JP2005183514A - Method of manufacturing semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase throughput while preventing a decline in selectivity of selective epitaxial growth. <P>SOLUTION: A wafer 200 which has an insulation layer 13 on part of the front surface and has an exposed silicon layer 11 is carried into a treatment chamber (step 101). Disilane gas is supplied into the treatment chamber (step 103). After supplying the disilane gas, chlorine-based gas is supplied into the treatment chamber (step 104). After supplying the chlorine-based gas, hydrogen gas is supplied into the treatment chamber (step 105). By repeating the steps 103, 104, and 105 in order several times, a silicon epitaxial film 12 is grown on the exposed silicon layer 11. The pressure inside the treatment chamber in the step 105 is made larger than that in the step 103 or step 104. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a semiconductor device, and is particularly suitable for selectively growing an epitaxial film on a substrate.

  With the high integration and high performance of MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), the source / drain of MOSFETs are required to reduce leakage current and reduce resistance.

  One method for meeting these requirements is to selectively grow a silicon epitaxial film on the source / drain. As a method for selectively growing a silicon epitaxial film on the silicon layer of a wafer having an insulating layer (silicon nitride film or silicon oxide film) on a part of the surface and exposing the silicon layer, at least one of a silane-based gas and a germane-based gas is used. One is known in which selective gas epitaxial growth is performed by alternately supplying one gas and chlorine gas or fluorine gas (see, for example, Patent Document 1).

However, in Patent Document 1, after supplying chlorine gas or fluorine gas, chlorine or fluorine adheres to the silicon layer exposed on the substrate, and the silane-based gas or germane-based gas is supplied on the substrate in the next step. It inhibits the growth of the silicon film on the exposed silicon layer.
Therefore, in Patent Document 1, chlorine or fluorine adhering to the silicon layer is removed using disilane or monogermane. At this time, disilane or monogermane is also supplied onto the silicon nitride film or silicon oxide film. Is done. On the silicon nitride film or silicon oxide film, there is no influence of chlorine or fluorine on the growth of the silicon film. Therefore, since the silicon film grows on the silicon nitride film or the silicon oxide film while removing chlorine or fluorine adhering to the silicon layer, the selectivity of selectively growing only on the silicon layer is easily broken. . For this reason, Patent Document 1 has a problem of causing a decrease in selectivity.

On the other hand, after supplying a source gas to a substrate having an insulating layer (Si ₃ N ₄ or SiO ₂ ) on the surface and exposing silicon, Cl ₂ gas is supplied as a selectivity promoting gas, and then the selectivity is selected. A method of performing selective epitaxial growth by supplying H ₂ gas as a promoting gas is also known (see, for example, Patent Document 2). Here, the purpose of supplying H ₂ gas is to deactivate the insulating layer surface and promote selectivity.
According to this, a decrease in selectivity can be prevented by supplying H ₂ gas to deactivate the insulating layer surface after supplying chlorine gas or fluorine gas. Therefore, it is possible to suppress the decrease in selectivity in Patent Document 1.
Japanese Patent Laid-Open No. 04-139819 JP 2003-86511 A

  However, the method described in Patent Document 2 has a problem in that the throughput of the semiconductor device manufacturing method is reduced due to an additional step of supplying hydrogen gas.

  An object of the present invention is to provide a method of manufacturing a semiconductor device that can improve the throughput while eliminating the above-described problems of the conventional technique and preventing the selectivity of selective epitaxial growth.

  The first aspect of the present invention is a first step of carrying a substrate having an insulating layer on a part of the surface and having an exposed silicon layer into a processing chamber, and a second step of supplying a source gas containing a silane-based gas into the processing chamber. A third step of supplying a chlorine-based gas or a fluorine-based gas into the processing chamber, a fourth step of supplying a hydrogen-based gas into the processing chamber, the second step, the third step, and the fourth step. And a fifth step in which a film is grown on the exposed silicon layer by sequentially repeating a plurality of times, and the pressure in the processing chamber in the fourth step is changed to the processing in the second step or the third step. A method of manufacturing a semiconductor device, wherein the pressure is larger than the indoor pressure.

  By supplying a source gas containing a silane-based gas in the second step, a film grows on the exposed silicon layer. At this time, silicon crystal nuclei are formed on the insulating layer. The silicon crystal nuclei are removed by reacting with the chlorine gas or fluorine gas by supplying chlorine gas or fluorine gas in the third step. At this time, chlorine or fluorine adheres to the silicon film and the insulating layer. Chlorine or fluorine adhering to the silicon film and the insulating layer is removed by reacting with the hydrogen gas by supplying a hydrogen gas in the fourth step. Therefore, it is possible to prevent the selectivity of the growth film on the silicon layer from being lowered. Further, the film thickness can be increased by supplying the silane gas once, and the throughput is improved.

  Further, since the pressure in the processing chamber in the fourth step for supplying the hydrogen-based gas is larger than the pressure in the processing chamber in the second step or the third step, the hydrogen-based gas and the chlorine-based gas or the fluorine-based gas The reaction rate can be increased. Therefore, even if a step of supplying hydrogen gas is newly added, a decrease in throughput can be suppressed.

A second invention is a method of manufacturing a semiconductor device according to the first invention, wherein the fifth step is performed at a growth temperature of 500 to 700 ° C.
In the fifth step, if the growth temperature is lower than 500 ° C., the throughput deteriorates and is not practical. Further, if the growth temperature is higher than 700 ° C., the incubation time is shortened and the selectivity is deteriorated. Therefore, 500-700 degreeC from which both a throughput and selectivity become favorable is good, Preferably 500-650 degreeC is good.

According to a third invention, in the first invention, the gas supplied in the second step is monosilane SiH ₄ , disilane Si ₂ H ₆ , monosilane SiH ₄ and monogermane GeH ₄ , disilane Si ₂ H ₆ and monogermane GeH. at least one gas selected from the group consisting of _4, the third gas supplied in step is at least one gas selected from chlorine Cl _2, hydrogen chloride HCl, the group consisting of fluorine F _2, wherein A method for manufacturing a semiconductor device is characterized in that the gas supplied in the fourth step is hydrogen H ₂ .

The gas containing the silane-based gas supplied in the second step is at least one gas selected from the group consisting of SiH ₄ , Si ₂ H ₆ , SiH ₄ and GeH ₄ , Si ₂ H ₆ and GeH _4. preferable. When monosilane and disilane are compared, disilane is more easily decomposed and grown at a lower temperature than monosilane. Therefore, disilane is preferable to meet the further demand for lowering the temperature. In manufacturing a MOSFET or the like, when an epitaxial film is formed on the source / drain, monosilane or disilane is used as a source gas. In manufacturing SiGe-HBT (Hetero Bipolar Transistor) or the like, when a SiGe film as a base layer is formed on a collector, monosilane or disilane and germane are used together as a source gas.

In addition, the chlorine-based gas or fluorine-based gas supplied in the third step is preferably at least one gas selected from the group consisting of chlorine (Cl ₂ ), hydrogen chloride (HCl), and fluorine (F ₂ ). .
When the gas supplied in the fourth step is H ₂ , H ₂ is most preferable because it alone does not contribute to film formation and does not cause film formation.

  According to a fourth aspect of the present invention, there is provided a processing container for processing a substrate, a support for supporting the substrate in the processing container, a source gas containing silane-based gas, chlorine gas or fluorine gas, and a hydrogen-based gas in the processing container. A supply means for supplying; a pressure control means for controlling the pressure in the processing container; a heating means for heating the substrate in the processing container; and a substrate having an insulating layer on a part of the surface and on which the silicon layer is exposed. When the film is grown on the exposed silicon layer, the supply means is controlled so as to sequentially supply a source gas containing silane-based gas, chlorine gas or fluorine gas, and hydrogen-based gas into the processing vessel, and the hydrogen The pressure control means is controlled so that the pressure in the processing chamber when supplying the system gas is larger than the pressure in the processing chamber when supplying the raw material gas or the chlorine gas or fluorine gas. A substrate processing apparatus and a control means. According to this, 1st invention can be implemented easily.

  According to the present invention, it is possible to improve the throughput while preventing the selectivity of selective epitaxial growth from being lowered.

Embodiments of the present invention will be described below with reference to the drawings.
First, with reference to FIG. 7, the outline of the processing furnace which comprises the two wafer processing apparatus for enforcing the manufacturing method of the semiconductor device of this invention is demonstrated.

  The reaction tube 203 as a processing vessel made of quartz, silicon carbide, or alumina has a flat space as a processing chamber in the horizontal direction, and accommodates a semiconductor wafer 200 as a substrate therein. Inside the reaction tube 203, a wafer support 217 as a substrate holding means for supporting the semiconductor wafer 200 is provided. A gas introduction flange 209 as a manifold is provided in the reaction tube 203 in an airtight manner. A transfer chamber (not shown) is connected via a gate valve 244 as a gate valve. A gas introduction line 232 as a supply pipe is connected to the gas introduction flange 209. An exhaust line 231 as an exhaust pipe is connected to the back flange 210. The exhaust line 231 is provided with pressure control means 242 for controlling the pressure in the reaction tube 203 to a predetermined pressure. In addition, a pressure turbo molecular pump 233 is connected to the exhaust line 231, and the inside of the reaction tube 203 is kept at a high vacuum by the turbo molecular pump. The gas introduction line 232 is provided with a flow rate control means 241 for controlling the flow rate of the gas introduced into the reaction tube 203.

  The processing furnace is a hot wall type. Therefore, an upper heater 207a and a lower heater 207b are provided above and below the reaction tube 203 as heating means, respectively, so that the inside of the reaction tube 203 is uniformly or has a predetermined temperature gradient. It comes to heat. The upper heater 207a and the lower heater 207b are connected to temperature control means 247 for controlling the respective heater temperatures. A heat insulating material 208 is provided as a heat insulating member so as to cover the upper heater 207a, the lower heater 207b, and the reaction tube 203. The temperature in the reaction tube 203, the flow rate of the gas supplied into the reaction tube 203, and the pressure in the reaction tube 203 are set to a predetermined temperature and flow rate by the temperature control means 247, flow rate control means 241, and pressure control means 242, respectively. , Controlled to be pressure. Further, the temperature control unit 247, the flow rate control unit 241, and the pressure control unit 242 are controlled by the main control unit 249.

  Next, a method of processing a wafer using the above-described single wafer hot wall type processing furnace will be described as one step of a semiconductor device manufacturing process. Here, an insulating layer such as a silicon nitride film or a silicon oxide film is partially formed on the surface, and a film is selectively formed on the exposed silicon layer of the semiconductor wafer from which the silicon layer is exposed.

With the temperature in the reaction tube 203 maintained at the processing temperature by the heaters 207a and 207b, the gate valve 244 is opened, and the semiconductor wafer 200 is loaded into the reaction tube 203 from the left in the drawing by a wafer transfer robot (not shown). The wafer is placed on the wafer support 217 (wafer load).
Here, two wafers 200 are placed on the wafer support 217, and the two wafers 200 are processed simultaneously. Note that two wafers 200 are simultaneously transferred into the reaction tube 203 in order to equalize the thermal history of the two wafers 200 to be processed simultaneously. At the same time when the wafer 200 is carried into the reaction tube 203, the temperature rise to the processing temperature of the wafer 200 is started (preheating).

  After the wafer transfer robot moves backward and the gate valve 244 is closed, the temperature in the reaction tube 203 is controlled by the temperature control means 247 so that the wafer temperature becomes the processing temperature (temperature stabilization). When the temperature of the wafer 200 in the reaction tube 203 is stabilized, the reaction tube 203 is exhausted from the exhaust line 231 while being introduced from the gas introduction line 232, and the reaction tube 203 has an inert gas atmosphere. It is said.

  After the temperature of the wafer 200 in the reaction tube 203 is stabilized at the processing temperature, a gas for wafer processing whose flow rate is controlled by the flow rate control means 241 is introduced into the reaction tube 203 from the gas introduction line 232, and the exhaust line 231. By being further evacuated, the wafer 200 is processed.

The wafer processing gas introduction process described above includes the following four steps. That is, a source gas supply step for supplying a source gas containing a silane-based gas into the reaction tube 203, a chlorine-based gas supply step for supplying a chlorine-based gas or a fluorine-based gas into the reaction tube 203, A film growth process for growing a film on the exposed silicon layer by repeating a hydrogen gas supply step, a source gas supply step, a chlorine gas supply step and a hydrogen gas supply step in order several times in order. Steps. At this time, the above-described raw material gas, chlorine-based gas, and the like, and hydrogen-based gas are supplied to the reaction tube 203 by controlling the flow rate by the flow rate control unit 241.
Further, the pressure in the reaction tube 203 in the hydrogen-based gas supply step is set to be larger than the pressure in the reaction tube 203 in the source gas supply step or the chlorine-based gas supply step. This pressure control is performed by the pressure control means 242.

  When the processing of the wafer 200 is completed, an inert gas whose flow rate is controlled by the flow rate control unit 241 is introduced into the reaction tube 203 from the gas introduction line 232 in order to remove the residual gas in the reaction tube 203. The gas is exhausted from the exhaust line 231 and the inside of the reaction tube 203 is purged.

  After purging the reaction tube 203, the gate valve 244 is opened, and the wafer 200 is unloaded from the reaction tube 203 to the transfer chamber by the wafer transfer robot (wafer unload).

  The temperature control in the reaction tube 203 by the temperature control means 247 described above, the gas flow rate control during wafer processing into the reaction tube 203 by the pressure control means 242, the inert gas gas flow control before or after wafer processing, The pressure control in the reaction tube 203 by the pressure control means 242 is performed by the main control unit 249 controlling each control means.

  By supplying a source gas containing a silane-based gas in the source gas supply step, a film grows on the exposed silicon layer. At this time, silicon crystal nuclei are formed on the insulating layer. The silicon crystal nucleus is removed by reacting with the chlorine-based gas or the fluorine-based gas by supplying the chlorine-based gas or the fluorine-based gas in the chlorine-based gas supply step. At this time, chlorine or fluorine adheres to the silicon film and the insulating layer. Chlorine or fluorine adhering to the silicon film and the insulating layer is removed by reacting with the hydrogen-based gas by supplying the hydrogen-based gas in the hydrogen-based gas supply step. Therefore, it is possible to prevent the selectivity of the growth film on the silicon layer from being lowered.

  Moreover, since the pressure in the reaction tube 203 in the hydrogen gas supply step for supplying the hydrogen gas is larger than the pressure in the reaction tube 203 in the raw material gas supply step or the chlorine gas supply step, the hydrogen gas And the reaction rate between the chlorine-based gas and the fluorine-based gas can be increased. Therefore, even if a step of supplying hydrogen gas is newly added, a decrease in throughput can be suppressed.

As described above, in the embodiment, in a silicon wafer having a silicon nitride film or a silicon oxide film on at least a part of the surface and exposing the silicon surface, the silicon wafer is inserted into the reaction tube, and the silane system is inserted into the reaction tube. These gases, chlorine gas, fluorine gas, and hydrogen gas are sequentially introduced, and these are repeated to perform selective epitaxial growth. Thereby, chlorine or fluorine adhering to the silicon surface after supplying chlorine or fluorine gas can be removed with hydrogen gas. For this reason, in the embodiment, as compared with the case where silane-based gas and chlorine gas or fluorine gas are alternately introduced, chlorine gas or fluorine gas does not remain at the time of supplying silane-based gas, so one-time silane-based gas supply Thus, the film thickness can be increased and the throughput can be improved. In addition, chlorine or fluorine does not affect the incubation time on the silicon nitride film or silicon oxide film, so chlorine or fluorine deposited on the silicon layer may cause the selectivity to deteriorate. For example, since chlorine or fluorine adhering to the silicon layer is removed, the selectivity can be improved at the same time.
Therefore, if the embodiment is applied to a MOSFET, it is possible to realize a reduction in source / drain leakage current and a reduction in resistance, and to achieve both improvement of semiconductor device characteristics and miniaturization.

  In the embodiment, the case where a single-wafer hot wall type apparatus is used has been described. However, the present invention is not limited to this, and the present invention is not limited to this, and may be applied to a general substrate processing apparatus, for example, a single-wafer cold wall apparatus or a batch type vertical apparatus. can do. Moreover, although the said embodiment demonstrated the process after the chlorine-type gas or fluorine-type gas at the time of selective epitaxial growth, this invention is not limited to this. Also applicable to self-cleaning of substrate processing chambers, such as removing residual cleaning gas components when removing silicon or silicon nitride film deposited in the processing chamber using chlorine trifluoride or nitrogen trifluoride. can do. The gas for removal can be applied to a gas containing hydrogen, for example, a gas combined with hydrogen such as monosilane or ammonia. The removal effect is not limited to those bonded to hydrogen, but includes those due to bonding to silicon or nitrogen. Further, the deposited film is not limited to the silicon film, and can be applied to all films deposited using a chemical reaction on the substrate surface, such as a silicon nitride film.

A silicon epitaxial film was formed on the exposed polysilicon layer using a single wafer hot wall type processing furnace having the configuration of FIG.
An example of the process sequence at this time is shown in FIG. The silicon wafer 200 having the insulating layer 13 on a part of the surface and exposing the polysilicon layer 11 is loaded into the reaction tube 203 by a wafer transfer robot (not shown) (step 101).
When the silicon wafer 200 is loaded into the reaction tube 203, the upper heater 207a and the lower heater 207b are controlled by the temperature control means 247 controlled under the main control unit 249, and preheated to the processing temperature of the wafer 200 simultaneously with the loading. (Step 102).

The main controller 249 controls the flow rate control means 241 to supply a predetermined flow rate of disilane gas Si ₂ H ₆ into the reaction tube 203 (step 103).
After supplying the disilane gas, the main control unit 249 controls the flow rate control means 241 to supply a predetermined flow rate of chlorine gas Cl ₂ into the reaction tube 203 (step 104).
After supplying the chlorine gas, the main control unit 249 controls the flow rate control means 241 to supply a predetermined flow rate of hydrogen gas H ₂ into the reaction tube 203 (step 105).

Step 103, step 104, and step 105 are sequentially repeated a plurality of times by main controller 249 to grow epitaxial film 12 on exposed polysilicon layer 11. Here, the pressure in the reaction tube 203 in step 105 is made larger than the pressure in the reaction tube 203 in step 103 or 104 by controlling the pressure control means 242 with the main control unit 249.
FIG. 2 shows a timing chart of introduction of various gases and pressure control described above.

  After the epitaxial film 12 is grown on the polysilicon layer 11, the wafer is unloaded from the reaction tube 203 by a wafer transfer robot (not shown) (step 106).

Here, the phenomenon that occurs in the Si ₂ H ₆ supply step 103, the Cl ₂ or F ₂ supply step 104, and the H ₂ supply step 105 described above will be described with reference to FIG.
(A) Si ₂ H ₆ Supply Step As shown in FIG. 3A, an epitaxial film 12 grows on the exposed surface of the silicon layer 11. Although no film is formed on the insulating layer 13, Si crystal nuclei 14 are formed.

(B) Cl ₂ or F ₂ supply step As shown in FIG. 3B, the Si crystal nuclei 14 on the insulating layer 13 react with Cl ₂ or F ₂ 15 and are removed. The reaction formula is as follows.
2Cl ₂ + Si → SiCl ₄
2F ₂ + Si → SiF ₄
At this time, Cl or F adheres to the epitaxial film 12 and the insulating layer 13.

(C) H ₂ supply step As shown in FIG. 3C, Cl or F adhering to the epitaxial film 12 and the insulating layer 13 reacts with H ₂ and is removed. The reaction formula is as follows.
H ₂ + 2Cl → 2HCl
H ₂ + 2F → 2HF

The above cycle of disilane gas supply → chlorine gas supply → hydrogen gas supply is performed n times ((Si ₂ H ₆ supply → Cl ₂ supply → H ₂ supply) × n). Thereby, the silicon epitaxial film thickness formed on the polysilicon layer 11 was evaluated.
FIG. 4 shows the dependence of the epitaxial film thickness on the polysilicon layer and the hydrogen gas supply time after chlorine gas supply. Hydrogen gas is supplied after chlorine gas is supplied. The vertical axis represents the silicon epitaxial film thickness, and the horizontal axis represents the hydrogen supply time after chlorine gas supply.

The conditions for obtaining the characteristics of FIG. 4 are a growth temperature of 625 ° C., a disilane gas flow rate of 20 sccm, and a chlorine gas flow rate of 10 sccm. The pressure when supplying disilane and chlorine gas was 0.05 Pa. The hydrogen gas flow rate was 500 sccm or 1000 sccm. The pressure at the time of hydrogen gas supply was 1.1 Pa when the hydrogen gas flow rate was 500 sccm, and 8.7 Pa when the hydrogen gas flow rate was 1000 sccm. The above cycle is n = 20 times.
As shown in the figure, when hydrogen gas is not supplied after supplying chlorine gas (refer to H ₂ gas supply time at 0 sec), the silicon epitaxial film thickness is thin, but if hydrogen gas is introduced after introducing chlorine gas, It can be seen that a thicker silicon epitaxial film can be obtained by increasing the epitaxial film thickness and increasing the hydrogen gas flow rate and the supply time.

Even if evacuation (1 × 10 ⁻⁵ Pa, 240 sec) was performed after supplying chlorine gas, the silicon epitaxial film thickness was 13.0 nm, and chlorination could not sufficiently remove chlorine Cl. Further, even when N ₂ = ₂ slm and a purge of 120 sec were performed, only a film thickness equivalent to that of evacuation was obtained. It is considered that chlorine adhering to the silicon surface inhibits epitaxial growth. Therefore, in Example 1, by supplying hydrogen gas, Cl which is a silicon epitaxial growth inhibiting factor is removed in the form of H ₂ + 2Cl → 2HCl.

As described above, in silicon epitaxial growth using Si ₂ H ₆ which is a silane-based gas, chlorine Cl ₂ or fluorine F ₂ deposited on the silicon layer is effectively used by using H ₂ gas which is not formed alone. Can be removed. Therefore, throughput and selectivity can be improved.

In Example 1, preferable processing conditions are as follows.
(A) Temperature is 500-700 degreeC, Preferably it is 500-650 degreeC.
If the temperature is lower than 500 ° C., the throughput deteriorates and is not practical.
If the temperature is higher than 700 ° C., the incubation time is shortened and the selectivity is deteriorated.

(B) The pressure is different between when Si ₂ H ₆ and Cl _{2 are} supplied and when H _{2 is} supplied. When supplying Si ₂ H ₆ and Cl ₂ , the pressure is set to 1 × 10 ^{−5 to} 1 Pa. When H _{2 is} supplied, the pressure is set to 0.1 to 1000 Pa, preferably 0.1 to 100 Pa.
If the pressure at the time of supplying H ₂ is lower than 0.1 Pa, the reaction rate between H ₂ , Cl, and F becomes slow and the throughput decreases. Considering safety, it is preferably set to 1000 Pa or less.
In Example 1, the pressure at the time of supplying H ₂ is controlled to be higher than the pressure at the time of supplying Si ₂ H ₆ , Cl ₂ or F ₂ . This is to increase the reaction rate between H ₂ and Cl or F when H _{2 is} supplied, and to remove Cl or F adhering to the silicon surface quickly.
In particular, in recent years, there has been a demand for lowering the temperature, but with the lowering of temperature, the incubation time on the insulating layer becomes longer and the selectivity is improved, but the deposition rate is lowered. Even in that case, the removal rate of Cl or F can be increased by increasing the atmosphere during the supply of H ₂ , and as a result, the throughput can be improved. In order to increase the atmosphere during the supply of H ₂ , for example, by supplying a large flow rate of H ₂ .

(C) The gas is preferably SiH ₄ or Si ₂ H ₆ when a MOSFET is manufactured as a source gas containing a silane-based gas. In addition, SiH ₄ + GeH ₄ , Si ₂ H ₆ + GeH ₄ is preferable when SiGe-HBT is manufactured by including a germanium-based gas in a source gas including a silane-based gas. As the chlorine-based gas and fluorine-based gas, Cl ₂ , HCl, and F ₂ are preferable. As the hydrogen-based gas, H ₂ that does not contribute to film formation alone and does not cause film formation is most preferable. For example, a gas flow rate of 5 to 300 sccm, a chlorine gas flow rate of 1 to 500 sccm, and a hydrogen gas flow rate of 50 to 50000 sccm.

In the first embodiment, the H ₂ supply pressure is set higher than the Si ₂ H ₆ , Cl ₂ or F ₂ supply pressure. In this respect, it is possible not to increase the pressure when supplying H ₂ , but in this case, the reaction rate of H ₂ and Cl is decreased, and it is considered that the throughput decreases when viewed in total. Absent.

In the first embodiment, H _{2 is} supplied as (Si ₂ H ₆ supply → Cl ₂ supply → H ₂ supply) × n. In this respect, it is conceivable that H ₂ is not supplied as (Si ₂ H ₆ supply → Cl ₂ supply) × n. In this case, even if Si ₂ H ₆ is supplied, Since there is a latent period in which the epitaxial growth does not start, there is a disadvantage that the throughput is lowered, which is not preferable.

In Example 1, Si ₂ H ₆ and Cl ₂ are sequentially supplied. However, the present invention is not limited to this. For example, Si ₂ H ₆ and Cl ₂ may be supplied simultaneously. As shown in FIG. 5, (Si ₂ H ₆ + Cl ₂ supply → H ₂ supply) × n. However, since Cl ₂ may interfere with the decomposition of Si ₂ H ₆ and the selectivity may be easily broken, Cl ₂ and Si ₂ H ₆ are supplied separately as in the first embodiment. Is preferred.

In the first embodiment, the case of selective epitaxial growth on the silicon layer has been described. However, it is also possible to grow a polycrystalline silicon film on the insulating layer simultaneously with the epitaxial growth on the silicon layer. In this case, the insulating layer includes a silicon nitride film and a silicon oxide film.
Specifically, by increasing the supply time of the Si ₂ H ₆ gas or increasing the processing temperature, the epitaxial film 12 is grown on the silicon layer 11 as shown in FIG. A polysilicon film 16 can be grown on the layer 13.

It is a flowchart which shows the process sequence example which processes the board | substrate which has an insulating layer in a part of surface by Example 1, and the silicon layer exposed. FIG. 6 is a timing chart of various gas introduction and pressure control according to the first embodiment. It is explanatory drawing of the phenomenon which arises in each step by Example 1. FIG. It is a figure which shows the hydrogen gas supply time dependence of the epitaxial film thickness by Example 1. FIG. FIG. 6 is a timing chart of various gas introduction and pressure control according to the second embodiment. It is explanatory drawing which grows simultaneously an epitaxial film on the silicon layer by Example 3, and a polysilicon film on an insulating layer. It is a schematic explanatory drawing of the processing furnace of the 2 sheet | seat apparatus as a substrate processing apparatus of embodiment.

Explanation of symbols

11 Exposed silicon layer 12 Epitaxial film 13 Insulating layer 200 Wafer

Claims (3)

A first step of carrying a substrate having an insulating layer on a part of the surface and having an exposed silicon layer into a processing chamber;
A second step of supplying a source gas containing a silane-based gas into the processing chamber;
A third step of supplying chlorine-based gas or fluorine-based gas into the processing chamber;
A fourth step of supplying a hydrogen-based gas into the processing chamber;
A fifth step of growing a film on the exposed silicon layer by repeating the second step, the third step, and the fourth step a plurality of times in order,
A method for manufacturing a semiconductor device, wherein the pressure in the processing chamber in the fourth step is made larger than the pressure in the processing chamber in the second step or the third step.   2. The method of manufacturing a semiconductor device according to claim 1, wherein the fifth step is performed at a growth temperature of 500 to 700 ° C. 3. The gas supplied in the second step is at least one gas selected from the group consisting of SiH ₄ , Si ₂ H ₆ , SiH ₄ and GeH ₄ , Si ₂ H ₆ and GeH ₄ , and supplied in the third step. _2. The semiconductor device according to claim 1, wherein the gas to be supplied is at least one gas selected from the group consisting of Cl ₂ , HCl, and F ₂ , and the gas supplied in the fourth step is H _2. Manufacturing method.

Images