JP2008270348A - Dry etching apparatus and workpiece processing method - Google Patents

Abstract

In a process of forming a recess or a through hole in a workpiece, a dry process capable of shortening the time from the start of processing of a first workpiece to the start of processing of the next workpiece. An etching apparatus and a method for processing a workpiece are provided.
When a workpiece placed inside is subjected to a dry etching process and a protective film forming process alternately, and there is no workpiece inside for the purpose of forming a film on an inner wall. , A chamber 110 in which a film forming process is performed, cooling means 124, 124 a and 124 b for cooling the chamber 110, and a control unit 126 for controlling the cooling means 124. The control unit 126 operates the cooling unit 124 when the film forming process is performed. A heating unit 122 that is controlled by the control unit 126 and heats the chamber 110 may be provided. The control unit 126 operates the heating unit 122 when performing dry etching processing and protective film formation processing on the workpiece.
[Selection] Figure 1

Description

  The present invention relates to a dry etching apparatus for forming a recess or a through hole in a workpiece and a method for processing the workpiece. In particular, the present invention relates to a dry etching apparatus and a method for processing a workpiece that can shorten the time required to form a recess or a through hole.

One method for forming a recess or a through hole having a high aspect ratio in a substrate is a Bosch process method. In this method, dry etching treatment using a sulfur fluoride-based gas such as SF ₆ and formation of a sidewall protective film (deposition film) using a fluorocarbon-based gas such as CHF ₃ and C ₄ F ₈ (deposition) This method repeats the process (see US Pat. No. 5,501,893) and has a feature that etching with high anisotropy can be performed (see, for example, Patent Document 1).

  When performing the Bosch process method, the thickness of the protective film greatly affects the shape of the recess or the through hole. On the other hand, the deposition rate of the protective film varies depending on the state of film deposition on the inner wall of the chamber. As a method for stabilizing the film adhesion state on the inner wall of the chamber, there is a method in which a protective film is formed in a state where a dummy substrate is disposed in the chamber and the protective film is adhered to the inner wall of the chamber. The deposition rate of the protective film generally increases as the temperature decreases.

  On the other hand, in the dry etching process, the chamber is often preheated in order to suppress a decrease in etching stability due to an increase in the chamber temperature at the start of plasma discharge (see, for example, Patent Document 2).

US Pat. No. 5,501,893 JP 2002-93789 A (FIG. 1)

  As described above, in the dry etching process, the chamber is often preheated. On the other hand, the film formation speed generally increases as the temperature decreases. For this reason, when a film is deposited on the inner wall of the chamber, the deposition rate is slow, and the time required to form the film on the inner wall of the chamber is long. As a result, the time (1 cycle time) from the start of processing of the first workpiece to the start of processing of the next workpiece is increased, and the throughput of the workpiece is reduced. It was.

  The present invention has been made in consideration of the above-described circumstances, and its purpose is to start processing the first workpiece in the step of forming a recess or a through-hole in the workpiece and then start processing the first workpiece. An object of the present invention is to provide a dry etching apparatus and a processing method for a workpiece that can shorten the time until the processing of the workpiece is started.

In order to solve the above-described problems, a dry etching apparatus according to the present invention performs a dry etching process and a protective film forming process alternately on a workpiece disposed inside and forms a film on an inner wall. For the purpose, a chamber in which film formation is performed when the workpiece is not present inside,
Cooling means for cooling the chamber;
A control unit that controls the cooling unit, and the control unit operates the cooling unit when the film forming process is performed.

  According to this dry etching apparatus, when the film forming process is performed, the cooling unit operates, so that the film forming speed on the inner wall is increased. Therefore, the time required for forming the film on the inner wall of the chamber can be shortened. As a result, in the step of forming a recess or a through hole in a workpiece such as a substrate, the time from the start of processing of the first workpiece to the start of processing of the next workpiece is shortened. Can do.

  A heating unit that is controlled by the control unit and heats the chamber may be provided. And the said control part may operate the said heating means, when performing the said dry etching process and the said protective film formation process with respect to the said to-be-processed object.

In the dry etching apparatus according to the present invention, a dry etching process and a protective film forming process are alternately performed on a work piece disposed inside, and a film is formed on an inner wall. A chamber in which film formation is performed when there is no workpiece;
Cooling means for cooling the chamber;
Heating means for heating the chamber;
A control unit for controlling the cooling means;
Comprising
The control unit operates the heating unit to preheat the chamber when there is no workpiece and the film forming process is not performed, and the dry etching process and the protective film forming process are alternately performed. Sometimes the cooling means is activated.

  According to this etching apparatus, when the protective film is formed on the workpiece, the chamber is cooled, so that the growth rate of the protective film on the inner wall of the chamber is increased. Since the chamber is also cooled during the dry etching process, the etching rate of the protective film is reduced. For this reason, the frequency | count of the said film-forming process can be reduced. As a result, in the step of forming a recess or a through hole in a workpiece such as a substrate, the average time from the start of processing of the first workpiece to the start of processing of the next workpiece is shortened. be able to.

A method for processing a workpiece according to the present invention includes a step of cooling a chamber and forming a protective film on the inner wall of the chamber by performing a protective film forming process inside the chamber;
Placing a workpiece on which a mask film having an opening pattern is formed inside the chamber;
By alternately performing a dry etching process using the mask film as a mask and a protective film forming process on the mask film and in the opening pattern inside the chamber, a recess or a through hole is formed in the workpiece. Forming.

  In the step of forming the concave portion or the through hole in the workpiece, the chamber may be heated.

A processing method of a workpiece according to the present invention includes a step of disposing a workpiece on which a mask film having an opening pattern is formed inside the chamber;
By alternately performing a dry etching process using the mask film as a mask and a protective film forming process on the mask film and in the opening pattern inside the chamber, a recess or a through hole is formed in the workpiece. Forming, and
Comprising
The chamber is cooled in the step of forming a recess or a through hole in the workpiece.
.

  In the above-described method for processing a workpiece, the workpiece is, for example, a substrate.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the configuration of a dry etching apparatus used in a substrate processing method according to an embodiment of the present invention. The dry etching apparatus shown in this figure is an apparatus that forms a recess or a through hole in a substrate such as a silicon substrate by dry etching. When forming a through hole in a silicon substrate, the silicon substrate is used when forming a semiconductor chip having a through electrode in which a conductive material is embedded in the through hole. The semiconductor chips are three-dimensionally mounted by being stacked.

  In this dry etching apparatus, a stage 111 on which the substrate 100 is placed is provided inside the chamber 110. The stage 111 is provided with a heater (not shown) for heating. An etching gas (process gas) is introduced into the chamber 110 from a gas inlet 110a. The etching gas introduced into the chamber 110 is plasma-discharged by a voltage applied from an electrode (not shown), and the substrate 100 is dry-etched. The atmospheric gas in the chamber 110 is exhausted from the exhaust port 110b. A film 112 is attached to the inner wall of the chamber 110.

  A heater 122 for heating the chamber 110 is provided above the upper surface of the chamber 110. A water cooling pipe 124 b for cooling the chamber 110 is embedded in at least the side wall of the chamber 110. The water cooling pipe 124b is connected to a water pipe 124a outside the chamber 110, and cooling water is supplied by a pump 124 connected to the water pipe 124a. The cooling water may be a circulation type or may not be a circulation type. The heater 122 and the pump 124 are controlled by the control unit 126. Note that the control unit 126 also controls the heater for heating the stage 111 independently from the heater 122 and the pump 124.

  2A and 2B are cross-sectional views for explaining a method of forming a high aspect ratio recess 100a in the substrate 100 by the Bosch process method. First, as shown in FIG. 2A, a mask film 102 having an opening pattern is formed over a substrate 100. Next, dry etching is performed using the mask film 102 as a mask. As a result, a recess 100 a is formed in the substrate 100. In this state, the recess 100a does not have a sufficient aspect ratio.

  Next, as shown in FIG. 2B, a protective film 103 is thinly formed on the sidewall of the recess 100a and on the mask film 102. At this time, the protective film 103 may also be formed on the bottom surface of the recess 100a.

Next, as shown in FIG. 2C, dry etching is performed again. The dry etching conditions are such that the etching rate of the protective film 103 is slower than the etching rate of the substrate 100. Thereby, the aspect-ratio of the recessed part 100a becomes high.
Thereafter, the steps shown in FIGS. 2B and 2C are repeated as many times as necessary to make the recesses 100a have the required aspect ratio.

  FIG. 3 is a flowchart for explaining a first example of a method for performing the process shown in FIG. 2 using the dry etching apparatus shown in FIG. In the example shown in this drawing, the mask film 102 shown in FIG. 2 is formed on the substrate 100 before the substrate 100 is inserted into the chamber 110.

While the substrate 100 is not processed, the controller 126 of the dry etching apparatus operates the heater 122 to preheat the chamber 110 (S2). Then, before the substrate 100 is processed, a dummy wafer is carried into the chamber 110. In addition, the control unit 126 operates the pump 124 to cool the chamber 110. In this state, a fluorocarbon gas such as CHF ₃ or C ₄ F ₈ is introduced into the chamber 110 as a process gas, and this gas is plasma-discharged. As a result, a film is formed on the inner wall of the chamber 110, and the film 112 becomes thick (S4). In this example, the film forming process on the inner wall of the chamber 110 uses the same gas as the protective film forming process described later. Thereafter, the dummy wafer is unloaded.

  Since the chamber 110 is cooled, the deposition rate of the film 112 is high. For this reason, the time until the film 112 is made to have a required thickness is shortened.

  In the film forming process on the inner wall of the chamber 110, the chamber 110 does not always need to be cooled. For example, the pump 124 may be operated only while a dummy wafer is loaded. In this way, the chamber 110 is not overcooled, and variation in the etching rate can be suppressed in the etching process described later.

  In the example shown in FIG. 1, the chamber 110 has a configuration in which the entire side wall is cooled. However, the upper wall may be cooled by embedding a water cooling pipe in the upper wall. Alternatively, a water-cooled tube may be embedded only in a portion of the side wall and the upper wall where the film 112 is difficult to form, and this portion may have a lower temperature than other portions.

Next, the substrate 100 on which the mask film 102 is formed is carried into the chamber 110 (S6). Next, the control unit 126 operates the heater 122 to heat the chamber 110. In this state, the etching process described with reference to FIG. 2B and the protective film formation process described with reference to FIG. 2C are repeated as many times as necessary. The etching gas in the etching process is a sulfur fluoride-based gas such as SF ₆ , and dry etching is performed by plasma discharge of this gas. In the protective film formation process, a fluorocarbon gas such as CHF ₃ or C ₄ F ₈ is introduced, and the protective film 103 is formed by plasma discharge of this gas. Thereby, the recessed part 100a is formed in the board | substrate 100 (S8). Note that the film 112 is also etched in the etching process for forming the recess 100a. Thereafter, the substrate 100 is unloaded from the chamber 110 (S10).

  FIG. 4 is a flowchart for explaining a second example of the method for performing the process shown in FIG. 2 using the dry etching apparatus shown in FIG. Hereinafter, the same step number is attached | subjected about the process similar to the 1st example shown in FIG. 3, and description is abbreviate | omitted.

  After the processing shown in S2 to S4 in FIG. 3 is performed, the substrate 100 on which the mask film 102 is formed is carried into the chamber 110 (S6). Next, the control unit 126 operates the heater 122 to heat the chamber 110 until plasma is generated (ignited) (S81). After the plasma is generated, the control unit 126 stops the operation of the heater 122 and operates the pump 124 to cool the chamber 110. In this state, the etching process and the protective film forming process described with reference to FIG. 2B are alternately performed a predetermined number of times (S82).

Since the chamber 110 is cooled, the deposition rate of the film 112 in the protective film formation process is high. On the other hand, the etching rate of the film 112 in the etching process is not changed compared to the conventional one. For this reason, in the formation process of the recessed part 100a, the film | membrane 112 becomes difficult to reduce.
And after the recessed part 100a is formed in the board | substrate 100, the board | substrate 100 is carried out from the chamber 110 (S10).

  As described above, according to the present embodiment, as described with reference to FIGS. 3 and 4, since the chamber 110 is cooled in the film forming process on the inner wall of the chamber 110, the film 112 is formed at a high rate. . For this reason, the time until the film 112 is made to have a required thickness is shortened. Therefore, it is possible to shorten the time from the start of forming the recess 100a in the substrate 100 to the start of forming the recess 100a in the next substrate 100. As a result, the throughput of the substrate 100 is improved.

Further, as long as the film 112 has a necessary thickness, the process shown in S4 need not be performed every time the substrate 100 is replaced. According to the example described with reference to FIG. 4, when the protective film 103 is formed on the substrate 100, the growth rate of the film 112 on the inner wall of the chamber 110 is increased, while the film 112 is etched when the substrate 100 is etched. The speed does not change. For this reason, the frequency | count of the process shown to S4 can be reduced.
Therefore, the throughput of the substrate 100 is further improved.

  FIG. 5 is an exploded perspective view for explaining the configuration of the droplet discharge head 1 according to the second embodiment, and FIG. 6 is a part of a perspective configuration view of the droplet discharge head 1 as viewed from below. FIG. The droplet discharge head 1 of the present embodiment discharges a functional liquid from a nozzle with droplets. As shown in FIG. 5, the droplet discharge head 1 includes a nozzle plate 20 having a nozzle opening 15 through which droplets are discharged, and a flow path forming substrate having an ink supply path 14 connected to the upper surface of the nozzle plate 20. 10, an elastic plate 50 connected to the upper surface of the flow path forming substrate 10, a reservoir forming substrate 30 connected to the upper surface of the elastic plate 50 to form the reservoir portion 31, and the reservoir forming substrate 30. The piezoelectric element 300 that displaces the elastic plate 50 and the drive circuit unit 60 for driving the piezoelectric element 300 are provided.

  The flow path forming substrate 10 is formed by processing a silicon single crystal substrate, and the upper surface side (+ Z direction) of the flow path forming substrate 10 is made of silicon dioxide formed by thermal oxidation. An elastic plate 50 of 1 to 2 μm is formed.

  In addition, as shown in FIG. 6, the flow path forming substrate 10 is formed with a plurality of substantially comb-shaped opening regions in plan view, and a portion formed by extending in the X direction among these opening regions. However, the pressure generating chamber (cavity) 12 is formed by being surrounded by the nozzle plate 20 and the elastic plate 50. During the operation of the droplet discharge head 1, the functional liquid is accommodated in the pressure generation chamber 12, and the functional liquid is discharged from the nozzle opening 15 by the pressure applied to the pressure generation chamber 12.

  In addition, the pressure generation chambers 12 partitioned by the plurality of partition walls 11 are arranged in two rows in the X direction, and a portion formed to extend in the Y direction in the drawing in a substantially comb-shaped opening region in a plan view corresponds to each pressure. A communication portion 13 for communicating the generation chamber 12 is formed. As shown in FIG. 1, the communication portion 13 communicates with the reservoir portion 31 of the reservoir forming substrate 30 and constitutes a part of the reservoir 40 that functions as a common ink chamber. Here, the reservoir 40 is a space for preliminarily holding the functional liquid (ink) supplied to the pressure generating chamber 12.

  In addition, an ink supply path 14 which is a part of the communication portion 13 is provided at one end of each pressure generation chamber 12, and the pressure generation chambers 12 are communicated by the communication portion 13. Each ink supply path 14 that communicates with one end of each pressure generation chamber 12 is formed shallower than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12.

  Among the configurations described above, the pressure generation chamber 12 and the communication portion 13 of the flow path forming substrate 10 are manufactured by the method described in FIG. 3 or FIG. 4 of the first embodiment. That is, the substrate 100 shown in FIG. 2 of the first embodiment corresponds to the dew formation substrate 10 of this embodiment, and the recess 100a shown in FIG. 2 is provided in the pressure generation chamber 12 and the communication portion 13 of this embodiment. Equivalent to.

  As described above, in this embodiment, the pressure generating chamber 12 and the communication portion 13 included in the flow path forming substrate 10 of the liquid ejection head 1 are manufactured by the method shown in FIG. 3 or FIG. 4 of the first embodiment. The throughput of the process of forming the pressure generating chamber 12 and the communication portion 13 on the flow path forming substrate 10 is improved.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the first embodiment, a thermometer that measures the temperature of the chamber 110 may be provided, and the control unit 126 may control the heater 122 and the pump 124 based on the measured value of the thermometer. In the second example of the first embodiment, the controller 126 does not have to operate the heater 122 when performing the etching process.

1 is a schematic cross-sectional view showing a configuration of a dry etching apparatus used in an embodiment. Each drawing is a cross-sectional view illustrating a method of forming the recess 100a in the substrate 100 by the Bosch process method. The flowchart for demonstrating the 1st example of the method of performing the process shown in FIG. 2 using the dry etching apparatus shown in FIG. The flowchart for demonstrating the 2nd example of the method of performing the process shown in FIG. 2 using the dry etching apparatus shown in FIG. FIG. 6 is an exploded perspective view for explaining a configuration of a droplet discharge head 1 according to a second embodiment. FIG. 3 is a partially cutaway perspective view of the droplet discharge head 1 as viewed from below.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid discharge head, 10 ... Flow dew formation board | substrate, 11 ... Partition, 12 ... Pressure generating chamber, 13 ... Communication part, 14 ... Ink supply path, 15 ... Nozzle opening, 20 ... Nozzle plate, 30 ... Reservoir formation board, 31 DESCRIPTION OF SYMBOLS ... Reservoir part, 40 ... Reservoir, 50 ... Elastic plate, 100 ... Substrate, 100a ... Recess, 102 ... Mask film, 103 ... Protective film, 110 ... Chamber, 110a ... Gas inlet, 111 ... Stage, 112 ... Membrane, 122 ... Heater, 124 ... Pump, 124a ... Water pipe, 124b ... Water-cooled pipe, 126 ... Control unit, 300 ... Piezoelectric element

Claims (7)

A dry etching process and a protective film forming process are alternately performed on the workpiece disposed inside, and a film forming process is performed when the workpiece is not present inside, for the purpose of forming a film on the inner wall. A chamber in which
Cooling means for cooling the chamber;
A control unit for controlling the cooling means;
Comprising
The control unit is a dry etching apparatus that operates the cooling unit when the film forming process is performed. Controlled by the control unit, comprising heating means for heating the chamber;
The dry etching apparatus according to claim 1, wherein the control unit operates the heating unit when performing the dry etching process and the protective film forming process on the workpiece. A chamber in which a dry etching process and a protective film forming process are alternately performed on a workpiece disposed inside;
Cooling means for cooling the chamber;
Heating means for heating the chamber;
A control unit for controlling the cooling means;
Comprising
The control unit operates the heating unit to preheat the chamber when there is no workpiece and the film forming process is not performed, and the dry etching process and the protective film forming process are alternately performed. A dry etching apparatus that sometimes operates the cooling means. Forming a protective film on the inner wall of the chamber by cooling the chamber and performing a protective film forming process inside the chamber;
Placing a workpiece on which a mask film having an opening pattern is formed inside the chamber;
By alternately performing a dry etching process using the mask film as a mask and a protective film forming process on the mask film and in the opening pattern inside the chamber, a recess or a through hole is formed in the workpiece. Forming, and
A processing method for a workpiece comprising:   The processing method of the workpiece according to claim 4, wherein the chamber is heated in the step of forming the recess or the through hole in the workpiece. Forming a protective film on the inner wall of the chamber by cooling the chamber and performing a protective film forming process inside the chamber;
Placing a workpiece on which a mask film having an opening pattern is formed inside the chamber;
By alternately performing a dry etching process using the mask film as a mask and a protective film forming process on the mask film and in the opening pattern inside the chamber, a recess or a through hole is formed in the workpiece. Forming, and
Comprising
A method for processing a workpiece, wherein the chamber is cooled in a step of forming a recess or a through hole in the workpiece.   The method for processing a workpiece according to any one of claims 4 to 6, wherein the workpiece is a substrate.

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