KR101276482B1 - Etching method and etching apparatus - Google Patents

Abstract

The 2nd surface which is a back surface is etched, suppressing or preventing the etching of the 1st surface (for example, main surface) of the to-be-processed substrate containing silicon-containing materials, such as a glass substrate. The substrate 9 to be processed is placed in a processing atmosphere containing hydrogen fluoride and water. By the adjusting means including the heater 21, the temperature of the first surface 9a of the substrate 9 to be higher than the condensation point of hydrogen fluoride and water in the processing atmosphere, and the second surface 9b of the second surface 9b. Adjust the temperature to be below the condensation point.

Description

Etching Method and Apparatus {ETCHING METHOD AND ETCHING APPARATUS}

TECHNICAL FIELD The present invention relates to a method and apparatus for etching a substrate to be processed containing a silicon content, and more particularly to a method and apparatus suitable for etching to the extent that the back surface of a glass substrate is lightly roughened.

For example, Patent Documents 1 and 2 describe etching a silicon-containing substance on the surface of a glass substrate by bringing a processing gas containing hydrogen fluoride (HF) into contact with the glass substrate. The process gas is formed by adding water (H ₂ O) to a source gas containing a fluorine compound such as CF ₄ , for example, and then plasmaping the source gas by atmospheric pressure discharge. Hydrogen fluoride is produced by plasma (Scheme 1).

<Reaction Scheme 1>

When the processing gas contacts the glass substrate, hydrogen fluoride and water condense, and a condensation layer of hydrofluoric acid is formed on the surface of the glass substrate. Moreover, the etching reaction shown, for example in following Reaction Formula 2 arises, and the silicon-containing material of the surface of a glass substrate is etched.

<Reaction Scheme 2>

International publication WO2008 / 102807 Japanese Patent Laid-Open No. 2007-294642

The etching process technique disclosed in the said patent documents 1, 2 etc. can be applied, for example to the process of lightly roughening the back surface of a glass substrate. By lightly roughening the back surface, the glass substrate is placed on the stage, the main surface (surface on the surface side) is surface treated, and then the glass substrate can be easily separated from the stage when taken out from the stage.

It is preferable that the roughness of the back surface of the glass substrate by the said etching process is as small as possible in the range which can remove easily a glass substrate from a stage. If the degree of roughness is too large, it is difficult to adhere the glass substrate to the stage during the surface treatment of the subsequent main surface, or there is a fear that the optical characteristics of the glass substrate are impaired.

However, it is thought that the processing gas for etching also contacts the main surface of the glass substrate by diffusion. If so, even the principal surface is roughened.

This invention is made | formed in view of the above-mentioned circumstances, and the objective is to suppress or prevent the etching of the 1st surface (for example, main surface) of the to-be-processed substrate containing silicon-containing materials, such as a glass substrate, It is for etching the 2nd surface which is a back surface.

In order to solve the above problems, the method of the present invention includes a silicon-containing material, and a method of etching a substrate under treatment at atmospheric pressure having a first surface and a second surface which is the back surface of the first surface,

Placing the substrate to be treated in a processing atmosphere containing hydrogen fluoride vapor and water vapor;

The temperature of the first surface is adjusted to be higher than the condensation point of hydrogen fluoride and water in the treatment atmosphere, and the temperature of the second surface is adjusted to be below the condensation point.

In the second surface of the substrate to be treated, hydrogen fluoride and water condense on the second surface to form a condensation layer of hydrofluoric acid on the second surface by the relationship between the condensation point and the temperature of the second surface. Thereby, the etching reaction of the silicon-containing thing which comprises a 2nd surface arises, and a 2nd surface can be etched (including a roughening). On the other hand, in the first surface, the formation of the condensation layer can be avoided by the relationship between the condensation point and the temperature of the first surface. Therefore, etching of a 1st surface can be suppressed or prevented.

It is preferable to make the temperature of the said 1st surface into 0 degreeC-40 degreeC high temperature above the said condensation point. More preferably, the temperature of the first surface is 5 ° C to 30 ° C higher than the condensation point.

By lowering the temporary temperature of the first surface and further reducing the amount of heat to be applied to the first surface, it is possible to avoid or suppress the transfer of heat to the second surface, thereby preventing or suppressing the temperature rise of the second surface. Therefore, the temperature of a 2nd surface can be reliably made below the said condensation point. Therefore, the second surface can be reliably etched while reliably preventing or suppressing etching of the first surface.

It is preferable to make the temperature of the said 2nd surface into 0 degreeC-10 degreeC low temperature from the said condensation point.

By lowering the difference between the temperature of the condensation point and the second surface, if the first surface is slightly heated, the temperature of the first surface can be higher than the condensation point. By lowering the temporary temperature of the first surface and further reducing the amount of heat to be applied to the first surface, it is possible to avoid or suppress the transfer of heat to the second surface, thereby preventing or suppressing the temperature rise of the second surface. Therefore, the temperature of the said 2nd surface can be reliably made below the said condensation point. Therefore, the second surface can be reliably etched while reliably preventing or suppressing etching of the first surface.

The substrate to be processed is brought into the processing space from an inlet continuous to the processing space in which the processing atmosphere exists, and the substrate to be processed is taken out from the outlet opening continuous to the processing space, and the vicinity of the inlet is near. And gas may be sucked in the vicinity of the outlet port.

Thereby, before outside air reaches a process space through an inlet or an outlet, it can suck and exhaust in the vicinity of an inlet or an outlet, and can prevent an outside air from entering into a process space. The flow rate and flow rate of the inflowing outside air are varied depending on the loading and unloading of the substrate to be processed. Even if there is such a fluctuation, it is possible to prevent the mixing of outside air into the processing atmosphere by the above suction, so that the gas composition in the processing atmosphere and the hydrogen partial pressure of the hydrogen fluoride and the partial pressure of water vapor can be maintained to be substantially the same as those of the processing gas itself. As a result, the etching process of a 2nd surface can be prevented from becoming nonuniform. Moreover, even if the humidity of the outside air is high relative to the humidity of the processing atmosphere, the humidity of the processing atmosphere on the first surface side can be prevented from rising, and thus the condensation layer can be prevented from being formed on the first surface. Therefore, etching to even a 1st surface can be avoided.

An apparatus of the present invention includes a silicon-containing material, and is an apparatus for etching a substrate to be processed having a first surface and a second surface that is a rear surface of the first surface in the processing space near atmospheric pressure and humidity greater than 0%,

A extraction nozzle for supplying a processing gas containing at least hydrogen fluoride of hydrogen fluoride and water into the processing space to contact at least the second surface of the substrate to be processed;

And adjusting means for adjusting the temperature of the first surface to be higher than the condensation point of hydrogen fluoride and water in the processing space, and the temperature of the second surface to be below the condensation point.

The processing gas from the extraction nozzle is mixed with the processing atmosphere in the processing space. The treatment gas contains at least hydrogen fluoride in hydrogen fluoride and water and the humidity of the treatment space is greater than 0%, so that the treatment atmosphere contains hydrogen fluoride vapor and water vapor. This processing atmosphere contacts the to-be-processed object. At this time, on the second surface of the workpiece, hydrogen fluoride and water in the processing atmosphere are condensed on the second surface of the workpiece by adjusting the relationship between the condensation point and the temperature of the second surface by the adjusting means. A condensation layer of hydrofluoric acid is formed. Therefore, the etching reaction of the silicon-containing thing which comprises a 2nd surface arises, and a 2nd surface can be etched (including a roughening). On the other hand, in the first surface of the workpiece, by controlling the relationship between the condensation point and the temperature of the first surface by the adjusting means, it is possible to avoid condensation of hydrogen fluoride and water in the processing atmosphere on the first surface. Therefore, formation of a condensation layer of hydrofluoric acid can be avoided. Therefore, the etching reaction of the silicon-containing thing which comprises a 1st surface can be suppressed or prevented.

Humidity of the said processing space may exceed 0% and may be 100% RH or less.

The adjusting means may be to control the temperature of the first surface of the substrate to be treated, to control the temperature of the second surface, to control the hydrogen fluoride partial pressure or the steam partial pressure of the processing gas, or to process the processing space. It may be to control the partial pressure of steam in the processing atmosphere in the interior, or may be to control the partial pressure of steam in the outside air flowing into the processing space.

The adjusting means includes a heater disposed close to the position on the side opposite to the ejection nozzle with the position where the substrate to be processed is disposed in the processing space interposed therebetween, wherein a set temperature of the heater is greater than the condensation point; It is preferable that it is more than 0 degreeC-60 degreeC high temperature.

Thereby, the temperature of the 1st surface of a to-be-processed substrate can be made high temperature more reliably than the condensation point of hydrogen fluoride and water of a process atmosphere. By lowering the temporary temperature of the first surface and further reducing the amount of heat to be applied to the first surface, it is possible to avoid or suppress the transfer of heat to the second surface, thereby preventing or suppressing the temperature rise of the second surface. Therefore, the temperature of the said 2nd surface can be reliably made below the said condensation point. Thereby, a 2nd surface can be reliably etched, reliably suppressing or preventing the etching of a 1st surface.

When the substrate to be processed is moved relative to the ejection nozzle, it is preferable to set the set temperature of the heater in consideration of the moving speed.

For example, when the moving speed is relatively large, the set temperature is made relatively larger than the desired temperature of the first surface. As a result, the time required for the first surface to reach the desired temperature can be shortened. On the other hand, since the moving speed is relatively large, the processing can be finished before the second surface is even higher than the condensation point.

When the moving speed is relatively small, the set temperature may be made almost equal to the desired temperature. Thereby, it can avoid that the temperature of a to-be-processed substrate greatly exceeds the said desired temperature. On the other hand, when the moving speed is small, the heating time becomes long, but the temperature of the second surface can be kept below the condensation point by setting the set temperature and the desired temperature to a temperature slightly higher than the condensation point.

Preferably, the adjusting means sets the temperature of the second surface to 0 ° C to 10 ° C lower than the condensation point.

By reducing the difference between the condensation point of hydrogen fluoride and water in the processing atmosphere and the temperature of the second surface, if the first surface is slightly heated, the temperature of the first surface can be higher than the condensation point. By lowering the temporary temperature of the first surface and further reducing the amount of heat to be applied to the first surface, it is possible to avoid or suppress the transfer of heat to the second surface, thereby preventing or suppressing the temperature rise of the second surface. Therefore, the temperature of the said 2nd surface can be reliably made below the said condensation point. Therefore, the second surface can be reliably etched while reliably suppressing or preventing the etching of the first surface.

Here, the vicinity of atmospheric pressure refers to the range of 1.013 × 10 ⁴ to 50.663 × 10 ⁴ Pa, and considering the ease of pressure adjustment and the simplified device configuration, 1.333 × 10 ⁴ to 10.664 × 10 ⁴ Pa is preferable, and 9.331 × 10 ⁴ to 10.397 × 10 ⁴ Pa is more preferable.

According to this invention, the 2nd surface which is a back surface can be etched, suppressing or preventing the etching of the 1st surface of a to-be-processed substrate.

1 is a side sectional view showing an atmospheric pressure etching apparatus according to a first embodiment of the present invention.
FIG. 2 is a front sectional view of a processing part of the atmospheric etching apparatus along the line II-II of FIG. 1. FIG.
3 is a side sectional view showing an atmospheric pressure etching apparatus according to a second embodiment of the present invention.
4 is a front cross-sectional view of the atmospheric pressure etching apparatus according to the second embodiment along the IV-IV line in FIG. 3.
5 is a side sectional view showing an atmospheric pressure etching apparatus according to a third embodiment of the present invention.
FIG. 6 is a plan sectional view of a processing unit of the atmospheric pressure etching apparatus according to the third embodiment along the line VI-VI of FIG. 5.
FIG. 7 is a side view showing gas flow fluctuation when the substrate to be processed is conveyed in the third embodiment, (a) is a state in which a substrate is not loaded, and (b) is an end portion of the substrate to be processed. (C) is a state where the to-be-processed board | substrate was carried to the inside of a process space.
FIG. 8 is a graph showing the etching rates of the first and second surfaces for each heater set temperature in Example 1. FIG.
FIG. 9A is a graph showing the distribution in the substrate width direction of the etching rates of the first and second surfaces when the heater set temperature is 25 ° C. in Example 1. FIG.
FIG. 9B is a graph showing the distribution in the substrate width direction of the etching rates of the first and second surfaces when the heater set temperature is 30 ° C. in Example 1. FIG.
FIG. 10A is a graph showing the distribution in the substrate width direction of the etching rates of the first and second surfaces when the heater set temperature is 35 ° C. in Example 1. FIG.
FIG. 10B is a graph showing the distribution in the substrate width direction of the etching rates of the first and second surfaces when the heater set temperature is 45 ° C. in Example 1. FIG.
11 is a graph showing condensation conditions for each temperature of HF and H ₂ O. FIG.
12 is a graph showing the condensation temperature of each one of the HF and H ₂ O the etching apparatus of the third embodiment as an example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show a first embodiment of the present invention. The substrate 9 to be processed is a glass substrate that should be a semiconductor device such as a flat panel display. A glass substrate (9) contains as a main component a silicon-containing material, such as SiO _2. The thickness of the glass substrate 9 is about 0.5 mm-about 0.7 mm, for example. The glass substrate 9 has a rectangular flat plate shape, and has the 1st surface 9a (main surface) of the surface side, and the 2nd surface 9b (back surface) which is its back surface. The first surface 9a is a main surface on which various electronic element layers such as an insulating layer, a conductive layer, and a semiconductor layer should be formed. The second surface 9b is the back surface to be subjected to the roughening (etching) process by the atmospheric pressure etching apparatus 1. After roughening the 2nd surface 9b, the surface treatment for forming the said various electronic element layers is performed with respect to the 1st surface 9a.

As shown in FIG. 1, the atmospheric pressure etching apparatus 1 is equipped with the source gas supply means 10, the process part 20, and the conveyance means 30. As shown in FIG. The raw material gas supply means 10 includes the fluorine-based raw material supply part 11 and the water addition part 12.

The fluorine-type raw material supply part 11 supplies the raw material gas used as the process gas (etching agent) for etching. The source gas includes a fluorine-containing gas and a carrier gas. CF ₄ is used as the fluorine-containing gas. Instead of CF ₄ as the fluorine-containing gas, other PFCs (perfluorocarbons) such as C ₂ F ₆ , C ₃ F ₆ , and C ₃ F ₈ may be used, and CHF ₃ , CH ₂ F ₂ , CH ₃ F and the like. HFC (hydrofluorocarbon) may be used, or fluorine-containing compounds other than PFC and HFC such as SF ₆ , NF ₃ and XeF ₂ may be used.

In addition to the function of conveying the fluorine-containing gas, the carrier gas has a function as a diluent gas for diluting the fluorine-containing gas, a function as a discharge gas for generating a plasma discharge described later. As the carrier gas, an inert gas is preferably used. As inert gas used as a carrier gas, rare gases, such as helium, argon, neon, and xenon, and nitrogen are mentioned. Argon (Ar) is used here as a carrier gas. The flow rate ratio (CF ₄ : Ar) of the fluorine-containing gas and the carrier gas is preferably 1: 1000 to 1:10. The carrier gas may be omitted.

The water addition unit 12 adds water (H ₂ O) to the source gas (CF ₄ + Ar) to humidify the source gas. By adjusting the amount of hydrogenation, the partial pressure of water vapor of the raw material gas and the partial pressure of hydrogen fluoride and the partial pressure of steam of the processing gas are adjusted. The water addition part 12 is comprised with the humidifier provided with tanks, such as a thermostat, for example. Liquid water is stored in this tank. The raw material gas from the supply part 11 is supplied to the upper part than the water surface of the said tank, and is mixed with the saturated water vapor of the said upper part. Alternatively, water vapor may be added to the source gas by bubbling the source gas from the supply section 11 in the water in the tank. The temperature of the tank can be adjusted to adjust the vapor pressure, thereby adjusting the amount of water added. It is preferable to adjust the water addition amount of the water addition part 12 and also the dew point of a process gas so that the etching process performance of the 2nd surface 9b may be satisfied.

The dew point of the raw material gas before water addition is preferably -40 ° C or lower. The dew point of −40 ° C. is about 0.03 Torr in terms of the partial pressure of water vapor, about 0.004% in terms of volume concentration, and the amount of water vapor in the source gas is almost equal to zero.

The amount of water in the source gas after the water addition can be calculated from the dew point of the source gas before the water addition and the amount of vaporization of water in the water addition unit 12. The amount of water in the source gas after water addition can also be measured using a Fourier Transform infrared spectrometer (FTIR).

As shown in FIG. 1, the processing unit 20 includes a top plate 21, a bottom plate 22, a blowout nozzle 40, and a suction nozzle 50. The upper plate 21 has a horizontal plate shape. The width dimension along the direction orthogonal to the surface of FIG. 1 in the upper plate 21 (hereinafter referred to as the "y direction") is slightly larger than the width dimension in the y direction of the substrate 9 to be processed. The upper plate 21 is composed of a plate heater, and also serves as a temperature adjusting means described later. The housing of the upper plate 21, that is, the plate heater 21, is made of metal such as aluminum. It is preferable to form a resin film having high fluorine resistance and plasma resistance, such as polytetrafluoroethylene, on at least the lower surface of the upper plate 21.

The bottom plate 22 has a horizontal plate shape and is arranged in parallel under the top plate 21. The width dimension of the bottom plate 22 in the y direction (left and right direction in FIG. 2) is slightly larger than the width dimension of the substrate 9 in the y direction. The bottom plate 22 may be comprised with metals, such as aluminum, may be comprised with resin, and may be comprised with the glass plate. In the case where the bottom plate 22 is made of a metal, it is preferable to form a resin film having high fluorine resistance and plasma resistance such as polytetrafluoroethylene on at least an upper surface thereof.

The extraction nozzle 40 is arrange | positioned at the one end part (right side in FIG. 1) of the left-right direction (henceforth "x direction") of FIG. 1 in the process part 20. FIG. As shown in FIG. 1 and FIG. 2, the ejection nozzle 40 has a container shape extending in the y direction. The ejection opening 41 is formed in the upper end surface of the ejection nozzle 40. The ejection opening 41 has a slit shape extending in the y direction. The length along the y direction of the ejection opening 41 is slightly larger than the width dimension along the y direction of the substrate 9 to be processed.

The extraction nozzle 40 is in contact with one end (right side in FIG. 1) of the bottom plate 22 in the x direction. An upper end face of the ejection nozzle 40 is flush with the upper face of the bottom plate 22. One end (right side in FIG. 1) of the upper plate 21 extends to one end side (right side in FIG. 1) than the bottom plate 22 and covers the upper side of the ejection nozzle 40. An inlet 26 is formed between one end of the upper plate 21 and the ejection nozzle 40.

The suction nozzle 50 is arrange | positioned at the other end part (left side in FIG. 1) of the x direction in the process part 20. As shown in FIG. The suction nozzle 50 has a container shape extending in the y direction. The suction port 51 is opened in the upper end surface of the suction nozzle 50. The suction port 51 has a slit shape extending in the y direction. The length along the y direction of the suction port 51 is slightly larger than the width dimension along the y direction of the substrate 9 to be processed.

The suction nozzle 50 is in contact with the other end portion (left side in FIG. 1) of the bottom plate 22 in the x direction. The upper end face of the suction nozzle 50 is made flush with the upper face of the bottom plate 22. The other end (left side in FIG. 1) of the upper plate 21 extends to the other end side than the bottom plate 22, and covers the upper side of the suction nozzle 50. An outlet 27 is formed between the other end of the upper plate 21 and the suction nozzle 51.

The processing unit internal space 29 is formed between the upper top plate 21 of the processing unit 20 and the lower configuration portions 22, 40, 50. A carry-in port 26 is connected to one end (right side in FIG. 1) of the space 29 in the processing section. The delivery port 26 is connected to the other end part (left side in FIG. 1) of the space 29 in a process part. Both ends of the processing unit inner space 29 in the x direction are connected to the space outside the processing unit 20 via the inlet and outlet ports 26 and 27. As shown in FIG. 2, both ends of the y direction of the space 29 in a process part are respectively blocked by the side wall 24. As shown in FIG.

As shown in FIG. 1, the portion from the position in the x direction of the ejection opening 41 to the position in the x direction of the suction port 51 in the processing unit internal space 29 constitutes the processing space 23. The upper top plate 21, the lower components 22, 40, 50 and the both side walls 24 of the processing unit 20 constitute a processing space partition. The processing space 23 extends from the blowout port 41 to the delivery opening 26 through the space 29 in the processing section on one end side in the x direction. In addition, the processing space 23 extends from the suction port 51 to the discharge port 27 via the processing unit internal space 29 on the other end side in the x direction. The thickness d ₀ of the processing space 23 is equal to the distance between the lower surface of the upper plate 21 and the upper surface of the bottom plate 22, for example, d ₀ = 5 mm to about 10 mm.

The rectifying part 42 is formed in the lower part of the extraction nozzle 40. Although not shown in detail, the rectifying part 42 includes a chamber extending in the y direction or a slit or a row of a plurality of small holes arranged in the y direction. The source gas (CF ₄ + Ar + H ₂ O) after the addition of water is introduced into the rectifying section 42 and uniformized in the y direction.

The plasma generating unit 60 is stored inside the ejection nozzle 40. The plasma generating unit 60 includes at least a pair of electrodes 61 and 61. These electrodes 61 and 61 extend in the y direction, respectively. A solid dielectric layer (not shown) is formed on the opposite surface of at least one electrode 61. A power supply (not shown) is connected to one electrode 61. The other electrode 61 is electrically grounded. An approximately atmospheric plasma discharge space 62 is created between the pair of electrodes 61. The discharge space 62 has a slit shape extending in the y direction like the electrode 61. In the discharge space 62, the source gas CF ₄ + Ar + H ₂ O is plasmalized (including decomposition, excitation, activation, radicalization, ionization, and the like). As a result, the source gas component is decomposed to generate a processing gas containing fluorine-based reaction components such as hydrogen fluoride (HF) and COF ₂ (Scheme 1). In the fluorine-based reaction component, COF ₂ is further reacted with water and converted to hydrogen fluoride (Scheme 3).

<Reaction Scheme 3>

In this embodiment to contribute to the substantially whole amount of H ₂ O in the raw material gas generation reaction of hydrogen fluoride (Scheme 1, Scheme 3), the amount of such water addition unit 12 is set. Accordingly, the H ₂ O content in the process gas is small enough to be substantially negligible in, or 0%.

In addition to the fluorine-based reaction component, the processing gas also includes undecomposed raw material gas components (CF ₄ , Ar, H ₂ O). This processing gas is taken out from the blowout port 41 upwards. The blowout flow of the processing gas is uniform in the y direction.

Although not shown, exhaust means such as a suction pump is connected to the suction nozzle 50. By driving the exhaust means, the gas in the processing space 23 is sucked into the suction port 51 of the suction nozzle 50 and exhausted. The exhaust flow rate from the suction nozzle 50 is larger than the supply flow rate of the processing gas from the ejection nozzle 40. Outside air (air and the like) corresponding to the difference between the exhaust flow rate and the supply flow rate flows into the processing unit internal space 29 from the inlet port 26 and the outlet port 27. Outside air from the inlet port 26 flows in through the outlet port 41 into the processing space 23. On the other hand, the outside air from the discharge port 27 is sucked into the suction port 51 and hardly reaches the processing space 23. Therefore, the processing atmosphere in the processing space 23 becomes a mixed gas of the inflow air from the inlet 26 and the processing gas. Hereinafter, "inflow outdoor air" shall refer to the outdoor air which flows into the processing space 23 from the said delivery opening 26 unless there is particular notice.

Normally, the incoming outside air contains moisture and the humidity is at least 0%. In this embodiment, the exhaust flow rate from the suction nozzle 50 is set to be sufficiently larger than the supply flow rate of the processing gas, and the flow rate of the inflow external air is set to be sufficiently larger than the supply flow rate of the processing gas (for example, about 10 times). Therefore, while the water content of the processing gas is very small, the steam partial pressure of the processing atmosphere in the processing space 23 is almost equal to the steam partial pressure of the outside air.

The conveying means 30 includes the roller shaft 31 and the conveying roller 32 formed in the lower part of the processing part 20. The plurality of roller shafts 31 are arranged in parallel at intervals in the x direction toward the width direction y, respectively. A plurality of conveying rollers 32 are formed at intervals in the axial direction y of each roller shaft 31. The upper end part of the conveyance roller 32 protrudes upward rather than the upper surface of the bottom plate 22 through the roller hole 25 of the bottom plate 22, and faces in the process space 23. As shown in FIG. The amount of projection from the upper surface of the bottom plate 22 of the conveying roller 32 corresponds to the distance (working distance WD) between the second surface 9b of the substrate 9 to be processed and the ejection opening 41. The working distance WD is, for example, about WD = 2 mm to 10 mm.

The conveying means 30 conveys in the direction of arrow a (left side in FIG. 1) along the x direction, supporting the to-be-processed substrate 9 horizontally. Thereby, the to-be-processed board | substrate 9 is let in in the process space 23 from the delivery opening 26, passes through the process space 23, and is carried out from the carrying out opening 27. As shown in FIG. As for the conveyance speed of the to-be-processed substrate 9 by the conveyance means 30, about 0.1 m / min-about 20 m / min are preferable. The conveying means 30 also serves as supporting means for supporting the substrate 9 to be processed and arranged in the processing space 23. The first surface 9a of the substrate 9 to be processed faces upward, and the second surface 9b faces downward.

The atmospheric pressure etching apparatus 1 is further equipped with the adjustment means. The adjusting means adjusts the temperature of the first surface 9a and the second surface 9b of the substrate 9 in relation to the condensation point of the mixed system of hydrogen fluoride and water in the processing space 23. In this embodiment, the upper plate 21 includes a plate heater as described above, and is provided as a main element of the adjusting means. The upper plate, i.e., the plate heater 21, is disposed on the side opposite to the ejection nozzle 40 with the position where the substrate 9 to be processed in the processing space 23 is arranged interposed therebetween. It is arranged. A top plate, that is, when the example the distance d ₁ of the first surface (9a) of the target substrate 9 is placed in the position for example, d ₁ = about 2 mm to 10 mm of the heater 21 is preferable. The heater 21 can be temperature-set in the range from room temperature to about 50 degreeC, for example. The set temperature of the heater 21 is set according to the humidity of the outside air and the partial pressure of steam in the processing atmosphere in the processing space 23, the process gas and the partial pressure of hydrogen fluoride in the processing atmosphere in the processing space 23.

The method of light-etching the to-be-processed substrate 9 by the atmospheric pressure etching apparatus 1 comprised as mentioned above is demonstrated.

A predetermined amount of water vapor (H ₂ O) is added to the raw material gas (CF ₄ + Ar) from the fluorine-based raw material supply unit 11 by the water addition unit 12 to obtain a humidified raw material gas. The humidifying raw material gas (CF ₄ + Ar + H ₂ O) is homogenized in the width direction y by the rectifying section 42 and then plasma-formed by the plasma generating section 60. This produces a processing gas containing at least hydrogen fluoride among hydrogen fluoride and water. By adjusting the amount of steam addition in the water addition unit 12, the hydrogen fluoride partial pressure and the steam partial pressure of the processing gas can be adjusted. Here, almost all of the moisture in the source gas is consumed for the production of hydrogen fluoride, and the partial pressure of steam of the processing gas is substantially zero. The temperature of the processing gas is around room temperature.

This processing gas is taken out from the outlet 41 and supplied into the processing space 23. In parallel, the gas in the processing space 23 is sucked by the suction nozzle 50 and exhausted. This exhaust flow rate is made larger than the processing gas supply flow rate. Therefore, much larger amount of outside air is wound into the processing space 23 than the processing gas and mixed with the processing gas. In addition, the partial pressure of steam in the processing atmosphere (the mixed gas of the processing gas and the inflowing outside air) in the processing space 23 is approximately equal to the partial pressure of steam in the outside air. The hydrogen fluoride partial pressure in the processing atmosphere is equal to the hydrogen fluoride partial pressure in the processing gas. The condensation point of hydrogen fluoride and water in the treatment atmosphere is determined in accordance with the hydrogen fluoride partial pressure and the steam partial pressure in the treatment atmosphere. That is, the critical temperature at which the condensation layer of hydrofluoric acid is produced is determined (FIG. 11).

The initial temperature of the to-be-processed substrate 9 is normally room temperature, or is about 15 to 35 degreeC. Here, the initial temperature of the to-be-processed substrate 9 means the temperature of the to-be-processed substrate 9 immediately before carrying in the to-be-processed substrate 9 in the process part 20. FIG. Usually, just before the said carry-in, the whole to-be-processed substrate 9 becomes the said initial temperature. Therefore, the 1st surface 9a and the 2nd surface 9b are said initial temperature. The substrate 9 is sent from the inlet 26 into the processing space 23, and the other end side from the one end side (right side in FIG. 1) of the processing space 23 along the direction of arrow a in FIG. 1. It conveys to (left side in FIG. 1). Then, the to-be-processed substrate 9 covers the upper side of the extraction nozzle 40, and the process gas taken out from the ejection opening 41 contacts the at least 2nd surface 9b of the to-be-processed substrate 9. FIG. In addition, a part of the processing gas diffused in the processing space 23 contacts the first surface 9a of the substrate 9 to be processed.

As described above, both the extraction temperature of the processing gas and the initial temperature of the substrate 9 are near room temperature, and the temperature difference between them is small. Therefore, the temperature of the to-be-processed substrate 9 hardly changes by spraying of process gas.

Prior to the carrying-in of the to-be-processed substrate 9, the upper plate, ie, the heater 21, is heated to a set temperature and kept at the set temperature. The set temperature of the heater 21 is set at a higher temperature than the condensation point of hydrogen fluoride and water in the processing atmosphere, and is preferably slightly above the condensation point. For example, the set temperature of the heater 21 is adjusted to be higher than 0 ° C. to 60 ° C. above the condensation point. The heat of this heater 21 is transmitted in a non-contact manner to the first surface 9a of the substrate 9 to be introduced into the processing space 23. Thereby, the 1st surface 9a can be heated to desired temperature. The desired temperature is higher than the condensation point, is approximately equal to or lower than the set temperature, for example, greater than 0 ° C. to 40 ° C. above the condensation point. By making the distance d ₁ between the heater 21 and the to-be-processed substrate 9 small, it is possible to reliably warm up (temperature control) the first surface 9a.

When the first surface 9a of the substrate 9 is warmed, the temperature of the second surface 9b is kept below the condensation point (for example, 0 ° C to 10 ° C lower than the condensation point) and Preferably, it is kept almost at said initial temperature. That is, the heat from the heater 21 is hardly transmitted to the second surface 9b of the substrate 9 to be processed. As described above, when the initial temperature difference between the condensation point and the processing target substrate 9 is made small and the first surface 9a of the processing target substrate 9 is heated a little, the set temperature higher than the condensation point is reached. By doing so, the amount of heat applied to the first surface 9a of the substrate 9 from the heater 21 can be reduced. As a result, the heat can be prevented or prevented from reaching the second surface 9b of the substrate 9.

The conveyance speed by the conveyance means 30 can also be adjusted so that the to-be-processed substrate 9 may be carried out from the process space 23 and the carrying out opening 27 before heat reaches the 2nd surface 9b. In this case, the conveying means 30 becomes an element of the "adjusting means" of a claim. The set temperature of the heater 21 is set in consideration of the conveyance speed. When the conveyance speed is relatively large, the set temperature of the heater 21 is sufficiently higher than the desired temperature of the first surface 9a. Thereby, the time required before the first surface 9a reaches the desired temperature can be shortened. On the other hand, by carrying out high speed conveyance, the to-be-processed substrate 9 can be carried out from the carrying out opening 27, even if the 2nd surface 9b does not become high temperature than a condensation point. On the other hand, when the conveyance speed is relatively small, the set temperature of the heater 21 can be made approximately equal to the desired temperature of the first surface 9a. Thereby, it can avoid that the to-be-processed board | substrate 9 becomes higher than said desired temperature. On the other hand, in the case of low-speed conveyance, although heating time becomes long, the temperature of the 2nd surface 9b can be kept below the said condensation point by setting a set temperature to just a high temperature rather than the said condensation point. For example, when the temperature of the processing gas is room temperature and the desired temperature of the first surface 9a is 40 ° C. to 50 ° C., the heater 21 at the time of high speed conveyance having a conveyance speed of about 5 mm / sec to 10 mm / sec. ) Is set to 10 to 20 degreeC higher than the desired temperature of the 1st surface 9a. On the other hand, at the time of low speed conveyance whose conveyance speed is about 1 mm / sec or less, the set temperature of the heater 21 is made to be substantially equal to the desired temperature of the 1st surface 9a.

Since the temperature of the 2nd surface 9b is below the said condensation point, when the hydrogen fluoride vapor and water vapor in a process atmosphere come into contact with the 2nd surface 9b, it will condense and the condensation layer of hydrofluoric acid will be formed. As a result, the silicon-containing water, the etching reaction of SiO ₂ etc. that make up the second side (9b) up, it is possible to blend the light second side (9b).

On the other hand, since the temperature of the first surface 9a of the substrate 9 to be processed is higher than the condensation point, no condensation occurs even if the hydrogen fluoride vapor and water vapor in the processing atmosphere come into contact with the first surface 9a. Therefore, the formation of the condensation layer on the first surface 9a can be prevented. As a result, etching of the 1st surface 9a can be prevented and the surface state of the 1st surface 9a can be kept favorable.

After the roughening process by the said atmospheric pressure etching apparatus 1, the to-be-processed substrate 9 is conveyed to another surface processing apparatus (not shown). The substrate 9 to be processed is placed on the stage of the surface treatment apparatus, and the second surface 9b is brought into contact with the stage and adsorbed. Since the roughness of the 2nd surface 9b is small, the to-be-processed substrate 9 can be reliably attracted to a stage, and can be maintained. Moreover, surface treatment, such as washing | cleaning, surface modification, etching, ashing, and film-forming, is performed to the 1st surface 9a. Since the 1st surface 9a avoids roughening by the above-mentioned roughening process, favorable surface treatment can be performed. Furthermore, the quality of various electronic element layers, such as an insulating layer, a conductive layer, and a semiconductor layer formed by the said surface treatment, can be made favorable. After the surface treatment of the first surface 9a, the substrate 9 to be processed is taken out from the stage. Since the minute unevenness | corrugation is formed in the 2nd surface 9b by the said roughening process, the to-be-processed substrate 9 can be easily isolate | separated from a stage. As a result, it is possible to prevent the substrate 9 to be bent or broken.

Next, another embodiment of the present invention will be described. In the following embodiment, about the part which overlaps with the form mentioned above, the same code | symbol is attached | subjected to drawing, and description is abbreviate | omitted suitably.

As shown in FIG. 3 and FIG. 4, the atmospheric pressure etching apparatus 1A of 2nd Embodiment is a conveyance means 30 of the to-be-processed substrate 9, the roller conveyor 33 for carrying in, and the roller conveyor for processing ( 34) and a roller conveyor 35 for carrying out are provided. Each roller conveyor 33, 34, 35 has the several roller shaft 31 arranged in the x direction (left-right direction of FIG. 3), and the conveyance roller 32 formed in each roller shaft 31. As shown in FIG. The roller conveyor 33 for carrying in is arrange | positioned at the one end side (right side in FIG. 3) of an x direction rather than the process part 20, and carries in the to-be-processed board | substrate 9 to the process space 23. FIG. The roller conveyor 34 for a process is formed in the lower part of the bottom plate 22, and conveys the to-be-processed substrate 9 in the process space 23. As shown in FIG. The roller conveyor 35 for carrying out is arrange | positioned rather than the process part 20 at the other end side (left side in FIG. 3) of an x direction, and carries out the to-be-processed substrate 9 from the process space 23. As shown in FIG.

In the lower part of the bottom plate 22, a plurality of covers 70 for the processing roller conveyor 34 are formed. The cover 70 corresponds one-to-one with the roller shaft 31 of the processing roller conveyor 34. The cover 70 has a container shape that extends in the axial direction y of the roller shaft 31. The corresponding roller shaft 31 and the conveyance roller 32 are accommodated in each cover 70. The upper surface of the cover 70 is opened and abuts against the lower surface of the bottom plate 22.

The cover 70 may be comprised with metals, such as aluminum, and may be comprised with resins, such as vinyl chloride. On the inner surface of the cover 70, a resin film having high fluorine resistance and plasma resistance such as polytetrafluoroethylene may be formed.

As shown in FIG. 4, the roller shaft 31 of the processing roller conveyor 34 penetrates the end wall 74 of the both sides of the cover 70 in the longitudinal direction. The end wall 74 is formed with the airtight bearing 75. The roller shaft 31 is rotatably supported by the hermetic bearing 75. In addition, between the roller shaft 31 and the end wall 74 is hermetically sealed by the hermetic bearing 75. It is preferable that the structural member of the hermetic bearing 75 is made of resin having high fluorine resistance and plasma resistance, such as polytetrafluoroethylene.

The inside of the cover 70 communicates only with the processing space 23 through the roller hole 25.

According to the second embodiment, it is possible to prevent the outside air (air or the like) under the atmospheric pressure etching apparatus 1A from being drawn into the processing space 23 through the roller hole 25. In addition, when the processing gas of the processing space 23 leaks to the lower side of the bottom plate 22 through the roller hole 25, the processing gas can be trapped inside the cover 70. Thus, leakage of the processing gas to the outside can be prevented.

The suction nozzle 50 of 2nd Embodiment is arrange | positioned at the intermediate part of the bottom plate 22 in the x direction. The upper plate 21 and the bottom plate 22 extend from the suction nozzle 50 to the other end side in the x direction (left side in FIG. 3), that is, the downstream side in the conveying direction of the substrate 9. Only a portion corresponding to the ejection nozzle 40 and the suction nozzle 50 in the upper plate 21 may be kept warm at a set temperature as an adjusting means, and the entire area of the upper plate 21 is used as an adjusting means. It may be kept to a set temperature.

5 and 6 show a third embodiment of the present invention. The atmospheric pressure etching apparatus 1B of this embodiment does not have the bottom plate 22. The processing space 23 is partitioned by the entire upper surface of the ejection nozzle 40 and the lower surface of the upper plate 21. Within the treatment space 23 is a treatment atmosphere comprising HF steam and water vapor. By adjusting the length of the ejection nozzle 40 in the x direction, the length of the processing space 23 can be adjusted, and further, the processing time for the substrate 9 to be in contact with the processing atmosphere can be increased or decreased. As a result, it can adjust so that the etching amount of the 2nd surface 9b may become a desired amount.

As shown in FIG. 5, the atmospheric pressure etching apparatus 1B is provided with a gas suction system 80. The gas suction system 80 includes a suction pump 81 and a pair of leaflets 82 and 84. The pair of leaflets 82 and 84 are disposed vertically on both sides in the x direction with the extraction nozzle 40 interposed therebetween. The upper ends of the leaflets 82 and 84 are aligned so as to be flush with the upper surface of the ejection nozzle 40. The thickness of the leaflets 82, 84 is, for example, about several mm to several tens of mm, and here about 5 mm.

As shown in FIG. 6, the leaflet 82 on the carry-in side (right side in the drawing) extends in the y-direction orthogonal to the x-direction along the outer surface of the carry-in nozzle 40 on the carry-in side. As shown in FIG. 5 and FIG. 6, the suction path 83 is partitioned between the leaflet 82 and the outer surface of the taking-out nozzle 40 at the carrying-in side. The lower end part of the suction path 83 is connected to the suction pump 81. The upper end part (suction port) of the suction path 83 is connected to the edge part at the carrying in side of the processing space 23. The opening width in the x direction of the suction port 83 of the suction passage 83 is, for example, about several mm to several tens of mm, and here about 10 mm.

The carry-in port 26 is arrange | positioned in the vicinity of the suction port of the suction path 83. As shown in FIG. The carry-in port 26 is partitioned by the upper end part of the leaflet 82 and the edge part at the carrying-in side of the upper plate 21. The delivery port 26 is connected to the end of the carry-in side of the processing space 23, and is connected to the suction path 83.

As shown in FIG. 6, the leaflet 84 on the carrying out side (left side in the drawing) extends in the y direction along the outer surface of the carrying out nozzle 40 on the carrying out side. As shown in FIG. 5 and FIG. 6, a suction path 85 is partitioned between the leaflet 84 and the outer surface of the ejection side of the ejection nozzle 40. The lower end part of the suction path 85 is connected to the suction pump 81. The upper end part (suction port) of the suction path 85 is connected to the edge part at the carrying out side of the process space 23. The opening width in the x direction of the suction port of the suction passage 85 is, for example, about several mm to several tens of mm, and here about 10 mm.

The discharge port 27 is arranged in the vicinity of the suction port of the suction path 85. The carry-out port 27 is partitioned by the upper end part of the leaflet 84 and the edge part at the carrying-out side of the upper plate 21. The discharge port 27 is connected to the end of the carry-out side of the processing space 23 and is connected to the suction path 85.

As shown in FIG. 6, the end wall 86 is formed in the both ends of the width direction y of the process part 20, respectively. Both end portions in the width direction y of the suction passages 83 and 85 are blocked by the end walls 86.

In the atmospheric pressure etching apparatus 1B of the third embodiment, when light etching the second surface 9b of the substrate 9 to be processed, the processing gas g1 that has been converted into plasma is removed from the outlet 41 by the processing space 23. Take out. In parallel with this, the suction pump 81 of the gas suction system 80 is driven to perform gas suction from the suction paths 83 and 85. As shown in FIG. 7A, in the state where the substrate 9 to be processed is not introduced into the processing space 23, the processing gas g1 is formed at the outlet 41 in the processing space 23. In the upper part, there is separated into a flow toward the import side (right side in the drawing) and a flow toward the export side (left side in the drawing). The processing gas directed to the carry-in side is sucked into the suction path 83 from the end of the carry-in side of the process space 23. The processing gas directed to the carry-out side is sucked into the suction path 85 from the end of the carry-out side of the process space 23.

In addition, the outside air enters the inlet port 26 by the gas suction of the gas suction system 80. This outside air is sucked into the suction path 83 from the delivery opening 26. Similarly, outside air also enters the discharge opening 27. This outside air is sucked into the suction path 85 from the discharge port 27. Therefore, the outside air hardly flows into the processing space 23 between the upper surface of the blowout nozzle 40 and the upper plate 21. Therefore, the gas composition of the processing atmosphere in the processing space 23 is approximately equal to the composition of the processing gas itself after the plasma formation. That is, the HF partial pressure and the steam partial pressure in the processing space 23 are approximately equal to the HF partial pressure and the steam partial pressure of the processing gas itself. Therefore, even if the humidity, temperature and the like of the outside air change, the HF partial pressure and the steam partial pressure in the processing space 23 hardly change.

As shown in FIG. 7B, when the end portion of the processing target substrate 9 is carried into the carry-in port 26, the opening area of the carry-in port 26 is narrowed to increase the flow resistance, thereby bringing in the carry-in port 26. Flow rate of the outside air (g2) flowing from the () decreases or the flow rate increases. The inflowing outside air g2 includes the outside air g2a passing above the substrate 9 and the outside air g2b passing below the second surface 9b. Among them, the lower inflow external air g2b is sucked into the suction path 83 immediately from the delivery port 26. Therefore, the inflow external air g2b of the lower side hardly enters the process space 23.

The upper inflow outside air g2a returns to the lower side along the end face of the substrate 9 to be sucked into the suction path 83 in a state where the end portion of the substrate 9 is located at the carrying inlet 26. do. Therefore, even in the upper inflow external air g2a, it hardly enters into the process space 23. FIG. Therefore, even if the flow rate and the flow rate of the inflow external air g2 change when the end of the substrate 9 to be carried in from the inlet port 26, the gas composition in the processing space 23 can be suppressed or prevented from changing. have.

As shown in FIG. 7C, the substrate 9 to be treated covers the suction path 83. In this state, the suction force of the gas suction system 80 does not act so much on the portion of the processing space 23 above the substrate 9 (hereinafter referred to as the "first processing space portion 23a"). Thus, the suction flow rate of the outside air g2a is reduced. The upper outside air g2a can flow into the inlet 26 by being viscous with the upper surface of the substrate 9 to be processed, but the inflow amount thereof can be sucked into the suction system 80 (Fig. 7 (a) It is small enough compared with) to (b)). Therefore, the processing atmosphere between the upper plate 21 and the substrate 9 to be processed is maintained at a gas composition almost identical to that of the processing gas itself.

The inflow amount of outside air g2b from the lower side of the to-be-processed substrate 9 becomes large so that the inflow amount of the outside air g2a of the upper side may fall. Even if the flow rate increases, almost all of the inlet outdoor air g2b is immediately sucked into the suction path 83. Therefore, the outside air g2b rarely enters the processing space 23, and the processing space between the processing target substrate 9 and the extraction nozzle 40 (hereinafter referred to as "second processing space portion 23b") The processing atmosphere of is maintained at almost the same gas composition as the processing gas itself.

The fluctuation of the inflow of outside air as described above occurs similarly when the substrate 9 to be processed is taken out of the processing space 23. In this case, the flow rate and flow rate of the outside air flowing in from the discharge port 25 fluctuate. Almost all of the inflowing outdoor air from this discharge port 25 is sucked into the suction path 85. Therefore, even at the time of carrying out, the gas composition in the processing space 23 is kept substantially constant irrespective of fluctuations in the flow rate and the flow rate of the inflowing outside air.

In this manner, in the etching apparatus 1B, the flow rate and flow rate of the outdoor air g2 flowing into the processing space 23 through the inlet 26 and the outlet port 27 are applied to the carrying in and the carrying out of the substrate 9 to be processed. Even if it fluctuates accordingly, the gas composition of the process atmosphere in the process space 23, and HF partial pressure and water vapor partial pressure can be kept substantially the same as that of the process gas itself, respectively. As a result, the etching process of the 2nd surface 9b can be prevented from becoming nonuniform. In addition, it is possible to prevent the humidity in the processing atmosphere between the upper plate 21 and the substrate to be processed 9 from rising, and to prevent the formation of a condensation layer on the first surface 9a. Therefore, etching to even the 1st surface 9a can be avoided. Even when the humidity of the outside air is quite high with respect to the humidity of the processing atmosphere in the processing gas 23 and the processing space 23, it is possible to reliably prevent the formation of a condensation layer on the first surface 9a, and thus, the first surface 9a. Can be reliably avoided to be etched.

In addition, as will be described later, in the state of FIG. 7C, even when the external air g2a is wound into the first processing space part 23a, the second surface 9b is controlled by controlling the amount of this winding. Only harmony is possible.

This invention is not limited to the said embodiment, A various change can be made in the range which does not deviate from the meaning.

For example, in the said embodiment, although the 1st surface 9a was a main surface which should form an electronic element, and the 2nd surface 9b which should be roughened (etched) was a back surface, the 1st surface 9a was a back surface and roughening ( The second surface 9a to be etched may be the main surface to form the electronic element. Both of the first and second surfaces may be surfaces on which electronic elements are formed. The substrate to be processed is not limited to glass, and may be a semiconductor wafer or the like. In addition, the to-be-processed substrate is not limited to the board | substrate with which an electronic element is formed, or the board | substrate for semiconductor devices.

The silicon-containing object to be etched is not limited to SiO ₂ , and may be SiN, Si, SiC, SiOC, or the like.

The film | membrane containing a silicon-containing substance may be formed in the to-be-processed substrate 9, and the apparatus of this invention 1 may etch the said film | membrane.

The temperature control means of the 1st surface 9a and the 2nd surface 9b of the to-be-processed substrate 9 may be electrothermal heaters other than a plate heater, a heating medium heater, or a radiant heater. As the heating medium heater, for example, the upper plate 21 may have a heating medium flow path through which a heating medium such as temperature-controlled water passes, or a storage chamber for storing the heating medium. The temperature may be adjusted by heating the heating medium stored in the storage chamber. Also in 1st Embodiment, the whole area | region of the upper plate 21 may be made to adjust temperature, and a part (for example, center part, one end part, etc.) of the upper plate 21 may be made to partially adjust temperature. The temperature regulating means (heater) may be formed separately from the upper plate 21, and the temperature regulating means (heater) heats the upper plate 21 and the substrate to be processed 9 through the upper plate 21. It is also possible to warm the first surface 9a of the.

The second surface 9b of the substrate to be processed can be cooled, whereby the temperature of the second surface 9b can be adjusted so that the desired temperature is lower than the condensation point. For example, the 2nd surface 9b of the to-be-processed substrate can also be cooled by forming the media flow path which lets a cooling medium, such as cold water, pass through the bottom board 22, and cooling the bottom board 22. FIG. In this case, the said cooling means of the 2nd surface 9b becomes an element of the "adjusting means" of a claim. It is preferable to adjust the temperature of the second surface 9b to be 0 ° C to 10 ° C lower than the condensation point by the cooling means.

It is also possible to adjust the humidity around the apparatus 1 and further to adjust the partial pressure of water vapor in the processing atmosphere. In this case, the humidity control means around the apparatus 1 becomes an element of the "regulation means" of the claims.

The processing gas may contain some moisture. The partial pressure of water vapor in the processing atmosphere may be largely dependent on the amount of water added by the water addition unit 12. In this case, the water addition part 12 becomes an element of the "adjustment means" of a claim.

The plasma generating unit 60 may be formed outside the extraction nozzle 40 or may be formed away from the extraction nozzle 40. The plasma generating unit 60 may cause the raw material gas to be plasma to generate a processing gas, and then the processing gas may be transported to the ejection nozzle 40.

The processing gas is not limited to being formed by plasmaation. For example, a tank containing an aqueous hydrogen fluoride solution may be prepared as a processing gas source, and the aqueous hydrogen fluoride solution may be vaporized to be transported to the ejection nozzle 40.

The processing gas may contain an oxidizing component such as ozone. Ozone can be generated by an ozone generator or an oxygen plasma generating device.

The attitude | position of the to-be-processed board | substrate 9 is not limited to a horizontal but may be perpendicular, and may be inclined with respect to a horizontal or vertical.

The second surface of the substrate 9 to be processed may face upward, and the first surface may face downward. The temperature adjusting means (heater) is disposed below the substrate 9, the extraction nozzle 40 is disposed above the substrate 9, and the processing gas is removed from the upper side of the substrate 9. It is also possible to spray the processing substrate 9.

The to-be-processed substrate 9 is not limited to one-way movement in the direction of the arrow a of the x direction, but can also be made to reciprocate in the process space 23.

Support means for supporting the substrate 9 to be processed may be formed separately from the conveying means 30. The position of the to-be-processed substrate 9 can be fixed by a support means, and the process part 20 can be moved by a conveyance means. It is not limited to performing an etching process, moving the to-be-processed board | substrate 9 and the process part 20 relative to each other, You may make it perform an etching process in the state which fixed the relative position of the to-be-processed substrate 9 and the process part 20. have.

&Lt; Example 1 >

An Example is described. It goes without saying that the present invention is not limited to the following examples.

In Example 1, the atmospheric pressure etching apparatus 1 substantially the same as FIG. 1 and FIG. 2 was used.

SiN (silicon containing material) was formed on the 1st surface 9a and the 2nd surface 9b using the glass substrate as the to-be-processed substrate 9, respectively.

The dimension of the to-be-processed substrate 9 was as follows.

Length along the x direction: 670 mm

Width in the y direction: 550 mm

Thickness: 0.7 mm

The dimensional structure of the atmospheric pressure etching apparatus 1 was as follows.

Length along x direction of bottom plate 22: 0.3 m

Thickness in the vertical direction of treatment space 23: d ₀ = 8 mm

Width in the y direction of the processing space 23: 600 mm

Working distance: WD = 4 mm

The upper plate, that is, the distance between the lower surface of the plate heater 21 and the upper surface of the substrate 9 to be processed: d ₁ = 4 mm

The composition of source gas was as follows.

Ar: 8.7 slm

CF ₄ : 0.3 slm

H ₂ O: 0.19 sccm

The source gas was converted into plasma by the rectifier 42 to generate a process gas. Therefore, the flow volume of the processing gas was 9 sccm steel.

Plasma generation conditions were as follows.

Interelectrode Spacing: 1 mm

Interelectrode Voltage: Vpp = 12.8 kV

Frequency of voltage between electrodes: 25 kHz (pulse wave)

Supply power: DC voltage before pulse conversion = 370 V, current = 9.4 A

The displacement from the suction port 51 was 500 slm. As a result, the outside air introduced into the processing space 23 from the delivery port 26 was about 120 slm.

Process gas Furthermore, the hydrogen fluoride partial pressure of the process atmosphere in the process space 23 was 6.2 Torr.

The atmosphere around the apparatus was atmospheric pressure, the temperature (room temperature) around the apparatus was 25 ° C, and the relative humidity was about 30%. As shown in FIG. 11, the partial pressure of steam corresponding to this relative humidity is 7.1 Torr. In addition, the condensation point of hydrogen fluoride and water in this processing atmosphere is about 27 degreeC.

The initial temperature before carrying in into the process space 23 of the to-be-processed substrate 9 was 25 degreeC.

The substrate 9 to be processed was conveyed in the direction of an arrow a in the x direction and passed through the processing space 23. The number of times (number of scans) that passed the substrate 9 to be processed into the processing space 23 was one time.

The conveyance speed of the to-be-processed substrate 9 was 4 m / min.

Extraction of the processing gas from the ejection nozzle 40 starts before the substrate 9 is carried into the processing space 23, and continues until the substrate 9 is carried out from the processing space 23. It was done.

The upper plate, that is, the plate heater 21 was kept at a set temperature, and furthermore, the temperature of the first surface 9a was adjusted. The set temperatures of the heater 21 were four types of 25 degreeC, 30 degreeC, 35 degreeC, and 45 degreeC.

At 25 ° C., condensation formed on the lower surface of the upper plate 21. At 30 degreeC, 35 degreeC, and 45 degreeC, condensation did not form in the lower surface of the upper plate 21. In addition, when the upper plate 21 was heated from 25 ° C, condensation was lost at 27 ° C to 28 ° C.

The etching rate of the SiN film on the 1st surface 9a and the SiN film on the 2nd surface 9b was measured about the to-be-processed substrate 9 after a process. The measurement position was set at every 1 mm interval in the width direction y at the center part of the x direction of each surface 9a, 9b of the to-be-processed substrate 9. The etching depth was divided by the number of scans for each measurement position, and the etching amount (nm / scan) per scan (one-way transfer) was obtained. Moreover, the average value of the etching rate of each said measurement position in each surface 9a, 9b was calculated | required.

8 shows the average etch rate. As shown in the figure, when the heater set temperature was 25 ° C, not only the SiN film on the second surface 9b but also the SiN film on the first surface 9a were etched to the same extent as the second surface 9b. .

When the heater set temperature was 30 ° C., a sufficient etching amount could be obtained for the SiN film on the second surface 9b, whereas the etching amount of the SiN film on the first surface 9a was very small and the SiN film was hardly etched. Confirmed.

Even when the heater set temperatures were 35 ° C and 45 ° C, a sufficient etching amount was obtained for the SiN film on the second surface 9b as in the case of 30 ° C, whereas the SiN film on the first surface 9a was almost etched. It wasn't.

From the above result, the temperature of the 1st surface 9a is made higher than the condensation point of hydrogen fluoride and water in a process atmosphere, and the temperature of the 2nd surface 9b is lower than the said condensation point, and it is the 1st surface 9a. It was confirmed that the 2nd surface 9b can be etched, suppressing or preventing that is etched.

9 and 10 are etching rates at the respective measurement positions of the respective surfaces 9a and 9b, and show distributions of the etching rates in the width direction y. As shown in FIG. 9A, when the heater set temperature was 25 ° C., the etching rate varied greatly depending on the position of the width direction y on both the first surface 9a and the second surface 9b. As a factor of nonuniformity, the influence of the conveyance roller 33 is also considered. The disposition position of the conveyance roller 33 was each position of -35 mm, 0 mm, and 35 mm in the horizontal axis of FIG. 9 and FIG.

On the other hand, as shown in FIG. 9B, when the heater set temperature was 30 degreeC, the etching rate became almost uniform on the 1st surface 9a and the 2nd surface 9b.

As shown in FIG. 10A and FIG. 10B, when the heater set temperature was 35 degreeC and 45 degreeC, the etching rate became substantially uniform on the 1st surface 9a and the 2nd surface 9b similarly to the case where it was 30 degreeC.

From the above result, by making the 1st surface 9a higher than the condensation point of hydrogen fluoride and water in a process atmosphere, not only etching of the 1st surface 9a is suppressed but 1st surface 9a and 2nd surface ( It turned out that the uniformity of the etching of 9b) becomes high.

Further, on the basis of vapor-liquid equilibrium curve of the HF aqueous solution, 11, it is calculated according to the condensing temperature of the HF-H ₂ O system was graphed. Horizontal dashed lines in the graph indicate relative humidity (% RH) and correspond to the H ₂ O partial pressure in the processing atmosphere. In the graph, point A corresponding to the H ₂ O partial pressure (7.1 Torr (30% relative humidity)) and HF partial pressure (6.2 Torr) of the processing atmosphere of Example 1 is located on the gas phase side for the gas-liquid equilibrium curve of 25 ° C. The gas-liquid equilibrium curve of 30 ° C. or higher is located on the liquid phase side. Therefore, it was confirmed that the result of Example 1 is consistent with theoretical calculation data. Therefore, when setting the processing conditions, using the graph illustrated in FIG. 11, the points on the graph corresponding to the HF partial pressure and the H ₂ O partial pressure in the processing atmosphere correspond to room temperature or the initial liquid temperature of the substrate 9 to be processed. The heater set temperature and the process gas recipe (flow rate of the raw material gas component, the amount of steam addition, etc.) may be set so as to be located on the gaseous side rather than the curve and on the liquid side rather than the gas-liquid equilibrium curve corresponding to the heater set temperature.

12 is a graph of condensation conditions of the HF-H ₂ O system in the etching apparatus 1B of the third embodiment (FIGS. 5 to 7). In the etching apparatus 1B, since almost no outside air enters into the processing space 23, the gas composition of the processing atmosphere is almost the same as the gas composition of the processing gas after plasma formation. The partial pressure of H ₂ O of the fluorine-based source gas after humidification, that is, the processing gas (CF ₄ + Ar + H ₂ O) before plasma formation is, for example, 10.8 Torr (dotted dashed line L1 in FIG. 12). Water in this processing gas is decomposed by plasmaation. Therefore, the H ₂ O partial pressure of the processing gas after plasma forming is lower than before plasma forming, for example, to 8.1 Torr (dashed line L2 in FIG. 12). In addition, HF partial pressure of the processing gas after plasma-forming is 4.2 Torr (broken line L3 of FIG. 12), for example. The intersection B of the broken line L2 and the broken line L3 represents the HF and H ₂ O partial pressures of the processing gas after plasma formation, and further, the HF and H ₂ O partial pressures of the processing atmosphere in the processing space 23. Therefore, if the temperature of the 2nd surface 9b of the to-be-processed board | substrate 9 is about 25 degreeC which is below the temperature of the point B, for example, the condensation layer of hydrofluoric acid will be formed on the 2nd surface 9b, thereby The second surface 9b can be etched reliably. Moreover, when the temperature of the 1st surface 9a of the to-be-processed substrate 9 of the to-be-processed board | substrate 9 is heated so that it may become about 30 degreeC higher than point B, for example by the heater 21, a condensation layer will be made to the 1st surface 9a. Formation can be avoided, and the 1st surface 9a can be reliably prevented from etching.

Further, even if the temperature of the first surface 9a of the substrate 9 to be processed is not made higher than the point B by the heater 21, the first surface 9a can be prevented from being etched. The case where the gas composition of the processing atmosphere shown by the point B of FIG. 12 mentioned above and the temperature of a processing atmosphere is 25 degreeC is demonstrated as an example.

In 3rd Embodiment shown in FIG. 5, the distance of the lower surface of the heater 21 and the 1st surface 9a of the to-be-processed substrate 9 is extended. The atmosphere of the processing space 23 is a condition indicated by the point B, but the outside air is wound up by the processing target substrate 9 entering the processing space 23 from the delivery port 26. By the way, the 2nd process space part 23b between the 2nd surface 9b and the upper surface of the extraction nozzle 40 by the process gas taken out and the exhaust gas just before the process space from the suction path 83 of the loading side. ) Does not enter the outside air. On the other hand, outside air enters into the first processing space portion 23a between the first surface 9a and the heater 21. Then, HF partial pressure of the 1st process space part 23a falls, and the partial pressure composition of a process atmosphere changes from the point B to the gaseous-phase side over a 25 degreeC gas-liquid equilibrium curve. Therefore, no condensation layer is formed on the first surface 9a, and the first surface 9a is not etched.

Thus, the distance of the lower surface of the heater 21 and the 1st surface 9a of the to-be-processed substrate 9 is adjusted suitably, and the winding of the outside air to the 1st process space part 23a by the to-be-processed substrate 9 is carried out. By controlling the amount of intake, only the second surface 9b can be matched without heating to the heater 21. At this time, it is preferable that the outside air is lower than the processing gas.

The present invention can be applied, for example, to the manufacture of semiconductor devices such as flat panel displays.

1, 1A, 1B: atmospheric pressure etching apparatus
9: substrate to be processed
9a: page 1
9b: page 2
10: raw gas supply means
11: Fluorine raw material supply part
12: water addition portion
20:
21: top plate, plate heater (adjustment means)
22: bottom plate
23: processing space
24: sidewall
25: roller hole
26: carry-on
27: exit
29: space in the processing unit
30: conveying means
31: roller shaft
32: conveying roller
33: Carrying roller conveyor
34: Roller Conveyor for Processing
35: roller conveyor for carrying out
40: ejection nozzle
41: outlet
42: rectifier
50: suction nozzle
51: inlet
60: plasma generating unit
61: electrode
62: discharge space
70: cover
74: end wall
75: hermetic bearing
80: gas aspiration system
81: suction pump
82: leaflet on the import side
83: suction path on the import side
84: leaflet on the export side
85: suction path on the discharge side
86: end wall

Claims (7)

A method of etching a substrate to be processed comprising a silicon content and having a first surface and a second surface that is a back surface of the first surface under a pressure of 1.013 × 10 ⁴ to 50.663 × 10 ⁴ Pa,
Placing the substrate to be treated in a processing atmosphere containing hydrogen fluoride vapor and water vapor;
And the temperature of the first surface is adjusted to be higher than the condensation point of hydrogen fluoride and water in the processing atmosphere, and the temperature of the second surface is below the condensation point. The etching method according to claim 1, wherein the temperature of the first surface is higher than 0 ° C to 40 ° C higher than the condensation point. The etching method according to claim 1, wherein the temperature of the second surface is set to 0 ° C to 10 ° C lower than the condensation point. The carry-out board according to any one of claims 1 to 3, wherein the substrate to be processed is loaded into the processing space from an inlet that is continuous in the processing space in which the processing atmosphere is present. And the substrate to be processed is taken out, and the gas is sucked in the vicinity of the delivery port and in the vicinity of the delivery port. Etching a substrate to be processed comprising a silicon content and having a first side and a second side being the back side of the first side in a processing space of 1.013 × 10 ⁴ to 50.663 × 10 ⁴ Pa at a pressure and humidity of more than 0%. As a device to
A extraction nozzle for supplying a processing gas containing at least hydrogen fluoride of hydrogen fluoride and water into the processing space to contact at least the second surface of the substrate to be processed;
And an adjusting means for adjusting the temperature of the first surface to be higher than the condensation point of hydrogen fluoride and water in the processing space and the temperature of the second surface to be below the condensation point. . The heater according to claim 5, wherein the adjustment means includes a heater disposed close to the position on the opposite side to the ejection nozzle with the position where the substrate to be processed is disposed in the processing space interposed therebetween. Etching apparatus, characterized in that the temperature is higher than 0 ℃ to 60 ℃ higher than the condensation point. The etching apparatus according to claim 5 or 6, wherein the adjusting means sets the temperature of the second surface to be 0 ° C to 10 ° C lower than the condensation point.

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