CN103137415B - Semiconductor-fabricating device and semiconductor making method - Google Patents

Abstract

The invention provides a semiconductor manufacturing device and a semiconductor manufacturing method, which can improve the etching selectivity of a nitride film when performing an etching process. In the semiconductor manufacturing apparatus of the present invention, plasma is generated from difluoromethane CH ₂ F ₂ , nitrogen N ₂ , and oxygen O ₂ gases outside the process chamber, and the generated plasma is supplied into the process chamber. According to the present invention, the ratio of the etching selectivity of the silicon nitride film to the silicon oxide film and the etching selectivity of the silicon nitride film to the polysilicon film can be adjusted by adjusting the supply amount of oxygen gas and the temperature of the chuck without changing the source gas. The relative size is adjusted to the opposite.

Description

Semiconductor manufacturing device and semiconductor manufacturing method

technical field

The present invention relates to a semiconductor manufacturing device and a semiconductor manufacturing method, and more specifically, to a semiconductor manufacturing device and a semiconductor manufacturing method for etching a substrate.

Background technique

In order to manufacture semiconductor elements, various processes such as vapor deposition, photography, etching, ashing, and cleaning are required. Among them, the etching process is a process for removing a thin film in a desired region of a thin film formed on a semiconductor substrate such as a wafer, and recently, a method of etching a thin film by plasma is often used. One of the important considerations in such an etching process is the etching selectivity. The etching selectivity indicates the degree to which only the thin film to be etched is etched without etching other thin films.

In a thin film, etching of a silicon nitride film (Silicon Nitride, SiN) is generally performed as follows. First, a substrate is placed on a chuck in a process chamber, source gases are supplied into the process chamber, and plasma is generated in the process chamber from these gases. The plasma reacts chemically with the thin film to remove the thin film on the substrate. As a source gas for etching a silicon nitride film, carbon tetrafluoride (CF ₄ , tetrafluoromethane), trifluoromethane (CHF ₃ , trifluoromethane), and oxygen O ₂ are often used. However, in the case of etching the silicon nitride film using the above-mentioned device structure and the above-mentioned gas, even if the process conditions such as the temperature of the chuck and the pressure in the process chamber are changed, the silicon nitride film is relatively weak compared with the silicon oxide film or polysilicon film. The etch selectivity of the membrane is also very low, around 30:1 to 50:1 or so.

In addition, generally during the etching process, the relative magnitudes of the etching selectivity ratio of the silicon nitride film to the silicon oxide film and the etching selectivity ratio of the silicon nitride film to the polysilicon film remain unchanged and do not change greatly. However, when the state of the thin film formed on the substrate changes as the etching process progresses, the etching progresses inefficiently when the process is performed by the above etching method.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2004-172584

Contents of the invention

An object of the present invention is to provide a semiconductor manufacturing device and a semiconductor manufacturing method capable of increasing the etching selectivity of a nitride film relative to other thin films when an etching process is performed on a substrate.

In addition, an object of the present invention is to provide a method capable of adjusting the relative size of the etching selectivity ratio of the silicon nitride film to the silicon oxide film and the etching selectivity ratio of the silicon nitride film to the polysilicon film during the etching process. Semiconductor manufacturing apparatus and semiconductor manufacturing method.

The problems to be solved by the present invention are not limited thereto, and those skilled in the art will clearly understand other problems not mentioned from the following description.

The present invention provides a semiconductor manufacturing method for etching a nitride film formed on a substrate. According to one embodiment of the present invention, a substrate is placed on a susceptor formed in a process chamber, plasma is generated from a first source gas outside the process chamber, the plasma is supplied to the process chamber, and the first 1. The source gas includes difluoromethane CH ₂ F ₂ , nitrogen N ₂ , and oxygen O ₂ . During the process, the supply amount of the oxygen gas or the temperature of the process chamber is changed.

According to the semiconductor manufacturing method of the present invention, any one of the supply amount of the oxygen gas and the temperature of the process chamber can be increased while the other can be decreased.

According to the semiconductor manufacturing method of the present invention, the temperature adjustment of the process chamber includes temperature adjustment of the susceptor.

According to the above-mentioned semiconductor manufacturing method of the present invention, the supply amount of the above-mentioned oxygen is changed between the range of 100 to 2000 SCCM and the range of 2000 to 2500 SCCM, and the temperature of the above-mentioned process chamber is in the range of 40°C to 70°C and 10°C to 40°C Change between ranges.

When changing the supply amount of the oxygen gas or the temperature of the process chamber, the supply amount of the difluoromethane can be kept constant.

When changing the supply amount of the oxygen gas or the temperature of the process chamber, the supply amount of the nitrogen gas may be changed.

According to the above-mentioned semiconductor manufacturing method of the present invention, when the above-mentioned process is carried out, the temperature of the above-mentioned susceptor is 0 to 70° C., the supply amount of the above-mentioned difluoromethane CH ₂ F ₂ gas is 10 to 500 SCCM, and the supply of the above-mentioned nitrogen N ₂ gas is The amount is 100 to 2500SCCM, and the supply amount of the above-mentioned oxygen _O2 gas is 100 to 2500SCCM. In addition, the pressure in the process chamber is 300 to 1000 mTorr. In addition, when the process is in progress, the power supplied to generate the plasma is 1000 to 3000W.

According to the semiconductor manufacturing method of the present invention, when the supply amount of the oxygen gas or the temperature of the process chamber is changed, the magnitude of the electric power can also be changed.

In addition, a second source gas may be supplied to a passage for supplying the plasma to the process chamber, and the second source gas may contain nitrogen trifluoride NF ₃ . When the etching process is performed, the supply amount of the above-mentioned nitrogen trifluoride is greater than 0 and less than or equal to 1000 SCCM.

In addition, the present invention provides a semiconductor manufacturing method of etching a silicon nitride film on a substrate on which a polysilicon film, a silicon oxide film, and a silicon nitride film are formed. According to the semiconductor manufacturing method described above, plasma is generated from a first source gas containing difluoromethane CH ₂ F ₂ , nitrogen N ₂ , and oxygen O ₂ in a state where the substrate is placed on a susceptor in a process chamber, Etching the above-mentioned silicon nitride film, by changing the supply amount of the above-mentioned oxygen gas or the temperature of the above-mentioned process chamber, the etching selectivity ratio of the above-mentioned silicon nitride film relative to the above-mentioned silicon oxide film and the ratio of the above-mentioned silicon nitride film relative to the above-mentioned polysilicon film are adjusted. Relative size of etch selectivity.

According to the semiconductor manufacturing method of the present invention, the plasma may be supplied to the process chamber after the plasma is generated outside the process chamber.

According to the semiconductor manufacturing method of the present invention, any one of the supply amount of the oxygen gas and the temperature of the process chamber can be increased while the other can be decreased.

According to the above-mentioned semiconductor manufacturing method of the present invention, the temperature adjustment of the above-mentioned process chamber includes adjusting the temperature of the above-mentioned susceptor, the supply amount of the above-mentioned oxygen is changed between the range of 100 to 2000 SCCM and the range of 2000 to 2500 SCCM, and the temperature of the above-mentioned susceptor is between It varies between the range of 40°C to 70°C and the range of 10°C to 40°C.

According to the semiconductor manufacturing method of the present invention, when changing the supply amount of the oxygen gas or the temperature of the process chamber, the supply amount of the difluoromethane and the nitrogen gas may be changed together. In addition, when changing the supply amount of the oxygen gas or the temperature of the process chamber, the pressure in the process chamber is kept constant.

According to the semiconductor manufacturing method of the present invention, when changing the supply amount of the oxygen gas or the temperature of the process chamber, it is also possible to change the magnitude of electric power supplied to generate plasma.

According to the semiconductor manufacturing method of the present invention, the supply amount of the difluoromethane CH ₂ F ₂ is 10 to 500 SCCM, the supply amount of the nitrogen gas is 100 to 2500 SCCM, and the supply amount of the oxygen gas is 100 to 2500 SCCM. In addition, the temperature of the susceptor on which the substrate is placed is 0 to 70° C., and the pressure in the process chamber is 300 to 1000 mTorr.

In addition, the present invention provides a semiconductor manufacturing device. The above-mentioned semiconductor manufacturing apparatus includes: a process unit that performs an etching process; a plasma supply unit formed outside the above-mentioned process unit for supplying plasma to the above-mentioned process unit; and a controller that controls The aforementioned process unit and the aforementioned plasma supply unit. The process unit includes: a process chamber; a base supporting the substrate, the base is located in the process chamber and has a heating part. The plasma supply unit includes: a plasma chamber having a discharge space inside, and the plasma chamber is formed outside the process unit; a first source gas supply part that supplies a first source gas to the discharge space. a gas; a power applying unit that supplies power to generate plasma from the first source gas in the discharge space; and an inflow conduit configured to supply the plasma generated in the discharge space to the access to the process chamber. The first source gas includes difluoromethane CH ₂ F ₂ , nitrogen N ₂ and oxygen O ₂ . The controller changes the supply amount of the oxygen gas or the temperature of the process chamber during the progress of the process.

According to the semiconductor manufacturing device of the present invention, the plasma chamber is combined with the process chamber at the upper part of the process chamber, and the process unit further includes a baffle located at the upper part of the base, and the baffle is formed with a plurality of through hole.

According to the semiconductor manufacturing apparatus of the present invention, the plasma supply unit may further include a second source gas supply unit that supplies a second source gas to a passage through which the plasma generated in the discharge space flows to the process chamber. , the second source gas contains nitrogen trifluoride NF ₃ .

Invention effect

According to the embodiments of the present invention, it is possible to increase the etching selectivity of the nitride film when an etching process is performed on the substrate.

In addition, according to an embodiment of the present invention, when an etching process is performed on a substrate using plasma, it is possible to greatly increase the etching selectivity of a silicon nitride film with respect to a silicon oxide film or a polysilicon film.

In addition, according to the embodiment of the present invention, by changing the process conditions during the etching process, it is possible to adjust the relative size of the etching selectivity ratio of the silicon nitride film to the silicon oxide film and the etching selectivity ratio of the silicon nitride film to the polysilicon film. .

In addition, according to the embodiment of the present invention, in the case of using the same source gas, the amount of oxygen gas used and/or the temperature of the process chamber can also be changed to make the etching selectivity of the silicon nitride film relative to the silicon oxide film The ratio is adjusted inversely to the relative magnitude of the etching selectivity ratio of the silicon nitride film to the polysilicon film.

Description of drawings

FIG. 1 is a diagram schematically showing a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is an experimental example showing an etching selectivity ratio of a silicon nitride film to a silicon oxide film and a polysilicon film when an etching process is performed under a first process condition using the apparatus of FIG. 1 .

3 is an experimental example showing an etching selectivity ratio of a silicon nitride film to a silicon oxide film and a polysilicon film when an etching process is performed under a second process condition using the apparatus of FIG. 1 .

FIG. 4 is an experimental example showing an etching selectivity ratio of a silicon nitride film to a silicon oxide film and a polysilicon film when an etching process is performed using an apparatus configuration different from that of FIG. 1 .

FIG. 5 is a flowchart of a method of performing an etching process according to an embodiment of the present invention.

Description of symbols in the figure

100···process chamber

200···Exhaust unit

300···Plasma supply parts

310···plasma chamber

320···Source gas supply unit

330···Electric power application department

340···inflow conduit

detailed description

Hereinafter, a semiconductor manufacturing apparatus and a semiconductor manufacturing method according to an embodiment of the present invention will be described in detail with reference to the drawings. In the description of the present invention, when it is judged that a specific description of related known configurations or functions may obscure the gist of the present invention, the detailed description will be omitted.

In this embodiment, the substrate is a semiconductor wafer. However, it is not limited thereto, and the substrate may be other types of substrates such as glass substrates.

FIG. 1 is a diagram showing a semiconductor manufacturing apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , a semiconductor manufacturing apparatus 1 etches a thin film on a substrate W using plasma. A plurality of films including a polysilicon film, a silicon oxide film, and a silicon nitride film are formed on a substrate, and the thin film to be etched is a nitride film. As an example, the nitride film is a silicon nitride film (Silicon nitride).

The semiconductor manufacturing apparatus 1 has a processing unit (processing unit, 100 ), an exhausting unit (exhausting unit, 200 ), a plasma supplying unit (plasma supplying unit, 300 ), and a controller (not shown). The process unit 100 provides a space for placing a substrate and performing an etching process. The exhaust unit 200 exhausts the process gas remaining inside the process chamber 100 and the reaction products generated during the substrate processing to the outside to maintain the pressure in the process chamber 100 at a set pressure. The plasma supply unit 300 generates plasma (plasma) from a process gas outside the process unit 100 and supplies the plasma to the process unit 100 . The controller controls the process unit 100 and the plasma supply unit 300 .

The process unit 100 has a process chamber 110 , a substrate supporting part 120 and a baffle 130 . The inside of the process chamber 110 forms a processing space 111 in which a substrate processing process is performed. The upper wall of the process chamber 110 is opened, and an opening (not shown) may be formed in a side wall. The substrate enters and exits the process chamber 110 through the opening. The opening is opened and closed by an opening and closing member such as a door (not shown). Exhaust holes 112 are formed on the bottom surface of the process chamber 110 . The exhaust hole 112 is connected to the exhaust unit 200 and provides a passage for exhausting the remaining gas and reaction products inside the process chamber 110 to the outside.

The substrate supporting part 120 supports the substrate W. As shown in FIG. The substrate supporting part 120 includes a base 121 and a supporting shaft 122 . The susceptor 121 is located in the processing space 111 and is formed in a disk shape. The base 121 is supported by a support shaft 122 . The substrate W is provided on the susceptor 121 . Electrodes (not shown) are formed inside the susceptor 121 . The electrodes are connected to an external power source, and static electricity is generated by the applied power. The generated static electricity fixes the substrate W on the susceptor 121 . A heating member 125 is formed inside the susceptor 121 . As an example, the heating element 125 may be a heating coil. In addition, a cooling member 126 is formed inside the base 121 . The cooling unit 126 is constituted by a cooling line through which cooling water flows. The heating unit 125 heats the substrate W to a set temperature. The cooling member 126 forcibly cools the substrate W.

In addition, a chamber wall heater 118 is formed outside the process chamber 110 . The chamber wall heater 118 is formed in a coil shape. A chamber wall heater 118 is optionally formed within an outer wall of the process chamber 110 . The baffle 130 is located on the upper portion of the base 121 . The baffle 130 forms a through hole 131 . The through holes 131 are through holes formed from the top to the bottom of the baffle 130 , and are uniformly formed in each area of the baffle 130 .

Referring again to FIG. 1 , the plasma supply unit 300 is located at an upper portion of the process chamber 110 . The plasma supply unit 300 discharges the source gas to generate plasma, and supplies the generated plasma to the processing space 111 . The plasma supply unit 300 includes a plasma chamber 310 , a first source gas supply unit 320 , a second source gas supply unit 322 , a power application unit 330 , and an inflow conduit 340 .

The plasma chamber 310 is located outside the process chamber 110 . As an example, the plasma chamber 310 is located at an upper portion of the process chamber 110 and is combined with the process chamber 110 . Inside the plasma chamber 310 is formed a discharge space 311 with an open top and bottom. The upper end of the plasma chamber 310 is sealed by a gas supply port 315 . The gas supply end 315 is connected to the first source gas supply part 320 . The first source gas is supplied to the discharge space 311 through the gas supply port 315 . The first source gas contains difluoromethane (CH ₂ F ₂ , Difluoromethane), nitrogen N ₂ , and oxygen O ₂ . Optionally, the first source gas may also contain other types of gases such as carbon tetrafluoride (CF ₄ , Tetrafluoromethane).

The power applying unit 330 applies high-frequency power to the discharge space 311 . The power applying unit 330 includes an antenna 331 and a power source 332 .

The antenna 331 is an inductively coupled plasma (ICP) antenna formed in a coil shape. The antenna 331 is wound multiple turns on the plasma chamber 310 outside the plasma chamber 310 . The antenna 331 is wound around the plasma chamber 310 in a region corresponding to the discharge space 311 . One end of the antenna 331 is connected to the power source 332, and the other end is grounded.

The power supply 332 supplies high-frequency current to the antenna 331 . The high-frequency power supplied to the antenna 331 is applied to the discharge space 311 . The high-frequency current forms an induced electric field in the discharge space 311, and the first source gas in the discharge space 311 obtains energy required for ionization from the induced electric field, and transforms into a plasma state.

The structure of the power application unit 330 is not limited to the above example, and various structures in which plasma is generated from the first source gas can be used.

The inflow conduit 340 is located between the plasma chamber 310 and the process chamber 110 . The inflow conduit 340 seals the open upper surface of the process chamber 110 , and the lower end is combined with the baffle plate 130 . The inside of the inflow duct 340 forms an inflow space 341 . The inflow space 341 connects the discharge space 311 and the processing space 111 , and forms a path for supplying plasma generated in the discharge space 311 to the processing space 111 .

The inflow space 341 may include an inflow port 341a and a diffusion space 341b. The inflow port 341a is located below the discharge space 311 and connected to the discharge space 311 . Plasma generated in the discharge space 311 flows in through the inflow port 341a. The diffusion space 341b is located under the inlet 341a, and connects the inlet 341a and the processing space 111 . As the diffusion space 341b goes downward, the cross-sectional area gradually becomes wider. The diffusion space 341b has an inverted funnel shape. The plasma supplied from the inflow port 341a is diffused while passing through the diffusion space 341b.

A second source gas supply unit 322 may be connected to a passage for supplying plasma generated in the discharge space 311 to the process chamber 110 . For example, the second source gas supply unit 322 supplies the second source gas to a passage through which plasma flows between the position where the lower end of the antenna 331 is formed and the position where the upper end of the diffusion space 341b is formed. As an example, the second source gas contains nitrogen trifluoride NF ₃ (Nitrogen trifluoride). Alternatively, the etching process may be performed using only the first source gas without supplying the second source gas.

Next, a method of etching the substrate W using the semiconductor manufacturing apparatus of FIG. 1 will be described. The semiconductor manufacturing apparatus 1 shown in FIG. 1 is a type of remote plasma apparatus that generates plasma outside the processing unit 100 and supplies the plasma to the process chamber 110 in a downstream manner. According to this embodiment, difluoromethane CH ₂ F ₂ , nitrogen trifluoride NF ₃ , nitrogen N ₂ , and oxygen O ₂ are used as the source gas. Difluoromethane CH ₂ F ₂ , nitrogen N ₂ , and oxygen O ₂ are directly supplied to the discharge space 311 , and nitrogen trifluoride NF ₃ is supplied to a passage for supplying plasma generated in the discharge space 311 to the process chamber 110 . In addition, carbon tetrafluoride CF ₄ may be used as the first source gas.

During the etching process, process conditions are provided as follows. At this time, the selectivity ratio of the silicon nitride film to the silicon oxide film is realized at about 100:1 to 3000:1, and the selectivity ratio of the silicon nitride film to the polysilicon film is realized at a high selectivity ratio of about 100:1 to 1000:1. accomplish.

(process conditions)

Base temperature: 0 to 70°C

Supply amount of difluoromethane CH ₂ F ₂ gas: 10 to 500 SCCM

Supply amount of nitrogen trifluoride NF ₃ gas: 0 to 1000SCCM

Supply amount of nitrogen _N2 gas: 100 to 2500SCCM

Supply amount of oxygen _O2 gas: 100 to 2500SCCM

Power: 1000～3000W

Pressure in process chamber: 300 to 1000mTorr

When the etching process is performed, in the case of using difluoromethane _{CH 2 F 2 together with nitrogen N 2 and} oxygen _O , through the mechanism of difluoromethane CH ₂ F ₂ forming C _x H _y polymer film on poly silicon film (poly silicon) and silicon oxide film (silicon oxide) at the same time, and using oxygen O ₂ and nitrogen N ₂ to remove the above polymer The mechanism of the film can greatly increase the etching selectivity of the silicon nitride film relative to the polysilicon film and the silicon oxide film.

In addition, although the type of source gas is not changed in the process conditions during the etching process, the etching selectivity ratio of the silicon nitride film to the silicon oxide film and the etching selectivity ratio of the silicon nitride film to the polysilicon film can also be changed. relative size.

Etching Selectivity Under the following first process condition, the etching selectivity of the silicon nitride film to the silicon oxide film is higher than the etching selectivity of the silicon nitride film to the polysilicon film.

(1st process condition)

Base temperature: 0 to 40°C

Supply amount of difluoromethane CH ₂ F ₂ gas: 10 to 500 SCCM

Supply amount of nitrogen trifluoride NF ₃ gas: 0 to 1000SCCM

Supply amount of nitrogen _N2 gas: 100 to 2500SCCM

Supply amount of oxygen _O2 gas: 2000 to 2500SCCM

Power: 1000～3000W

Pressure in process chamber: 300 to 1000mTorr

In addition, under the following second process conditions, the etching selectivity of the silicon nitride film to the polysilicon film is higher than the etching selectivity of the silicon nitride film to the silicon oxide film.

(2nd process condition)

Base temperature: 40 to 70°C

Supply amount of difluoromethane CH ₂ F ₂ gas: 10 to 500 SCCM

Supply amount of nitrogen trifluoride NF ₃ gas: 0 to 1000SCCM

Supply amount of nitrogen _N2 gas: 100 to 2500SCCM

Supply amount of oxygen _O2 gas: 100 to 2000SCCM

Power: 1000～3000W

Pressure in process chamber: 300 to 1000mTorr

FIG. 2 shows the etching selectivity ratio of the silicon nitride film with respect to the polysilicon film and the silicon oxide film when the etching process is performed in the range within the first process condition. FIG. 3 shows the etching selectivity ratio of the silicon nitride film with respect to the polysilicon film and the silicon oxide film when the etching process is performed within the range of the second process condition. 2 and 3, it can be seen that under the process conditions of FIG. 2, the etching selectivity ratio (180:1) of the silicon nitride film relative to the silicon oxide film is higher than the etching selectivity ratio (90:1) of the silicon nitride film relative to the polysilicon film. 1) High, under the process conditions of Figure 3, on the contrary, the etching selectivity ratio (170:1) of the silicon nitride film relative to the polysilicon film is higher than the etching selectivity ratio (90:1) of the silicon nitride film relative to the silicon oxide film. 1) Ratio.

According to the embodiments of the present invention, the etching selectivity ratio of the silicon nitride film relative to the silicon oxide film can be adjusted by adjusting the supply amount of oxygen gas or the temperature in the process chamber without changing the type of source gas. The relative size of the etch selectivity of the polysilicon film. The temperature adjustment of the process chamber is performed by changing the temperature of the susceptor. Therefore, when performing the etching process after supplying the source gas into the process chamber 110, it is not necessary to change the type of the source gas when the state of the silicon nitride film, silicon oxide film, and polysilicon film formed on the substrate W is changed. , the process is performed by adjusting the relative size of the etching selectivity ratio of the silicon nitride film to the silicon oxide film and the etching selectivity ratio of the silicon nitride film to the polysilicon film.

Fig. 4 shows that in a structural device that directly generates plasma inside a process chamber different from that of Fig. 1, difluoromethane CH ₂ F ₂ , oxygen O ₂ , nitrogen N ₂ and argon Ar gas are used as source gases. An experimental example of the etching selectivity ratio of a silicon nitride film to a silicon oxide film and a polysilicon film when performing an etching process.

According to the experimental example shown in Figure 4, it can be known that the temperature of the susceptor, the pressure in the process chamber, the supply amount of difluoromethane CH ₂ F ₂ , argon Ar, oxygen O ₂ and nitrogen N ₂ are provided as shown in Figure 4 When there is still power, the etching selectivity ratio of the silicon nitride film to the silicon oxide film is about 36:1, and the etching selectivity ratio of the silicon nitride film to the polysilicon film is about 48:1. Compared with the etching process, the etch selectivity is relatively very low.

FIG. 5 is a flowchart showing a method of etching a silicon nitride film using the apparatus 1 of FIG. 1 . The following etching method is performed by controlling the flow rate of the source gas, the temperature of the susceptor 120 , the pressure in the process chamber 110 , the magnitude of electric power, etc. by the controller.

Referring to FIG. 5 , first, a substrate W is placed on a susceptor 120 (step S10 ). When initially performing the etching process, the process is performed such that the etching selectivity of the silicon nitride film to the silicon oxide film is higher than the etching selectivity of the silicon nitride film to the polysilicon film according to the first process condition (step S20 ). Thereafter, when a predetermined time has elapsed, the substrate W is changed to the second process condition while maintaining the substrate W on the susceptor 120 (step S30 ). Thereafter, the process is performed under the second process condition such that the etching selectivity of the silicon nitride film to the polysilicon film is higher than the etching selectivity of the silicon nitride film to the silicon oxide film (step S40 ). When changing from the first process condition to the second process condition, the supply rate of oxygen gas and the temperature of the susceptor 120 or the supply rate of oxygen gas and the temperature of the susceptor 120 are all changed, difluoromethane, nitrogen trifluoride, The supply amount of nitrogen gas and the pressure in the process chamber 110 remain unchanged. The power supplied to generate plasma may be maintained constant or changed. When the process is completed, the substrate W is unloaded from the susceptor 120 (step S50 ).

However, unlike this, the supply amount of difluoromethane, nitrogen trifluoride, and nitrogen gas and the pressure in the process chamber 110 can also be controlled without affecting the etching selectivity of the silicon nitride film relative to the polysilicon film and the silicon nitride film. Changes are made within the range of changes in the relative size of the etching selectivity ratio to the silicon oxide film.

In addition, alternatively, in the initial stage of performing the etching process, the process is performed according to the second process condition, and after a certain period of time, the process is changed to the first process condition to perform the process.

Alternatively, the etching process may be performed while alternately applying the first process condition and the second process condition.

In the above example, when changing from the first process condition to the second process condition, the temperature (adjustment) in the process chamber 110 is performed after adjusting the temperature of the susceptor 121 . But not limited thereto, the temperature adjustment in the process chamber 110 can also be performed by adjusting the temperature of the chamber wall heater 118 , or by adjusting the temperatures of all the chamber wall heaters 118 and the susceptor 121 .

In addition, in the above-mentioned example, it was demonstrated that the supply amount of nitrogen gas was constant under the 1st process condition and the 2nd process condition. However, when the process conditions are changed from the first process conditions to the second process conditions, the supply amount of nitrogen gas may be changed. The supply amount of nitrogen gas can adjust the etching amount of the nitride film. For example, the amount of nitrogen gas to be supplied is increased to reduce the amount of etching of the nitride film. Therefore, it is possible to adjust the etching selectivity of the silicon nitride film relative to the polysilicon film and the etching selectivity ratio of the silicon nitride film relative to the silicon oxide film by utilizing the change in the supply amount of the nitrogen gas under the first process condition and the second process condition, Adjust its relative size.

The above description is merely an illustration of the technical idea of the present invention, and those who have ordinary knowledge in the technical field to which the present invention pertains can make various corrections and modifications without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustration only, and such embodiments do not limit the scope of the technical idea of the present invention. The protection scope of the present invention must be interpreted by the following claims, and it must be interpreted that all technical ideas within the scope equivalent to the claims are included in the scope of the present invention.

Claims (18)

1. a semiconductor making method, for being etched on substrate the nitride film formed, wherein,

Pedestal formed in processing chamber is placed substrate, in the outside of described processing chamber by the 1st Source gas produces plasma, and described plasma is supplied to described processing chamber,

Described 1st source gas comprises difluoromethane CH₂F₂, nitrogen N₂And oxygen O₂,

In the way that technique is carried out, change quantity delivered and the temperature of described processing chamber of described oxygen, make institute State any one in the quantity delivered of oxygen and the temperature of described processing chamber to increase, make another reduce,

Wherein, the temperature regulation of described processing chamber includes the temperature regulation of described pedestal,

And the quantity delivered of described oxygen is at the scope of 100 to 2000SCCM and 2000 to 2500SCCM Change between scope, the temperature of described pedestal the scope of 40 DEG C to 70 DEG C and 0 DEG C to 40 DEG C scope it Between change.

Semiconductor making method the most according to claim 1, it is characterised in that:

When changing the temperature of the quantity delivered of described oxygen and described processing chamber, described difluoromethane is supplied Amount remains constant.

Semiconductor making method the most according to claim 1, it is characterised in that:

When changing the temperature of the quantity delivered of described oxygen and described processing chamber, change described nitrogen gas Quantity delivered.

Semiconductor making method the most according to claim 1, it is characterised in that:

Described difluoromethane CH₂F₂The quantity delivered of gas is 10 to 500SCCM, described nitrogen N₂Gas Quantity delivered be 100 to 2500SCCM.

Semiconductor making method the most according to claim 4, it is characterised in that:

Pressure in described processing chamber is 300 to 1000mTorr, supplies to produce described plasma The electric power given is 1000 to 3000W.

Semiconductor making method the most according to claim 4, it is characterised in that:

The path supplying described plasma to described processing chamber is supplied the 2nd source gas,

Described 2nd source gas comprises Nitrogen trifluoride NF₃。

Semiconductor making method the most according to claim 6, it is characterised in that:

When etch process is carried out, the quantity delivered of described Nitrogen trifluoride is more than 0 and is below 1000SCCM.

8. a semiconductor making method, is forming polysilicon film, silicon oxide film and the substrate of silicon nitride film On, silicon nitride film, wherein,

When having loaded described substrate on the pedestal in processing chamber, by including difluoromethane CH₂F₂, nitrogen N₂And oxygen O₂The 1st source gas produce plasma, etch described silicon nitride film, By changing quantity delivered and the temperature of described processing chamber of described oxygen, regulate described silicon nitride film Relative to the etching selectivity of described silicon oxide film and described silicon nitride film relative to the erosion of described polysilicon film Carve the relative size selecting ratio,

Wherein, increase according to any one in the temperature of the quantity delivered and described processing chamber that make described oxygen, Another mode reduced remaining is made to change,

The temperature change of described processing chamber comprises the temperature change of described pedestal, and the quantity delivered of described oxygen Change between the scope and the scope of 2000 to 2500SCCM of 100 to 2000SCCM, described pedestal Temperature change between scope and the scope of 0 DEG C to 40 DEG C of 40 DEG C to 70 DEG C.

Semiconductor making method the most according to claim 8, it is characterised in that:

After the described plasma of outside generation of described processing chamber, it is supplied to described processing chamber.

Semiconductor making method the most according to claim 9, it is characterised in that:

When changing the temperature of the quantity delivered of described oxygen and described processing chamber, by the confession of described difluoromethane Give amount and the pressure remained constant in described processing chamber.

11. semiconductor making methods according to claim 9, it is characterised in that:

When changing the temperature of the quantity delivered of described oxygen and described processing chamber, change the supply of described nitrogen Amount.

12. according to Claim 8 to the semiconductor making method according to any one of 11, it is characterised in that:

Described difluoromethane CH₂F₂Quantity delivered be 10 to 500SCCM, the quantity delivered of described nitrogen is 100 to 2500SCCM.

13. semiconductor making methods according to claim 12, it is characterised in that:

Pressure in described processing chamber is 300 to 1000mTorr.

14. 1 kinds of semiconductor-fabricating devices, comprise:

Perform the technique unit of etch process；

To the plasma feed unit of described technique unit supply plasma, this plasma feed unit It is formed at the outside of described technique unit；With

Controller, this controller controls described technique unit and described plasma feed unit,

Described technique unit comprises: processing chamber；With

Having the pedestal of heater block, this pedestal is positioned at described processing chamber, supports substrate,

Described plasma feed unit comprises:

At the outside plasma chamber formed of described technique unit, the inside of this plasma chamber has Discharge space；

1st source gas supply part, the 1st source gas supply part supplies the 1st source gas to described discharge space；

Electric power applying unit, by this electric power applying unit provide electric power, with in described discharge space by the 1st source gas Body produces plasma；With

Inflow catheter, this inflow catheter provides and is supplied to described by the plasma of generation in described discharge space The path of processing chamber,

Described 1st source gas comprises difluoromethane CH₂F₂, nitrogen N₂And oxygen O₂,

Described controller makes the quantity delivered of described oxygen and the temperature of described pedestal become in the way that technique is carried out More, make any one in the quantity delivered of described oxygen and the temperature of described processing chamber increase, make another subtract It is few,

Wherein, the temperature that the temperature change of described processing chamber comprises described pedestal changes, and described oxygen Quantity delivered changes between the scope and the scope of 2000 to 2500SCCM of 100 to 2000SCCM, institute The temperature stating pedestal changes between scope and the scope of 0 DEG C to 40 DEG C of 40 DEG C to 70 DEG C.

15. semiconductor-fabricating devices according to claim 14, it is characterised in that:

Described plasma chamber is combined with described processing chamber on the top of described processing chamber,

Described technique unit comprises the baffle plate on the top being positioned at described pedestal, and this baffle plate is formed at above-below direction Multiple through holes.

16. semiconductor-fabricating devices according to claim 15, it is characterised in that:

Described plasma feed unit also comprises the 2nd source gas supply to path supply the 2nd source gas Portion, this path is the path that the described plasma produced in described discharge space flows to described processing chamber,

Described 2nd source gas comprises Nitrogen trifluoride NF₃。

17. 1 kinds of semiconductor making methods, it utilizes partly leading according to any one of claim 14 to 16 System manufacturing apparatus etches nitride film, wherein comprises:

The step of described 1st source gas is supplied to described discharge space；

The step of plasma is produced by described 1st source gas at described discharge space；

The described plasma produced in described discharge space is supplied the step of described processing chamber；With

By the step of the nitride film on substrate described in described plasma etching,

In the way that etch process is carried out, change quantity delivered and the temperature of described processing chamber of described oxygen, make Any one in the quantity delivered of described oxygen and the temperature of described processing chamber increases, and makes another reduce,

Wherein, the temperature that the temperature change of described processing chamber comprises described pedestal changes, and described oxygen Quantity delivered changes between the scope and the scope of 2000 to 2500SCCM of 100 to 2000SCCM, institute The temperature stating pedestal changes between scope and the scope of 0 DEG C to 40 DEG C of 40 DEG C to 70 DEG C.

18. semiconductor making methods according to claim 17, it is characterised in that:

Period, described difluoromethane CH is carried out at described etch process₂F₂Quantity delivered be 10 to 500SCCM, the quantity delivered of described nitrogen is 100 to 2500SCCM, the pressure in described processing chamber Being 300 to 1000mTorr, described electric power is 1000 to 3000W.