Method of manufacturing semiconductor device

A method of manufacturing a semiconductor device includes processing a substrate accommodated in a process container accommodated in a housing by supplying a process gas onto the substrate; and exhausting the process container using an exhaust system comprising a first exhaust pipe connected to the process container, the first exhaust pipe having circular or oval cross-section perpendicular to an exhausting direction thereof; and a second exhaust pipe connected to the first exhaust pipe, the second exhaust pipe having square or rectangular cross-section perpendicular to the exhausting direction, wherein at least a portion of the second exhaust pipe is disposed within the housing.

FIELD OF THE INVENTION

The present invention relates to a substrate processing apparatus, and more particularly, to a substrate processing apparatus capable of processing a semiconductor silicon wafer.

BACKGROUND

A substrate processing apparatus for manufacturing a capacitor used in a semiconductor device such as a dynamic random access memory (DRAM) on a substrate such as a semiconductor silicon wafer is disclosed in Japanese Patent Application Laid-Open No. 2010-50439.

Recently, semiconductor devices are miniaturized, and a substrate processing apparatus for manufacture the semiconductor devices is required to have a low inside pressure in order to improve gas adsorption characteristics according to the miniaturization. Although it is efficient to increase an exhaust speed of a vacuum pump in order to achieve lower inside pressure, it is also necessary to improve a conductance of the exhaust system due to the variation of the exhaust speed of the substrate processing apparatus being dependent upon the conductance of the exhaust system. However, enlarging the diameter of the conventional exhaust system so as to increase the conductance thereof results in a large footprint of the substrate processing apparatus.

SUMMARY

The present invention is directed to providing a substrate processing apparatus with increased conductance of an exhaust system while preventing or suppressing an increase in footprint thereof, thereby reducing an inner pressure thereof.

According to one aspect of the present invention, there is provided an exhaust unit including a first exhaust pipe connected to a process container configured to accommodate and process a substrate, the first exhaust pipe having circular or oval cross-section perpendicular to an exhausting direction thereof; and a second exhaust pipe connected to the first exhaust pipe, the second exhaust pipe having square or rectangular cross-section perpendicular to the exhausting direction.

According to another aspect of the present invention, there is provided a substrate processing apparatus including a process container configured to accommodate a substrate; a process gas supply system configured to supply a process gas for processing the substrate into the process container; and an exhaust system configured to exhaust the process container, wherein the exhaust system includes: a first exhaust pipe connected to the process container, the first exhaust pipe having circular or oval cross-section perpendicular to an exhausting direction thereof; and a second exhaust pipe connected to the first exhaust pipe, the second exhaust pipe having square or rectangular cross-section perpendicular to the exhausting direction.

According to still another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method including processing a substrate accommodated in a process container by supplying a process gas onto the substrate; and exhausting the process container using an exhaust system including a first exhaust pipe connected to the process container, the first exhaust pipe having circular or oval cross-section perpendicular to an exhausting direction thereof; and a second exhaust pipe connected to the first exhaust pipe, the second exhaust pipe having square or rectangular cross-section perpendicular to the exhausting direction.

According to yet another aspect of the present invention, there is provided a substrate processing apparatus including a process chamber configured to accommodate a plurality of substrates stacked together, a process gas supply unit configured to supply a process gas for processing the plurality of substrates into the process chamber, and an exhaust unit configured to exhaust the process chamber. The exhaust unit includes a vacuum pump, and exhaust pipes configured to connect the process chamber and the vacuum pump. At least a portion of the exhaust pipes has a rib structure and includes pipes in which cross-sections perpendicular to an exhaust direction have rectangular or oval shaped portions

DETAILED DESCRIPTION

Hereinafter, a substrate processing apparatus according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. In one embodiment, the substrate processing apparatus is configured as a semiconductor manufacturing apparatus to perform a film forming process as a substrate processing process used in a method of manufacturing an integrated circuit (IC) as a semiconductor device. In addition, in the following disclosure, a case in which a batch-type vertical apparatus is used as a substrate processing apparatus (hereinafter also referred to simply as a ‘processing apparatus’) to perform oxidation, nitridation, diffusion, or chemical vapor deposition (CVD) on a substrate will be described.

Referring toFIG. 1, in a substrate processing apparatus101, a cassette110accommodating a substrate, e.g., a wafer200, is used, and the wafer200is made of semiconductor silicon or the like. The substrate processing apparatus101includes a housing111, and a cassette stage114is installed in the housing111. The cassette110is loaded onto or unloaded from the cassette stage114by a carrying device (not shown) during a process.

The cassette110is placed on the cassette stage114by the carrying device in a manner that the wafer200in the cassette110is retained in a vertical posture and a wafer entrance of the cassette110is disposed upward. The cassette stage114is configured in a manner that the cassette110is vertically rotated 90° toward the rear of the housing111to arrange the wafer200in the cassette110to have a horizontal posture, thereby allowing the wafer entrance of the cassette110to face the rear of the housing111.

A cassette shelf105is installed approximately at a center of the housing111with respect to a forward-backward direction. The cassette shelf105includes a plurality of columns and a plurality of rows to store the cassettes110therein. In the cassette shelf105, a transfer shelf123is installed to accommodate the cassette110that is to be carried via a wafer transfer mechanism125.

A preparatory cassette shelf107is installed above the cassette stage114to preparatorily store the cassette110.

A cassette carrying device118is installed between the cassette stage114and the cassette shelf105. The cassette carrying device118includes a cassette elevator118athat is movable upward/downward while retaining the cassette110, and a cassette carrying mechanism118bas a carrying mechanism. The cassette carrying device118is configured in a manner that the cassette110is carried among the cassette stage114, the cassette shelf105, the preparatory cassette shelf107and the transfer shelf123through an association with the cassette elevator118aand the cassette carrying mechanism118b.

The wafer transfer mechanism125is installed at the rear of the cassette shelf105. The wafer transfer mechanism125includes a wafer transfer device125athat can rotate the wafer200horizontally or move the wafer200in a straight direction, and a wafer transfer device elevator125bthat moves the wafer transfer device125aupward/downward. Tweezers125care installed on the wafer transfer device125ato pick up and retain the wafer200in a horizontal posture. The wafer transfer device125ais configured in a manner that the wafer200is loaded (charged) into a boat217from the cassette110on the transfer shelf123or is unloaded (discharged) from the boat217to be accommodated in the cassette110on the transfer shelf123using the tweezers125cas a unit for placing the wafer200through an association with the wafer transfer device125aand the wafer transfer device elevator125b.

A process furnace202is installed on an upper portion of a rear part of the housing111to thermally treat the wafer200, and a lower end of the process furnace202is configured to be opened and closed by a furnace port shutter147.

A boat elevator115is installed below the process furnace202to move the boat217upward/downward with respect to the process furnace202. A platform of the boat elevator115is connected to an arm128, and a seal cap219is installed parallel to the arm128. The seal cap219is configured to vertically support the boat217and block the lower end of the process furnace202.

The boat217includes a plurality of retaining members, and is configured to horizontally retain a plurality of wafers200(e.g., about 50 to 150 wafers) in a state where the plurality of wafers200are concentrically arranged in a vertical direction.

A cleaning unit134athat supplies clean air (clean atmosphere) is installed above the cassette shelf105. The cleaning unit134aincludes a supply fan (not shown) and a dust filter (not shown), and is configured to circulate clean air within the housing111.

A cleaning unit134bthat supplies clean air is installed at a left end of the housing111. The cleaning unit134balso includes a supply fan (not shown) and a dust filter (not shown), and is configured to circulate clean air near the wafer transfer device125a, the boat217, or the like. The clean air is circulated near the wafer transfer device125aor the boat217and is then exhausted from the housing111.

The housing111includes rear parts301and302at a rear side thereof. A space between the rear parts301and302is used as a maintenance space303for maintenance of the substrate processing apparatus101.

A main operation of the substrate processing apparatus101will now be described.

When the cassette110is loaded onto the cassette stage114by the carrying device (not shown), the cassette110is placed on the cassette stage114in a manner that the wafer200is retained on the cassette stage114in a vertical posture and the wafer entrance of the cassette110faces upward. The cassette110is then vertically rotated 90° toward the rear of the housing111by the cassette stage114such that the wafer200in the cassette110is disposed in a horizontal posture and the wafer entrance of the cassette110faces the rear of the housing111.

Thereafter, the cassette110is automatically carried to a predetermined shelf position at the cassette shelf105or the preparatory cassette shelf107by the cassette carrying device118, is temporarily stored at the predetermined shelf position, and is then transferred to the transfer shelf123from the cassette shelf105or the preparatory cassette shelf107by the cassette carrying device118or is directly carried to the transfer shelf123.

When the cassette110is transferred to the transfer shelf123, the wafer200is picked up from the cassette110via the wafer entrance of the cassette110using the tweezers125cof the wafer transfer device125a, and is loaded (charged) into the boat217through an association with the wafer transfer device125aand the wafer transfer device elevator125b. The wafer transfer device125athat transfers the wafer200to the boat217is returned to the cassette110so as to load a subsequent wafer200into the boat217.

When a predetermined number of the wafers200are loaded into the boat217, the furnace port shutter147that blocks the lower end of the process furnace202is opened to expose the lower end of the process furnace202. The boat217retaining the predetermined number of the wafers200is then loaded into the process furnace202by a lifting movement of the boat elevator115, and the lower end of the process furnace202is blocked by the seal cap219.

After the boat217is loaded, a predetermined treatment is performed on the wafers200in the process furnace202. Thereafter, the wafers200and the cassette110are unloaded from the housing111in reverse order.

The process furnace202used in the substrate processing apparatus101described above will now be described with reference toFIG. 2.

Referring toFIG. 2, a heater207which is a heating device (heating means) for heating the wafers200is installed in the process furnace202. The heater207includes a cylindrical insulating member with the top being closed and a plurality of heater wires, and has a unit structure in which the plurality of heater wires are installed with respect to the insulating member. The heater207is installed vertically while being supported by a heater base (not shown) as a retaining plate. In addition, a heating power source (not shown) that supplies power to the heater207is installed. Inside the heater207, a reaction tube203made of quartz forming a reaction container (process container) for processing the wafer200is installed concentrically with the heater207.

The seal cap219is installed below the reaction tube203as a furnace port lid capable of air-tightly sealing an aperture in a lower end of the reaction tube203. The seal cap219is configured to vertically abut the lower end of the reaction tube203. The seal cap219is made of a metal such as stainless steel, and has a disc shape. A sealing member (hereinafter referred to as an ‘O-ring’)220is disposed between a ring-shaped flange installed on an end of the aperture in the lower end of the reaction tube203and an upper surface of the seal cap219to air-tightly seal the ring-shaped flange and the upper surface of the seal cap219. At least the reaction tube203and the seal cap219forms a process chamber201.

A boat support218supporting the boat217is installed on the seal cap219. The boat support218is made of a heat-resistant material such as quartz or silicon carbide, and functions as both an insulating member and a supporting member. The boat217is made of a heat-resistant material such as quartz or silicon carbide. The boat217includes a bottom board210fixed onto the boat support218, a top board211disposed above the bottom board210and a plurality of pillars212installed between the bottom board210and the top board211(seeFIG. 1). The plurality of wafers200are retained in the boat217. The plurality of wafers200are stacked in multistage and arranged concentrically in a tube axial direction of the reaction tube203, and supported by the pillars212of the boat217while the wafers200are retained at predetermined intervals and in a horizontal posture.

A rotation mechanism267that rotates the boat217is installed at a side of the seal cap219opposite to the process chamber201. A rotation shaft255of the rotation mechanism267is connected to the boat support218through the seal cap219, and rotates the plurality of wafers200by rotating the boat217via the boat support218by the rotation mechanism267so as to improve uniformity of substrate processing.

The seal cap219can be moved upward or downward by the boat elevator115which is a lifting mechanism installed outside the reaction tube203, thereby loading the boat217into or unloading the boat217from the process chamber201.

The boat217supported by the boat support218is loaded into the process chamber218while the plurality of wafers200to be batch-processed are stacked in multistage with respect to the boat217. The process furnace202is configured in a manner that the plurality of wafers200inserted into the process chamber201are heated to a predetermined temperature by the heater207.

In the process chamber201, a nozzle249aand a nozzle249bare installed below the reaction tube203to pass through the reaction tube203. The nozzles249aand249bare connected to a gas supply pipe232aand a gas supply pipe232b, respectively. The two nozzles249aand249band the two gas supply pipes232aand232bare installed in the reaction tube203so that a plurality of types of gases may be supplied into the process chamber201. In addition, as will be described below, the gas supply pipe232aand the gas supply pipe232bare connected to an inert gas supply pipe232eand an inert gas supply pipe232f, respectively.

A mass flow controller (MFC)241awhich is a flow rate controller (flow rate control unit), a vaporizer271awhich is a vaporizing device (vaporizing means) for generating a vapor gas as a source gas by vaporizing a liquid source, and a valve243awhich is a opening/closing valve are sequentially installed at the gas supply pipe232afrom an upstream side to a downstream side. The vapor gas generated in the vaporizer271ais supplied into the process chamber201via the nozzle249aby opening the valve243a. A vent line232iconnected to an exhaust pipe247which will be described later is connected to the gas supply pipe232abetween the vaporizer271aand the valve243a. A valve243iwhich is a opening/closing valve is installed in the vent line232ito supply a source gas to the vent line232ivia the valve243iwhen the source gas is not supplied into the process chamber201. The supply of the vapor gas into the process chamber201may be discontinued while continuously generating the vapor gas by the vaporizer271aby closing the valve243aand opening the valve243i. Although it takes considerable time to safely generate the vapor gas, it may take a very short time to switch between supplying the vapor gas into the process chamber201and discontinuing the supply of the vapor gas by opening and closing the valve243aand the valve243i. In addition, the inert gas supply pipe232eis connected to the gas supply pipe232aat a downstream side of the valve243a. An MFC241ewhich is a flow rate controller (flow rate control unit) and a valve243ewhich is a opening/closing valve are sequentially installed at the inert gas supply pipe232efrom an upstream side to a downstream side.

The nozzle249adescribed above is connected to a front end of the gas supply pipe232a. The nozzle249ais installed in an arc-shaped space between an inner wall of the reaction tube203and the wafers200and extends from a lower portion to an upper portion of the inner wall of the reaction tube203in a stacking direction. The nozzle249amay be an L-shaped long nozzle. Gas supply holes250aare disposed on a side surface of the nozzle249ato supply a gas. The gas supply holes250aare open toward a center of the reaction tube203. The gas supply holes250aare disposed from the lower portion to the upper portion of the reaction tube203, and have the same opening area and the same pitch.

The gas supply pipe232a, the vent line232i, the valves243aand243i, the vaporizer271a, the MFC241aand the nozzle249aconstitutes a first gas supply system. In addition, the inert gas supply pipe232e, the MFC241eand the valve243econstitutes a first inert gas supply system.

An ozonizer500which generates ozone (O3) gas, a valve243c, an MFC241bwhich is flow rate controller (flow rate control unit), and a valve243bwhich is a opening/closing valve are sequentially installed at the gas supply pipe232bto an upstream side to a downstream side. An upstream side of the gas supply pipe232bis connected to an oxygen gas supply source (not shown) that supplies oxygen (O2) gas. Oxygen (O2) gas supplied to the ozonizer500is changed into ozone (O3) gas by the ozonizer500and then supplied into the process chamber201. A vent line232hconnected to the exhaust pipe247which will be described later is connected to the gas supply pipe232bbetween the MFC241band the valve243b. A valve243hwhich is a opening/closing valve is installed at the vent line232hto supply a source gas into the vent line232hvia the valve243hwhen the ozone (O3) gas is not supplied into the process chamber201. By closing the valve243band opening the valve243h, the supply of the ozone (O3) gas into the process chamber201may be discontinued while the ozone (O3) gas is continuously generated by the ozonizer500. Although it takes considerable time to safely refine the ozone (O3) gas, it may take a very short time to switch between supplying the ozone (O3) gas into the process chamber201and discontinuing the supply of the ozone (O3) gas by opening and shutting the valve243band the valve243h. In addition, the inert gas supply pipe232fis connected to the gas supply pipe232bat a downstream side of the valve243b. An MFC241fwhich is a flow rate controller (flow rat control unit) and a valve243fwhich is a opening/closing valve are sequentially installed at the inert gas supply pipe232ffrom an upstream side to a downstream side.

The nozzle249bdescribed above is connected to a front end of the gas supply pipe232b. The nozzle249bis installed in an arc-shaped space between an inner wall of the reaction tube203and the wafers200and extends from a lower portion to an upper portion of the inner wall of the reaction tube203in a stacking direction. The nozzle249bmay be an L-shaped long nozzle. Gas supply holes250bare disposed on a side surface of the nozzle249bto supply a gas. The gas supply holes250bare open toward the center of the reaction tube203. The gas supply holes250bare disposed from the lower portion to the upper portion of the reaction tube203, and have the same opening area and the same pitch.

The gas supply pipe232b, the vent line232h, the ozonizer500, the valves243c,243b,and243h, the MFC241band the nozzle249bconstitutes a second gas supply system. In addition, the inert gas supply pipe232f, the MFC241fand the valve243fconstitutes a second inert gas supply system.

A zirconium source gas, i.e., a gas containing zirconium (Zr) (zirconium-containing gas) is supplied as a source gas into the process chamber201via the gas supply pipe232a, the MFC241a, the vaporizer271a, the valve243aand the nozzle249a. For example, tetrakis(ethylmethylamino)zirconium (TEMAZ) gas may be used as the zirconium-containing gas. In addition, the source gas may be in a solid, liquid or gaseous state at a room temperature and atmospheric pressure. However, the source gas is assumed to be in the liquid state hereinafter. When the source gas is in the gaseous state at the room temperature and atmospheric pressure, the vaporizer500is not required.

A gas containing oxygen (O) (oxygen-containing gas) such as oxygen (O2) gas is supplied to the gas supply pipe232b, changed into ozone (O3) gas by the ozonizer500, and then supplied as an oxidizing gas (oxidizing agent) into the process chamber201via the valve243c,the MFC241b, the valve243band the nozzle249b. Alternatively, the oxygen (O2) gas may be supplied as the oxidizing gas into the process chamber201without generating the ozone (O3) gas by the ozonizer500.

Nitrogen (N2) gas, for example, is supplied into the process chamber201via the inert gas supply pipes232eand232f, the MFCs241eand241f, the valves243eand243f, the gas supply pipes232aand232band the nozzles249aand249b.

In the reaction tube203, a temperature sensor263is installed as a temperature detector. The temperature sensor263is configured to control an amount of current to be supplied to the heater207based on temperature information detected by the temperature sensor263so that inside temperature of the process chamber201may have a desired temperature distribution. The temperature sensor263has an L-shape similar to the nozzles249aand249b, and is installed along the inner wall of the reaction tube203.

An exhaust system300is installed in the reaction tube203to exhaust the atmosphere in the process chamber201. An exhaust pipe231, an auto pressure controller (APC) valve244which is a pressure adjustor (pressure adjustment unit), an exhaust pipe320, an exhaust pipe330, an exhaust pipe340, a vacuum pump246which is a vacuum exhaust device and the exhaust pipe247are sequentially installed at the exhaust system300from an upstream side (a process chamber side) to a downstream side. A pressure sensor245is installed as a pressure detector (pressure detection unit) at the exhaust pipe231to detect inside pressure of the process chamber201. The exhaust pipe247installed at a downstream side of the vacuum pump246is connected to a waste gas processing device (not shown). The exhaust system300is configured to vacuum-exhaust an inside of the process chamber201such that inside pressure of the process chamber201is at a predetermined pressure (degree of vacuum). The APC valve243is a opening/closing valve configured to start or suspend the vacuum-exhaust of the process chamber201by opening/closing, and to adjust the pressure in the process chamber201by controlling the degree of opening and a conductance thereof

A controller121which is a control unit (control member) is connected to the MFCs241a,241b,241eand241f, the valves243a,243b,243c,243e,243f,243h, and243i, the vaporizer271a, the ozonizer500, the pressure sensor245, the APC valve244, the vacuum pump246, the heating power source (not shown), the temperature sensor263, the boat rotation mechanism267and the boat elevator115. The controller121controls flow rates of various gases by controlling the MFCs241a,241b,241eand241f;controls opening/closing of the valves243a,243b,243c,243e,243f,243hand243i;controls opening/closing of the APC valve244; controls the degree of pressure using the pressure sensor245; controls temperature of the heater207using the temperature sensor263; controls the vaporizer271aand the ozonizer500; controls driving/suspending of the vacuum pump246; controls a rotation speed of the boat rotation mechanism267; and controls a lifting operation of the boat elevator115.

The exhaust system300will now be described in more detail. As described above, the exhaust pipe231, the APC valve244, the exhaust pipe320, the exhaust pipe330, the exhaust pipe340, the vacuum pump246and the exhaust pipe247are sequentially installed in the exhaust system300from the upstream side (process chamber side) to the downstream side of the exhaust system300. Referring toFIG. 4, the exhaust pipes231,320,340and247are round pipes each having a circular cross-section. Exhaust pipes331through334are sequentially installed at the exhaust pipe330, from the upstream side to the downstream side of the exhaust pipe330.

The exhaust pipes331through333have the same lateral cross-sections and are vertically stacked. The exhaust pipes331to333are rectangular-shaped pipes having rectangular cross-sections. Thus, even when the conductances of the exhaust pipes331through333increases by increasing the lateral cross-sectional areas thereof, the exhaust pipes331through333may be accommodated in the rear part302of the housing111of the substrate processing apparatus101, and the footprint of the substrate processing apparatus101is not expanded (seeFIG. 7). In contrast, when a circular pipe360having a circular cross-section is used and a lateral cross-sectional area of the circular pipe360is increased to increase the conductances thereof, a rear part302′ of the housing111needs to be expanded so as to accommodate the circular pipe360as illustrated inFIG. 8, thereby expanding the footprint of the substrate processing apparatus101. According to the structure of the exhaust system300, in case of supplying N2 at 30 slm, the inside pressure of the substrate processing apparatus may be reduced to several Pas to several tens of Pas when the square-shaped exhaust pipes331through333illustrated inFIG. 7that may be accommodated in the rear part302of the housing111are used, compared to a circular pipe351illustrated inFIG. 9that may be accommodated in the rear part302of the housing111. As described above, by using the rectangular-shaped exhaust pipes331through333, the conductance of the exhaust system300may be improved without increasing the footprint of the substrate processing apparatus101, and the exhaust performance of the vacuum pump246is also improved. As a result, the inside pressure of the substrate processing apparatus101may be reduced without increasing the footprint of the substrate processing apparatus101, and gas adsorption characteristics in regard to miniaturization of semiconductor device may be improved. In addition, the cross-sectional areas of the exhaust pipes331through333are determined by an amount of exhaust (destination pressure in the process chamber201).

As described above, since, according to the present embodiment, the conductance of the exhaust system300may be improved, the amount of exhaust may be increased, and the pressure of the substrate processing apparatus101may be reduced. Therefore, the substrate processing apparatus101according to the present embodiment may be preferably used in an apparatus using a source gas having a low vapor pressure.

In addition, since an apparatus that performs plasma processing requires a low inside pressure, the substrate processing apparatus101according to the present embodiment may be used in the apparatus that performs plasma processing.

Referring toFIG. 5, an aspect ratio (a ratio between height A and width B=A/B) of each of the exhaust pipes331through333may be 8:1 or lower. Such aspect ratio is preferable because a desired destination pressure may be obtained while maintaining a width of the apparatus to be the same as that of a conventional apparatus wherein a circular pipe is used.

In addition, as illustrated inFIG. 5, each of the exhaust pipes331through333may include at least one rib370for reinforcement. The at least one rib370may be installed on inner sides of the exhaust pipes331through333as illustrated inFIG. 5or may be installed on outer sides of the exhaust pipes331through333as illustrated inFIG. 6.

Since the housing111is installed on a floor400of a clean room, the exhaust pipes331through333accommodated in the rear part302of the housing111are also installed on the floor400of the clean room. Although the exhaust pipe334is also a rectangular-shaped exhaust pipe having a rectangular lateral cross-section, the exhaust pipe334is installed below the floor400of the clean room. Thus, the footprint of the substrate processing apparatus101is not directly influenced by the size of the exhaust pipe334. The exhaust pipe340and the vacuum pump246are also installed below the floor400of the clean room. The exhaust pipe247is connected to a waste gas processing apparatus (not shown) installed outdoors via the floor400of the clean MOM.

The process furnace202is not directly connected to the rectangular-shaped exhaust pipe330(exhaust pipes331through333) so that the process furnace202need not be taken out of the substrate processing apparatus101for setup or maintenance.

Although each of the lateral cross-sections of the exhaust pipes331through333is rectangular-shaped, the lateral cross-sections of the exhaust pipes331through333may be square-shaped or L-shaped. In this case, it is preferable that a rib is included on the inner or outer side of each of the exhaust pipes331through333for reinforcement.

Alternatively, exhaust pipes each having an oval cross-section may be used as the exhaust pipes331through333. In this case, a rib may also be included on the inner or outer sides of the exhaust pipes331through333for reinforcement thereof.

As described above, the exhaust pipes331through333having rectangular-shaped or oval-shaped cross-sections perpendicular to an exhaust direction are preferable. In this case, it is preferable that a rib is included in the inner or outer side of each of the exhaust pipes331through333for reinforcement.

Next, a sequence of forming an insulating film, which may be preferably used for a capacitor of a dynamic random access memory (DRAM), on a substrate using the process furnace202of the substrate processing apparatus101described above will be described as a process included in a manufacturing process of a semiconductor apparatus (semiconductor device). In the following disclosure, operations of the elements of the substrate processing apparatus101are controlled by the controller121.

A plurality of types of gases containing elements of a film that are to be formed are simultaneously supplied during chemical vapor deposition (CVD), and are alternately supplied during atomic layer deposition (ALD). A silicon nitride film (SiN film) or a silicon oxide film (SiO film) is formed by controlling supply conditions of a gas such as a gas supply flow rate, a gas supply time and plasma power. In the CVD and the ALD, the supply conditions are controlled such that a composition ratio of the SiN film satisfies (N/Si)≈1.33 which is a stoichiometric composition when the SiN film is formed for example, and that a composition ratio of the SiO film satisfies (O/Si)≈2 which is a stoichiometric composition when the SiO film is formed for example.

Alternatively, the supply conditions may be controlled such that a composition ratio of a film that is to be formed is different from a stoichiometric composition. In other words, the supply conditions may be controlled such that a composition of at least one of the elements of the film is beyond the range of a stoichiometric composition, compared to the other elements. As described above, a film may be formed while controlling a ratio of the elements of the film such as the composition ratio of the film.

A sequence of forming a film (a ZrO2 film) including a stoichiometric composition as a high-k dielectric insulating film for a capacitor of a DRAM by alternately supplying two types of gases, e.g., TEMAZ gas and ozone (O3) gas, which contain two elements, e.g., zirconium (Zr) and oxygen (O), will now be described with reference toFIGS. 10 and 11.

The inside of the process chamber201is maintained at a predetermined temperature, e.g., 150° C. to 250° C., by controlling the heater207.

Thereafter, after the plurality of wafers200are loaded into the boat217(wafer charging) (Step S201), the boat217supporting the plurality of wafers200is lifted by the boat elevator115and then loaded into the process chamber201(boat loading) (Step S202). The lower end of the reaction tube203is in a state of air-tight sealing by the seal cap219via the O-ring220.

Thereafter, the inside of the process chamber201is vacuum-exhausted by the vacuum pump246to a desired pressure (degree of vacuum). The pressure in the process chamber201is measured by the pressure sensor245, and the APC valve244is feedback-controlled based on the measured pressure (Step S203: pressure control). In addition, the inside of the process chamber201is heated to a desired temperature by the heater207. The amount of current supplied to the heater207from the heating power source (not shown) is also feedback-controlled based on temperature information detected by the temperature sensor263so that the inside of the process chamber201has a desired temperature distribution (Step S203: temperature control). Thereafter, the boat217is rotated by the rotation mechanism267, thus rotating the wafers200.

Thereafter, a process of forming a ZrO2 film which is an insulating film by ALD is performed by supplying TEMAZ gas and ozone (O3) gas into the process chamber201. The process of forming the ZrO2 film is performed by sequentially performing the following four steps.

In Step S204, the TEMAZ gas is supplied first. By opening the valve243aof the gas supply pipe232aand closing the valve243iof the vent line232i, the TEMAZ gas is supplied into the gas supply pipe232avia the vaporizer271a. A flow rate of the TEMAZ gas flowing through the gas supply pipe232ais controlled by the MFC241a. The TEMAZ gas having the flow rate thereof controlled is supplied into the process chamber201via the gas supply holes250aof the nozzle249a, and, at the same time, is exhausted via the gas exhaust system300. At the same time, an inert gas such as N2 gas, is supplied into the inert gas supply pipe232eby opening the valve243e. A flow rate of the N2 gas flowing through the inert gas supply pipe232eis controlled by the MFC241e. The N2 gas having the flow rate thereof controlled is supplied into the process chamber201together with the TEMAZ gas and exhausted via the gas exhaust system300.

The pressure in the process chamber201is controlled to range, for example, from 50 to 400 Pa, by appropriately controlling the APC valve244. The supply flow rate of the TEMAZ gas controlled by the MFC241ais controlled to range from 0.1 to 0.5 g/min for example. A time period during which the wafer200is exposed to the TEMAZ gas, i.e., a gas supply time (irradiation time), is set to range from 30 to 240 seconds for example. The temperature of the heater207is set such that the temperature of the wafer200ranges from 150 to 250° C. for example.

By supplying the TEMAZ gas, a layer containing zirconium (Zr) is formed on a surface of the wafer200. That is, a zirconium (Zr) layer may be formed as a zirconium (Zr)-containing layer on the wafer200having a thickness of less than one atomic layer to several atomic layers. The zirconium (Zr)-containing layer may be a chemical adsorption (surface adsorption) layer of the TEMAZ gas. Zirconium (Zr) is an element having only a solid state. Here, examples of the zirconium (Zr) layer may include a continuous layer, a discontinuous layer or a thin film formed by overlapping the continuous layer and the discontinuous layer. The continuous layer including zirconium (Zr) may also be referred to as a thin film. Examples of the chemical adsorption layer of the TEMAZ gas may include not only continuous chemical adsorption layers including gas molecules of the TEMAZ gas but also discontinuous chemical adsorption layers including the gas molecules of the TEMAZ gas. When the thickness of the zirconium (Zr) layer formed on the wafer200exceeds several atomic layers, the oxidization process performed in Step206which will be described later is not delivered to the entire zirconium-containing layer. A minimum thickness of the zirconium-containing layer that may be formed on the wafer200is less than one atomic layer. Thus, the zirconium-containing layer may have a thickness ranging from less than one atomic layer to several atomic layers. In addition, conditions such as the temperature of the wafer200and the inside pressure of the process chamber201may be controlled such that a zirconium (Zr) layer is formed by depositing zirconium (Zr) on the wafer200under conditions where the TEMAZ gas is self-decomposed, and that a chemical adsorption layer of the TEMAZ gas is formed by chemically adsorbing the TEMAZ gas onto the wafer200under conditions where the TEMAZ gas is not self-decomposed. In addition, a film-forming rate of the zirconium (Zr) layer on the wafer200may be higher than that that of the chemical adsorption layer of the TEMAZ gas. In addition, a film may be more densely formed when the zirconium (Zr) layer is formed on the wafer200than when the chemical adsorption layer of the TEMAZ gas is formed on the wafer200.

In Step S205, after the zirconium-containing layer is formed, the valve243ais closed and the valve243iis opened to suspend the supply of the TEMAZ gas into the process chamber201and to flow the TEMAZ gas into the vent line232i. The inside of the process vacuum201is vacuum-exhausted by the vacuum pump246by opening the APC valve244of the gas exhaust system300, thereby removing non-reacted or residual TEMAZ gas remaining in the process chamber201from the process chamber201after the zirconium-containing layer is formed. In addition, N2 gas is continuously supplied into the process chamber201by opening the valve243e. By continuously supplying the N2 gas into the process chamber201, the non-reacted or residual TEMAZ gas remaining in the process chamber201after the zirconium-containing layer is formed may be efficiently removed from the process chamber201. A rare gas such as argon (Ar) gas, helium (He) gas, neon (Ne) gas or xenon (Xe) gas may be used as an inert gas instead of the N2 gas.

In Step S206, after the residual gas is removed from the process chamber201, O2 gas is supplied into the gas supply pipe232b. The O2 gas flowing through the gas supply pipe232bis changed into O3 gas by the ozonizer500. By opening the valves243cand243bof the gas supply pipe232band closing the valve243hof the vent line232h, the O3 gas is supplied into the process chamber via the gas supply holes250bof the nozzle249bwhile controlling a flow rate of the O3 gas flowing through the gas supply pipe232bby the MFC241d, and at the same time, is exhausted via the gas exhaust system300. At the same time, N2 gas is supplied into the inert gas supply pipe232fby opening the valve243f. The N2 gas is supplied into the process chamber201together with the O3 gas, and at the same time, is exhausted via the gas exhaust system300.

When the O3 gas is supplied, the APC valve244is appropriately controlled such that the inner pressure of the process chamber201may range from 50 to 400 Pa for example. A supply flow rate of the O3 gas controlled by the MFC241bmay range from 10 to 20 slm for example. A time period during which the wafer200is exposed to the O3 gas, i.e., a gas supply time (irradiation time), may range from 60 to 300 seconds for example. The temperature of the heater207is set such that the temperature of the wafer200ranges from 150 to 250° C. similar to Step S204.

The gas supplied into the process chamber201is O3 gas and the TEMAZ gas is not supplied into the process chamber201. Thus, the O3 gas reacts with a portion of the zirconium-containing layer formed on the wafer200in Step S204without causing a gaseous reaction. Accordingly, the zirconium-containing layer is oxidized and modified into a layer containing zirconium and oxygen, i.e., a zirconium oxide (ZrO2) layer.

In Step S207, the valve243bof the gas supply pipe232bis closed and the valve243his opened to suspend the supply of the O3 gas into the process chamber201and to supply the O3 gas into the vent line232h. The inside of the process chamber201is vacuum-exhausted by the vacuum pump246by opening the APC valve244of the gas exhaust system300, thereby removing non-reacted or residual O3 gas remaining in the process chamber201from the process chamber201after an oxidization process is performed. In addition, N2 gas is continuously supplied into the process chamber201by opening the valve243fBy continuously supplying the N2 gas into the process chamber201, the non-reacted or residual O3 gas remaining in the process chamber201after the oxidization process is performed may be efficiently removed from the process chamber201. O2 gas may be used as an oxygen-containing gas instead of the O3 gas.

An insulating film containing zirconium and oxygen, i.e., a ZrO2 film, may be formed on the wafer200to a predetermined thickness by performing the cycle including Steps S204through S207at least once (Step S208).

After the formation of the ZrO2 film having the predetermined thickness, the valves243eand valve243fare opened to supply an inert gas such as N2 gas into the inert gas supply pipes232eand232f, and the inside of the process chamber201is purged with the inert gas by exhausting the process chamber201while supplying the inert gas such as the N2 gas, into the process chamber201(gas purging: Step S210). Thereafter, an atmosphere in the process chamber201is replaced with the inert gas (replacement of inert gas), and the pressure in the process chamber201is returned to a atmospheric pressure (atmosphere pressure recovery: Step S212). Thereafter, the seal cap219is moved downward by the boat elevator115to open the lower end of the reaction tube203, and at the same time, the processed wafer200supported by the boat217is unloaded from the process chamber201through the lower end of the reaction tube203(boat unloading: Step S214). Thereafter, the processed wafer200is discharged from the boat217(wafer discharging: Step S216).

According to the present invention, a substrate processing apparatus with the increase conductance of the exhaust system while preventing or suppressing the increase in footprint thereof, thereby reducing the inner pressure thereof

EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

Exemplary embodiments of the present invention are supplementarily noted.

Supplementary Note 1

According to an embodiment of the present invention, a substrate processing apparatus includes a process container configured to accommodate a plurality of substrates; a process gas supply unit configured to supply a process gas into the process container to process the plurality of substrates; and an exhaust unit configured to exhaust the process container. The exhaust unit includes a vacuum pump and exhaust pipes configured to connect the process container and the vacuum pump. At least a portion of the exhaust pipes has a rib structure, and cross-sections of the exhaust pipes perpendicular to an exhaust direction include rectangular or oval shaped portions.

Supplementary Note 2

In the substrate processing apparatus described in Supplementary Note 1, the at least a portion of the exhaust pipes may have a rib structure and cross-sections of the exhaust pipes perpendicular to the exhaust direction may have a rectangular or oval shape.

Supplementary Note 3

In the substrate processing apparatus described in Supplementary Note 1, the at least a portion of the exhaust pipes may have a rib structure, and cross-sections of the exhaust pipes perpendicular to the exhaust direction may have a rectangular shape.

Supplementary Note 4

In the substrate processing apparatus described in Supplementary Note 1, an aspect ratio of the rectangular cross-section may be 8:1 or lower.

Supplementary Note 5

In the substrate processing apparatus described in one of Supplementary Notes 1 through 4, the process gas supply unit is configured to form a high-k dielectric film by alternately supplying two types of process gases into the process container.