JP6499493B2 - Vapor growth method - Google Patents

Description

  The present invention relates to a vapor phase growth method for forming a film by supplying a gas.

  As a method of forming a high quality and thick semiconductor film, there is an epitaxial growth technique in which a single crystal film is grown by vapor phase growth on a substrate such as a wafer. In a vapor phase growth apparatus using an epitaxial growth technique, a wafer is placed on a support in a reaction chamber that is maintained at normal pressure or reduced pressure. Then, while heating the wafer, a process gas such as a source gas as a film forming raw material is supplied to the wafer surface from, for example, a shower plate above the reaction chamber. A thermal reaction of the source gas occurs on the wafer surface, and an epitaxial single crystal film is formed on the wafer surface.

In recent years, gallium nitride (GaN) -based semiconductor devices have attracted attention as materials for light-emitting devices and power devices. As an epitaxial growth technique for forming a GaN-based semiconductor, there is a metal organic chemical vapor deposition method (MOCVD method). In the metal organic vapor phase epitaxy, an organic metal such as trimethylgallium (TMG), trimethylindium (TMI), trimethylaluminum (TMA), ammonia (NH ₃ ), or the like is used as a source gas. Further, hydrogen gas (H ₂ ) or the like may be used as a separation gas in order to suppress a reaction between source gases.

  When forming a GaN-based semiconductor film on a silicon (Si) substrate, it is known that it is difficult to grow a high-quality single crystal film. In order to solve this problem, Patent Document 1 describes a method of forming an aluminum nitride (AlN) buffer layer on a Si substrate, and a method of desorbing hydrogen atoms on the surface of the Si substrate before forming a GaN film. Has been. Patent Document 2 describes a method of flowing chlorine gas in order to remove deposits from chamber components in the process of forming a GaN-based semiconductor film using MOCVD.

JP 2006-261476 A Special table 2012-525708 gazette

  An object of the present invention is to provide a vapor phase growth method for forming a high-quality film on Si in the same reaction chamber in which a gas containing Ga is supplied.

In the vapor phase growth method of one embodiment of the present invention, a first substrate is carried into a reaction chamber, a first gas containing gallium (Ga) is supplied to the reaction chamber, and a first gas is supplied to the first substrate. 1 film is formed, the first substrate is unloaded from the reaction chamber, the second substrate is loaded into the reaction chamber, a second gas containing chlorine atoms is supplied to the reaction chamber, and A hydrogen gas or a third gas of an inert gas is supplied to the reaction chamber, an aluminum nitride film or a silicon nitride film is formed on the second substrate, and the second substrate is removed from the reaction chamber. The temperature of the second substrate when carrying out and supplying the third gas is higher than the temperature of the second substrate when supplying the second gas, and the second gas is supplied. The temperature of the second substrate at the time is 950 ° C. or higher and 1050 ° C. or lower .

In the vapor phase growth method of the above aspect, the third temperature of the second substrate at the time of supplying the gas, it is desirable and this is 1050 ° C. or higher 1200 ° C. or less.

  In the vapor phase growth method of the above aspect, after the second substrate is unloaded from the reaction chamber, a third substrate having a surface of silicon (Si) is loaded into the reaction chamber and nitrided on the third substrate. It is desirable to form a third film of an aluminum film or a silicon nitride film.

  In the vapor phase growth method of the above aspect, it is desirable that the thickness of the third film is larger than the thickness of the second film.

  In the vapor phase growth method of the above aspect, it is desirable to supply a fourth gas containing ammonia to the reaction chamber after supplying the third gas and before forming the second film.

  According to the present invention, it is possible to provide a vapor phase growth method for forming a high-quality film on Si in the same reaction chamber in which a gas containing Ga is supplied.

It is a schematic cross section of the vapor phase growth apparatus used with the vapor phase growth method of a 1st embodiment. It is a process flow figure of the vapor phase growth method of a 1st embodiment. It is a process flow figure of the vapor phase growth method of a 2nd embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the present specification, the direction of gravity in a state where the vapor phase growth apparatus is installed so as to be capable of film formation is defined as “down”, and the opposite direction is defined as “up”. Therefore, “lower” means a position in the direction of gravity with respect to the reference, and “downward” means the direction of gravity with respect to the reference. “Upper” means a position opposite to the direction of gravity relative to the reference, and “upward” means opposite to the direction of gravity relative to the reference. The “vertical direction” is the direction of gravity.

  In this specification, “process gas” is a general term for gases used for film formation on a substrate, and includes, for example, a concept including a source gas, a carrier gas, a separation gas, a compensation gas, and the like. .

  In this specification, “nitrogen gas” is included in “inert gas”.

(First embodiment)
In the vapor phase growth method of the present embodiment, a first substrate is carried into a reaction chamber, a first gas containing gallium (Ga) is supplied to the reaction chamber, and a first film is formed on the first substrate. Forming, unloading the first substrate from the reaction chamber, loading the second substrate into the reaction chamber, supplying a second gas containing chlorine atoms into the reaction chamber, and supplying hydrogen gas or inert gas into the reaction chamber The second gas is supplied to form a second film of an aluminum nitride film or a silicon nitride film on the second substrate, and the second substrate is unloaded from the reaction chamber.

  FIG. 1 is a schematic cross-sectional view of a vapor phase growth apparatus used in the vapor phase growth method of the present embodiment. The vapor phase growth apparatus of the present embodiment is a vertical and single wafer type epitaxial growth apparatus that uses MOCVD (metal organic chemical vapor deposition).

  The vapor phase growth apparatus includes, for example, a reaction chamber 10 made of stainless steel and having a cylindrical hollow body. A shower plate 11 is provided above the reaction chamber 10 and supplies process gas into the reaction chamber 10. A gas supply unit 13 for supplying process gas, cleaning gas, and the like into the reaction chamber 10 is provided on the upper portion of the shower plate 11.

  Further, a support portion 12 is provided in the reaction chamber 10 below the shower plate 11 and on which a semiconductor wafer (substrate) W can be placed. The support portion 12 may be, for example, an annular holder having an opening at the center as shown in FIG. 1 or a susceptor having a structure in contact with almost the entire back surface of the semiconductor wafer W.

  Moreover, the support part 12 is arrange | positioned on the upper surface, and the rotary body unit 14 rotated is provided. In addition, a heater is provided below the support unit 12 as the heating unit 16 that heats the wafer W placed on the support unit 12.

  The rotating shaft 18 of the rotating body unit 14 is connected to a rotation driving mechanism 20 located below. The rotation drive mechanism 20 can rotate the semiconductor wafer W around the center of rotation, for example, at 300 rpm or more and 1000 rpm or less.

  The diameter of the cylindrical rotating body unit 14 is desirably substantially equal to the outer diameter of the support portion 12. The rotary shaft 18 sandwiches a vacuum seal member between the bottom of the reaction chamber 10.

  The heating unit 16 is fixedly provided in the rotating body unit 14. Electric power is supplied to the heating unit 16 via an electrode 22 that penetrates the inside of the rotating shaft 18. Further, in order to detach the semiconductor wafer W from the annular holder 18, push-up pins (not shown) penetrating the heating unit 16 are provided.

  The vapor phase growth apparatus further includes a gas discharge unit 26 for discharging the reaction product after the source gas has reacted on the surface of the semiconductor wafer W and the like and the residual gas in the reaction chamber 10 to the outside of the reaction chamber 10 at the bottom of the reaction chamber 10. Prepare. The gas discharge unit 26 is connected to a vacuum pump (not shown).

  In the single wafer epitaxial growth apparatus shown in FIG. 1, a wafer inlet / outlet and a gate valve (not shown) for taking in and out a semiconductor wafer are provided at the side wall portion of the reaction chamber 10. The semiconductor wafer W can be transferred by a handling arm between a load lock chamber (not shown) connected by the gate valve and the reaction chamber 10. Here, for example, a handling arm made of synthetic quartz can be inserted into the space between the shower plate 11 and the wafer support 12.

  FIG. 2 is a process flow diagram of the vapor phase growth method of the present embodiment. The vapor phase growth method of this embodiment is performed using the single wafer type epitaxial growth apparatus shown in FIG.

  The vapor phase growth method of the present embodiment includes a first substrate carry-in step (S10), an AlN film formation step (S12), a GaN film (first film) formation step (S14), and a first substrate carry-out step (S16). ), Dummy substrate (second substrate) carry-in step (S18), cleaning step (S20), bake step (S22), AlN film (second film) formation step (S24), second substrate carry-out step (S26) ), Third substrate carry-in step (S28), AlN film (third film) formation step (S30), GaN film (third film) formation step (S32), and third substrate carry-out step (S34). I have.

  First, a first wafer whose surface is (111) silicon (Si) is carried into the reaction chamber 10 (S10). The first wafer is, for example, a silicon wafer. The first wafer is an example of a first substrate. For example, a gate valve (not shown) at the wafer entrance / exit of the reaction chamber 10 is opened and the first wafer in the load lock chamber is transferred into the reaction chamber 10 by a handling arm.

  Then, the first wafer is placed on the support portion 12 using, for example, push-up pins (not shown). The handling arm is returned to the load lock chamber and the gate valve is closed.

  Then, a vacuum pump (not shown) is operated to exhaust the gas in the reaction chamber 10 from the gas discharge unit 26, so that the inside of the reaction chamber 10 has a predetermined degree of vacuum. At this time, the heating output of the heating unit 16 is increased to keep the temperature of the first wafer at the preheating temperature.

  Thereafter, the heating output of the heating unit 16 is increased to raise the temperature of the first wafer to a baking temperature, for example, 1000 ° C. or higher and 1100 ° C. or lower. The temperature of the first wafer is measured by, for example, a radiation thermometer.

  Then, baking (annealing) before film formation is performed while continuing the exhaust by the vacuum pump and rotating the rotator unit 14 at a required speed. By baking, for example, the natural oxide film on the first wafer is removed, and Si is exposed on the surface.

  At the time of baking, for example, hydrogen gas is supplied to the reaction chamber 10 through the gas supply unit 13. After baking for a predetermined time, for example, the heating output of the heating unit 16 is lowered to lower the temperature of the first wafer to an epitaxial growth temperature, for example, 950 ° C. or higher and 1050 ° C. or lower.

  Then, process gas is supplied from the gas supply unit 13 into the reaction chamber 10 through the shower plate 11. By supplying the process gas, an aluminum nitride (AlN) film is formed on the Si surface of the first wafer by epitaxial growth (S12). The film thickness of the AlN film is, for example, not less than 100 nm and not more than 300 nm.

The process gas is, for example, a gas obtained by diluting trimethylaluminum (TMA) with hydrogen gas (H ₂ ) and ammonia (NH ₃ ). Trimethylaluminum (TMA) is a source gas of aluminum (Al), and ammonia (NH ₃ ) is a source gas of nitrogen (N).

  Note that a silicon nitride (SiN) film can be used instead of the aluminum nitride (AlN) film.

  Next, process gas (first gas) is supplied from the gas supply unit 13 into the reaction chamber 10 through the shower plate 11. By supplying the process gas, a gallium nitride (GaN) film is formed on the surface of the AlN film of the first wafer by epitaxial growth (S14). The GaN film is an example of a first film.

The process gas includes a source gas containing gallium (Ga). The process gas is, for example, a gas obtained by diluting trimethylgallium (TMG) with hydrogen gas (H ₂ ) and ammonia (NH ₃ ). Trimethylgallium (TMG) is a gallium (Ga) source gas, and ammonia (NH ₃ ) is a nitrogen (N) source gas.

  When forming the GaN film on the first wafer, deposits containing Ga also adhere to portions other than the first wafer in the reaction chamber 10. The deposit containing Ga adheres to, for example, a member surface in the reaction chamber 10 or an inner wall of the reaction chamber 10.

  The deposit containing Ga is, for example, a reaction product containing Ga. In particular, a reaction product containing Ga may adhere to a region of the support 12 where the reaction is promoted at a high temperature that is not covered with the wafer. The reaction product containing Ga is, for example, GaN. Moreover, the deposit containing Ga is, for example, an adsorbent of a gas containing Ga.

  Note that the film formed as the first film is not limited to the GaN film as long as the film is formed by supplying a source gas containing gallium (Ga). For example, an InGaN (indium gallium nitride) film, an AlGaN (aluminum gallium nitride) film, a GaAs (gallium arsenide) film, or the like may be used.

  At the end of epitaxial growth, the supply of process gas from the gas supply unit 13 is stopped, the supply of process gas onto the first wafer is interrupted, and the growth of the GaN single crystal film is completed.

  After film formation, the temperature of the first wafer starts to be lowered. First, the rotation of the rotating body unit 14 is stopped. The first wafer on which the GaN single crystal film is formed is placed on the support unit 12, and the heating output of the heating unit 16 is lowered so that the temperature of the first wafer is lowered to the preheating temperature. To do.

  After the temperature of the first wafer is stabilized at a predetermined temperature, for example, the first wafer is detached from the support portion 12 by a push-up pin. Then, the gate valve is opened again, and the handling arm is inserted between the shower plate 11 and the support portion 12. Then, the first wafer is placed on the handling arm. Then, by returning the handling arm on which the first wafer is placed to the load lock chamber, the first wafer is carried out of the reaction chamber 10 (S16).

  Next, for example, a silicon carbide (SiC) dummy wafer is carried into the reaction chamber 10 in the same procedure as the first wafer (S18). The dummy wafer is an example of a dummy substrate (second substrate).

  Then, a vacuum pump (not shown) is operated to exhaust the gas in the reaction chamber 10 from the gas discharge unit 26, so that the inside of the reaction chamber 10 has a predetermined degree of vacuum. Thereafter, the heating output of the heating unit 16 is increased, and the temperature of the dummy wafer is raised to a cleaning temperature, for example, from 950 ° C. to 1050 ° C.

  Next, cleaning is performed by supplying a cleaning gas (second gas) containing chlorine atoms into the reaction chamber 10 (S20). By cleaning, deposits containing Ga adhering to the member surface in the reaction chamber 10 and the inner wall of the reaction chamber 10 are removed.

The cleaning gas containing chlorine atoms is, for example, hydrochloric acid gas (hydrogen chloride: HCl) diluted with hydrogen gas (H ₂ ). The cleaning gas containing chlorine atoms may be other gases such as chlorine gas (Cl ₂ ) diluted with hydrogen gas (H ₂ ). For example, the flow rate of hydrochloric acid gas is 5% to 15% of the flow rate of hydrogen gas.

  The temperature of the dummy wafer (second substrate) during cleaning is desirably 950 ° C. or higher and 1050 ° C. or lower. If it is less than the above range, the deposit containing Ga may not be sufficiently removed. Further, if the above range is exceeded, the surface of the member in the reaction chamber 10 and the inner wall of the reaction chamber 10 may be damaged by the cleaning gas.

  At the end of cleaning, supply of the cleaning gas from the gas supply unit 13 is stopped. Then, the heating output of the heating unit 16 is increased, and the temperature of the dummy wafer is increased to a baking temperature, for example, from 1050 ° C. to 1200 ° C.

  Then, baking (annealing) is performed while continuing the evacuation by the vacuum pump and rotating the rotator unit 14 at a required speed (S22). At the time of baking, a baking gas (third gas) is supplied from the gas supply unit 13 through the shower plate 11 to the reaction chamber 10.

  During cleaning, deposits containing chlorine atoms may adhere to the surface of the member in the reaction chamber 10, the inner wall of the reaction chamber 10, or the piping. The deposit containing a chlorine atom is, for example, a reaction product containing a chlorine atom or an adsorbent of a gas containing a chlorine atom.

  Bake removes deposits containing chlorine atoms adhering to the surface of the member in the reaction chamber 10, the inner wall of the reaction chamber 10, and the piping.

  The baking gas is preferably hydrogen gas from the viewpoint of removing deposits containing Ga in addition to deposits containing chlorine atoms. However, it is also possible to use an inert gas such as nitrogen gas instead of hydrogen gas.

  The temperature of the dummy wafer (second substrate) during baking is preferably 1050 ° C. or higher and 1200 ° C. or lower. If it is below the above range, the deposit containing chlorine atoms may not be sufficiently removed. Moreover, if it exceeds the above range, the dummy wafer may be damaged.

  The temperature of the dummy wafer (second substrate) when supplying the baking gas (third gas) is higher than the temperature of the dummy wafer (second substrate) when supplying the cleaning gas (second gas). Is desirable. By making the baking temperature higher than the cleaning temperature, the effect of removing deposits containing chlorine atoms is increased. Further, when the baking gas is hydrogen gas, the effect of removing deposits containing Ga is increased.

  After baking for a predetermined time, for example, the heating output of the heating unit 16 is lowered to lower the temperature of the dummy wafer to an epitaxial growth temperature, for example, 950 ° C. or higher and 1050 ° C. or lower.

  Next, process gas is supplied from the gas supply unit 13 into the reaction chamber 10 through the shower plate 11. By supplying the process gas, an aluminum nitride (AlN) film is formed on the surface of the dummy wafer by epitaxial growth (S24). The aluminum nitride (AlN) film is an example of the second film.

  The surface of the adhering material containing chlorine atoms adhering to the surface of the member in the reaction chamber 10 and the inner wall of the reaction chamber 10 that could not be removed by baking is covered with the AlN film. A silicon nitride (SiN) film can be applied as the second film.

  The thickness of the AlN film is desirably 10 nm or more and 50 nm or less. If it falls below the above range, the deposit containing chlorine atoms may not be sufficiently covered. If the above range is exceeded, the film formation time of the AlN film becomes long, and the proportion of the crazing process time using the dummy wafer in the total film formation time increases, which may deteriorate the film formation throughput. .

  In particular, from the viewpoint of shortening the craving time using the dummy wafer, the thickness of the AlN film (second film) formed on the dummy wafer (second substrate) is the same as that of the first wafer (first substrate). It is desirable that the thickness is smaller than the thickness of the formed AlN film.

  Thereafter, the dummy wafer (second substrate) is carried out of the reaction chamber 10 in the same procedure as the first wafer (S26).

  Next, a second wafer (third substrate) whose surface is (111) silicon (Si) is carried into the reaction chamber 10 (S28). The second wafer is, for example, a silicon wafer. The second wafer is an example of a third substrate. The second wafer is carried into the reaction chamber 10 in the same manner as the first wafer.

  Thereafter, an AlN film (third film) and a GaN film are formed on the Si surface of the second wafer by the same method as that for the first wafer.

  First, a vacuum pump (not shown) is operated to exhaust the gas in the reaction chamber 10 from the gas discharge unit 26, and the reaction chamber 10 is brought to a predetermined degree of vacuum. Thereafter, the heating output of the heating unit 16 is increased to raise the temperature of the second wafer to a baking temperature, for example, 1000 ° C. or higher and 1100 ° C. or lower.

  Then, baking (annealing) before film formation is performed while continuing the exhaust by the vacuum pump and rotating the rotator unit 14 at a required speed. By this baking, for example, the natural oxide film on the second wafer is removed, and Si is exposed on the surface.

  At the time of baking, for example, hydrogen gas is supplied to the reaction chamber 10 through the gas supply unit 13. After baking for a predetermined time, for example, the heating output of the heating unit 16 is lowered to lower the temperature of the second wafer to an epitaxial growth temperature, for example, 950 ° C. or higher and 1050 ° C. or lower.

  Then, process gas is supplied from the gas supply unit 13 into the reaction chamber 10 through the shower plate 11. By supplying the process gas, an AlN (aluminum nitride) film as a third film is formed on the Si surface of the second wafer by epitaxial growth (S30). The film thickness of the AlN film is, for example, not less than 100 nm and not more than 300 nm.

  Note that a silicon nitride (SiN) film can be used instead of the aluminum nitride (AlN) film.

  The film thickness of the AlN film (third film) formed on the second wafer (third substrate) is thicker than the film thickness of the AlN film (second film) formed on the dummy wafer (second substrate). It is desirable. In other words, the thickness of the AlN film (second film) formed on the dummy wafer (second substrate) is the same as that of the AlN film (third film) formed on the second wafer (third substrate). It is desirable to be thinner. By thinning the AlN film formed on the dummy wafer, it is possible to shorten the time for the craning process using the dummy wafer.

  Next, process gas is supplied from the gas supply unit 13 into the reaction chamber 10 through the shower plate 11. By supplying the process gas, a gallium nitride (GaN) film is formed on the surface of the AlN film of the second wafer by epitaxial growth (S32).

  Thereafter, the second wafer is carried out of the reaction chamber 10 in the same procedure as the first wafer (S34).

  For example, by repeating the steps corresponding to S18 to S34 after the step of S34, it becomes possible to grow a single-crystal GaN film on three or more silicon wafers.

  Next, the operation and effect of the vapor phase growth method of the present embodiment will be described.

  In this embodiment, after a source gas (first gas) containing gallium (Ga) is supplied to the reaction chamber to form a film on the first wafer, the first wafer is unloaded and the gas is discharged. Cleaning is performed while heating the support 12 and the like of the phase growth apparatus. Cleaning is performed using a cleaning gas containing chlorine atoms.

  By performing the cleaning, deposits attached to the surface of the member in the reaction chamber 10 and the inner wall of the reaction chamber 10 are removed during the film formation of the first wafer. This deposit includes Ga (gallium) that is flowed as a process gas during the film formation of the first wafer.

  When deposits containing Ga are attached to the surface of the member in the reaction chamber 10 or the inner wall of the reaction chamber 10, in the temperature rising process of the next film formation in the reaction chamber 10, When Ga or a Ga compound reacts, there is a risk that irregularities and holes are formed on the substrate. For this reason, it becomes difficult to form a high-quality film on the substrate.

  According to the present embodiment, by removing the deposit containing Ga, when the third film is formed on the second wafer after cleaning, the Ga that was present as the deposit is second Reaction with Si on the wafer surface is avoided. Therefore, a high-quality film can be formed on the second wafer.

  However, when the reaction chamber 10 is cleaned using a cleaning gas containing chlorine atoms, the chlorine atoms contained in the cleaning gas are attached to the surface of the members in the reaction chamber 10 or the reaction chamber 10 as deposits containing chlorine atoms. There is a risk of remaining on the inner walls and pipes. Then, when the chlorine atoms later form an AlN film or the like, there is a possibility that the chlorine atoms aggregate at the interface between the wafer and the AlN film or the like.

  If chlorine atoms are present at the interface, the quality of the AlN film or GaN film formed on the wafer may be deteriorated. In addition, when a semiconductor device is manufactured using a wafer on which an AlN film, a GaN film, or the like is formed, chlorine atoms may deteriorate the characteristics of the semiconductor device.

  According to this embodiment, after cleaning, baking using a baking gas is performed. Bake removes deposits containing chlorine atoms adhering to the surface of the member in the reaction chamber 10, the inner wall of the reaction chamber 10, and the piping. Therefore, the chlorine atoms are prevented from aggregating at the interface between the wafer and the AlN film when the AlN film or the like is formed later.

  Further, deposits containing chlorine atoms attached to the surface of the member in the reaction chamber 10 and the inner wall of the reaction chamber 10 that could not be removed by baking are covered with an aluminum nitride (AlN) film. Therefore, when chlorine atoms later form an AlN film or the like, it is suppressed from mixing into the atmosphere, and the chlorine atoms are further suppressed from aggregating at the interface between the wafer and the AlN film or the like.

  As described above, according to the present embodiment, it is possible to provide a vapor phase growth method for forming a high-quality film on Si in the same reaction chamber in which a gas containing Ga is supplied.

(Second Embodiment)
The vapor phase growth method of the present embodiment is the same as the first method except that the fourth gas containing ammonia is supplied to the reaction chamber after the third gas is supplied and before the second film is formed. This is the same as the embodiment. Hereinafter, the description overlapping with the first embodiment will be omitted.

  FIG. 3 is a process flow diagram of the vapor phase growth method of the present embodiment. The vapor phase growth method of this embodiment is performed using the single wafer type epitaxial growth apparatus shown in FIG.

  In addition to the process flow of the vapor phase growth method of the first embodiment shown in FIG. 2, an ammonia supply step (S40) between the baking step (S22) and the AlN film (second film) formation step (S24). ).

  The process up to the bake step (S22) is the same as in the first embodiment. After baking, ammonia (fourth gas) is supplied from the gas supply unit 13 into the reaction chamber 10 (S40). After supplying ammonia for a predetermined time, the supply of ammonia is stopped.

  The temperature of the dummy wafer when ammonia is supplied is, for example, 950 ° C. or higher and 1050 ° C. or lower.

  Thereafter, the process of forming the AlN film (second film) on the dummy wafer (second substrate) is the same as in the first embodiment.

  According to the present embodiment, deposits containing chlorine atoms adhering to the surface of the member in the reaction chamber 10, the inner wall of the reaction chamber 10, or the piping, which could not be removed even by baking, are added to the reaction chamber 10 with ammonia. By supplying, it becomes possible to remove. The chlorine atom in the deposit is, for example, reacted with ammonia to become ammonium chloride, which is removed by decomposition and sublimation of ammonium chloride. Therefore, it is possible to form a higher quality film on the wafer.

  The embodiments of the present invention have been described above with reference to specific examples. The above embodiment is merely given as an example and does not limit the present invention. Moreover, you may combine the component of each embodiment suitably.

  In the embodiment, the film formed after the cleaning in the reaction chamber after the film formation using the source gas containing gallium (Ga) has been described by taking the AlN film and the GaN film as examples. However, the present invention is not limited to this, and any other film may be used as long as it is a film formed on the Si surface. This is because the deposit containing Ga in the reaction chamber may be exposed to the reaction chamber atmosphere by heating in the reaction chamber and react with the Si surface regardless of the type of film deposited on Si.

  In the embodiment, the vertical single-wafer type epitaxial apparatus for forming a film for each wafer has been described as an example. However, the vapor phase growth apparatus is not limited to the single-wafer type epitaxial apparatus. For example, the present invention can also be applied to a planetary CVD apparatus that forms films on a plurality of wafers that revolve and revolve, a horizontal epitaxial apparatus, and the like.

  In the embodiments, description of the apparatus configuration, the manufacturing method, and the like that are not directly required for the description of the present invention is omitted, but the required apparatus configuration, the manufacturing method, and the like can be appropriately selected and used. In addition, all vapor phase growth methods that include elements of the present invention and that can be appropriately modified by those skilled in the art are included in the scope of the present invention. The scope of the present invention is defined by the appended claims and equivalents thereof.

10 Reaction chamber W Semiconductor wafer (substrate)

Claims (6)

Bring the first substrate into the reaction chamber,
Supplying a first gas containing gallium (Ga) to the reaction chamber to form a first film on the first substrate;
Unloading the first substrate from the reaction chamber;
Carrying a second substrate into the reaction chamber;
Supplying a second gas containing chlorine atoms to the reaction chamber;
Supplying hydrogen gas or an inert gas third gas to the reaction chamber;
Forming a second film of an aluminum nitride film or a silicon nitride film on the second substrate;
Unloading the second substrate from the reaction chamber ;
The temperature of the second substrate when supplying the third gas is higher than the temperature of the second substrate when supplying the second gas;
The vapor phase growth method , wherein the temperature of the second substrate when the second gas is supplied is 950 ° C. or higher and 1050 ° C. or lower . 2. The vapor phase growth method according to claim 1, wherein the temperature of the second substrate when the third gas is supplied is 1050 ° C. or higher and 1200 ° C. or lower. Bring the first substrate into the reaction chamber,
Supplying a first gas containing gallium (Ga) to the reaction chamber to form a first film on the first substrate;
Unloading the first substrate from the reaction chamber;
Carrying a second substrate into the reaction chamber;
Supplying a second gas containing chlorine atoms to the reaction chamber;
Supplying hydrogen gas or an inert gas third gas to the reaction chamber;
Forming a second film of an aluminum nitride film or a silicon nitride film on the second substrate;
Unloading the second substrate from the reaction chamber;
Temperature of the second substrate at the time of supplying the third gas, rather higher than the temperature of the second substrate at the time of supplying the second gas,
The vapor phase growth method , wherein the temperature of the second substrate when the third gas is supplied is 1050 ° C. or higher and 1200 ° C. or lower . After unloading the second substrate from the reaction chamber, a third substrate whose surface is silicon (Si) is loaded into the reaction chamber,
The third of claims 1 to 3 vapor deposition method according to any one claim to form a third film of aluminum nitride film or a silicon nitride film on a substrate. The vapor deposition method according to claim 4, wherein the film thickness of the third film is larger than the film thickness of the second film. The gas according to any one of claims 1 to 5 , wherein a fourth gas containing ammonia is supplied to the reaction chamber after the third gas is supplied and before the second film is formed. Phase growth method.

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