of aluminum chloride contained in the source gas is in the range of 1.3 to 1.7. delete 12. The method of claim 11, wherein the alumina film is used as the blocking insulating film in a memory element in which a tunnel oxide film, a charge trap layer, a blocking insulating film, and a control gate are stacked in this order from below. 12. The method of manufacturing a semiconductor device according to claim 11, wherein the gas supply holes of the first gas supply system and the gas supply holes of the second gas supply system are disposed so as to face each other with the substrate holder. 17. The method of manufacturing a semiconductor device according to claim 16, wherein, when the alumina film is formed, exhausting is performed from an opening formed at the center of the top of the reaction vessel. The method of manufacturing a semiconductor device according to claim 17, wherein when the alumina film is formed, the substrate holder is rotated in a horizontal plane. The method of manufacturing a semiconductor device according to claim 11, wherein, when the alumina film is formed, the inside of the reaction vessel is set to 13.3 to 1.3 x 10 ³ Pa. A computer-readable medium comprising program instructions for executing on a processor, Said program instruction executing, when executed by a processor, a semiconductor device manufacturing method for controlling a semiconductor device manufacturing apparatus to form an alumina film containing a-alumina on a substrate for manufacturing a semiconductor device, A step of holding a plurality of substrates in a rack shape by a substrate holding support and carrying these substrates into a vertical reaction vessel, Heating the processing atmosphere in the reaction vessel to a temperature of 800 ° C or more and 1,000 ° C or less, The raw material gas containing aluminum chloride is supplied from the gas supply hole of the first gas supply system and the oxidizing gas containing water vapor is supplied from the gas supply hole of the second gas supply system while exhausting the inside of the reaction vessel, And a step of forming an alumina film on the surface of each substrate by reacting the raw material gas with the oxidizing gas, The gas supply holes of each of the first gas supply system and the second gas supply system are provided at a height position corresponding to each substrate held in the substrate holding support in the reaction vessel, Wherein the alumina film is used as an insulating film made of a high-dielectric material.

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