JP2008010727A - Device and method for vapor processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor processing device and a vapor processing method for carrying out vapor process of polysilicon TFT, SiO<SB>2</SB>gate insulating film and the like easily under high pressure. <P>SOLUTION: The vapor processing device is provided with a pressure container 11 for processing a processing material 21 under predetermined pressure P, and a temperature control means 12 for separating the inside of the pressure container 11 under control into at lest two different temperature regions. The pressure container 11 has a first region 13 set at a predetermined temperature T1 for processing the processing material 21 under predetermined vapor pressure P, and a second region 14 set at a predetermined temperature T2 lower than that of the first region 13 for generating saturation vapor under pressure P equal to the vapor pressure P so that the above mentioned subject is solved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a steam processing apparatus and a steam processing method for performing steam processing or the like on a polysilicon film constituting a polysilicon TFT used in a liquid crystal display, an SiO ₂ gate insulating film constituting a MOSFET, or the like under a predetermined pressure.

  Polysilicon thin film transistors (hereinafter referred to as polysilicon TFTs) are widely used as switching elements or circuit elements constituting active matrix drive type liquid crystal displays, organic EL displays, and the like. Also, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) are semiconductor elements having good semiconductor characteristics, and are therefore widely used as elements constituting electronic devices.

In order to further improve the switching characteristics of these polysilicon TFTs and the semiconductor characteristics of the MOSFET, it is possible to heat-treat the polysilicon film constituting the polysilicon TFT and the SiO ₂ gate insulating film constituting the MOSFET in a high-pressure steam atmosphere. It has been proposed (see, for example, Patent Documents 1 and 2). The heat treatment of a general semiconductor thin film is about 800 ° C. to 1000 ° C., and even the annealing treatment is about 400 ° C., whereas the heat treatment in a high-pressure steam atmosphere proposed in Patent Documents 1 and 2 is, for example, 5 In recent years, there has been an advantage that it can be processed at a low temperature of about 150 ° C. to 250 ° C. under a saturated vapor pressure of about 40 to 40 atm.

As shown in FIG. 4A, the heat treatment under such a high-pressure steam atmosphere is performed by placing water 102 and a device 103 having a polysilicon film or a SiO ₂ gate insulating film in a pressure vessel 101 and then applying pressure. When the temperature in the container 101 is raised by the heating device 104, the water 102 becomes steam and the pressure rises. The pressure in the pressure vessel 101 increases as the temperature in the pressure vessel 101 is increased based on the saturated vapor pressure curve of the water 102. For example, the pressure in the pressure vessel 101 increases to 5 atm at 150 ° C, 13 atm at 200 ° C, and about 40 atm at 250 ° C. If the temperature is further increased, the pressure can be further increased.
JP-A-8-55858 Japanese Patent Laid-Open No. 11-97438

In the processing apparatus 100 shown in FIG. 4A, the temperature in the pressure vessel 101 is raised to a high pressure by using the saturated vapor pressure. However, in the heat treatment of the polysilicon film or the SiO ₂ gate insulating film, about 250 ° C. If the temperature is desired to be processed, the pressure reaches 40 atm. For this reason, there is a problem that the pressure vessel 101 that can withstand a predetermined pressure must be employed even when the semiconductor device is processed at a relatively low temperature (for example, about 250 ° C.).

On the other hand, according to the study of the present inventor, the water vapor treatment of the polysilicon film or the SiO ₂ gate insulating film does not need to be so high if the heat treatment can be performed at a temperature of about 250 ° C., for example. It has been found that the atmosphere (250 ° C. and pressure of about 40 atm) is not required, and about 10 atm. Therefore, as shown in FIG. 4B, the present inventor puts a small amount of water 102 in the pressure vessel 101 at a pressure of about 10 atm, which is smaller than the saturated vapor pressure (about 40 atm) at 250 ° C., for example. Then, the temperature in the pressure vessel 101 was raised to 250 ° C. by the heating device 104 to vaporize all of the water 102, thereby attempting a steam treatment in an atmosphere of about 250 ° C. and 10 atm. However, in this method, since the amount of water directly regulates the pressure, there is a complication such as taking into account the volume of the pressure vessel and having to accurately measure the amount of water introduced into the interior.

  Further, it is possible to actively control the pressure while monitoring the pressure in the pressure vessel, but there is also a problem that the control mechanism is complicated.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a steam processing apparatus and a steam processing capable of easily steam-processing a polysilicon film, a SiO ₂ gate insulating film, and the like under high pressure. It is to provide a method.

  In order to solve the above problems, a steam processing apparatus of the present invention includes a pressure vessel for processing an object to be processed at a predetermined pressure, and a temperature for controlling the inside of the pressure vessel to at least two temperature regions having different temperatures. A steam processing apparatus including a control unit, wherein the pressure vessel is set to a predetermined temperature and is lower than the first region for processing the workpiece under a predetermined steam pressure. And a second region for generating saturated vapor under the same pressure as the vapor pressure.

  According to the present invention, first, a liquefied product (for example, water) is charged into the second region, and the second region is heated to a temperature at which the liquefied product evaporates to a predetermined saturated vapor pressure. Since the first region is in the same pressure vessel as the second region, the pressure is the same as the saturated vapor pressure, and if the temperature of the first region is set higher than the temperature of the second region, In one region, steam treatment can be performed at a desired high temperature condition under a pressure considerably lower than the virtual value of the saturated vapor pressure at the set temperature in the first region.

  Therefore, the first region constituting the steam processing apparatus of the present invention is set to a predetermined temperature and acts as a region for processing the object to be processed under a predetermined vapor pressure, and the second region is the first region. The temperature is set to a lower temperature and acts as a region for generating saturated steam under the same pressure as the steam pressure. Therefore, as shown in FIG. Even when processing at a temperature of about 0 ° C., the problem that a pressure vessel that can withstand a predetermined pressure (for example, about 40 atmospheres) must be adopted can be solved. Further, as shown in FIG. 4B, which is a conventional example, it is possible to eliminate the trouble of accurately measuring the amount of water to be introduced into the interior, and to monitor the pressure in the pressure vessel while monitoring the pressure in the pressure vessel. A complicated control mechanism for performing active control is also unnecessary.

  In the steam treatment apparatus of the present invention, the temperature control means includes a first temperature control device that controls the temperature of the first region and a second temperature control device that controls the temperature of the second region. And

According to this invention, the temperature control means for controlling the inside of the pressure vessel to at least two temperature regions having different temperatures controls the first temperature control device for controlling the temperature of the first region and the temperature of the second region. The second region can be set to a predetermined temperature so as not to have a predetermined pressure (saturated vapor pressure), while the first region is a temperature of the second region. Higher processing temperature. As a result, it is possible to perform the steam treatment under processing conditions that can improve the characteristics of the polysilicon film, the SiO ₂ gate insulating film, and the like.

  In the steam treatment apparatus of the present invention, the pressure vessel is composed of at least two pressure vessels, the at least two pressure vessels are connected via a connecting pipe, and one of the pressure vessels is the second region. It is characterized by that.

  The form of the pressure vessel constituting the present invention is not particularly limited as long as it has at least the first region and the second region, and the first region and the second region are provided in a single pressure vessel. As in the present invention, for example, it is composed of two pressure vessels, and the two pressure vessels constitute a first region and a second region, respectively, and both are connected via a connecting pipe. As a result, the pressure vessel may be a two-vessel integrated pressure vessel that results in the same pressure atmosphere.

  The steam processing apparatus of the present invention is a steam processing apparatus for a semiconductor device, wherein the steam is steam.

According to the present invention, it can be preferably used as a vapor processing apparatus capable of easily performing a water vapor treatment of a polysilicon film, a SiO ₂ gate insulating film or the like under a high pressure.

  The steam treatment method of the present invention for solving the above problems is a steam treatment method for an object to be processed in a pressure vessel having at least two temperature regions maintained at a predetermined pressure, wherein the two temperature regions Is a first region set to a predetermined temperature and a predetermined vapor pressure, and a second region is set to a temperature lower than the first region to generate saturated steam under the same pressure as the vapor pressure, The object to be processed is processed in the first region.

According to the present invention, first, a liquefied product (for example, water) is charged into the second region, and the second region is heated to a temperature at which the liquefied product evaporates to a predetermined saturated vapor pressure. Since the first region is in the same pressure vessel as the second region, the pressure is the same as the saturated vapor pressure, and the temperature of the first region is set higher than the temperature of the second region, The pressure of the first region can be steamed at a desired high temperature condition under a pressure considerably lower than the virtual value of the saturated vapor pressure at the set temperature of the first region. As a result, it is possible to perform the steam treatment under processing conditions that can improve the characteristics of the polysilicon film, the SiO ₂ gate insulating film, and the like.

  The vapor treatment method of the present invention is a vapor treatment method for a semiconductor device, wherein the vapor is water vapor.

According to the present invention, it can be preferably used as a vapor processing method capable of easily performing a water vapor treatment on a polysilicon film, a SiO ₂ gate insulating film or the like under a high pressure.

According to the steam processing apparatus and the steam processing method of the present invention, in the first region, steam processing can be performed at a desired high temperature condition under a pressure considerably lower than the virtual value of the saturated steam pressure at the set temperature of the first region. As shown in FIG. 4A, which is a conventional example, a pressure vessel that can withstand a predetermined pressure (eg, about 40 atmospheres) must be employed even when processing is performed at a relatively low temperature (eg, about 250 ° C.). The problem that the amount of water to be introduced into the inside must be accurately measured as shown in FIG. 4B, which is a conventional example, can be solved. Furthermore, a complicated control mechanism that actively controls the pressure while monitoring the pressure in the pressure vessel is not required. As a result, heat treatment can be performed at a desired temperature in a high-pressure steam atmosphere that can improve the characteristics of the polysilicon film, the SiO ₂ gate insulating film, and the like.

  Hereinafter, the steam processing apparatus and the steam processing method of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following description and drawing in the range which has the technical feature.

(Steam treatment equipment)
FIG. 1 is a cross-sectional configuration diagram illustrating an example of a steam processing apparatus of the present invention, and FIG. 2 is a cross-sectional configuration diagram illustrating another example of the steam processing apparatus of the present invention. The steam processing apparatus (1A, 1B) of the present invention controls a pressure vessel 11 for treating the workpiece 21 at a predetermined pressure P, and controls the inside of the pressure vessel 11 to at least two temperature regions having different temperatures. A first region 13 for processing the workpiece 21 under a predetermined vapor pressure P, the pressure vessel 11 being set to a predetermined temperature T1, and a first temperature control means 12. And a second region 14 that is set to a temperature T2 lower than the temperature T1 of the region 13 and generates saturated steam under the same pressure P as the vapor pressure P.

  The pressure vessel 11 is a vessel for processing the workpiece 21 at a predetermined pressure P, and includes a first region 13 for processing the workpiece 21 and a second region 14 for generating saturated steam. have. Although various forms can be given as the form of the pressure vessel 11, for example, as shown in FIG. 1, the pressure vessel 11 includes two pressure vessels 11A and 11B, and the two pressure vessels 11A and 11B are respectively connected to the first region 13 and the pressure vessel 11A. A second region 14 is formed, and both are connected via a connecting pipe 15, resulting in one pressure vessel 11 having the same pressure atmosphere, or a single unit as shown in FIG. The thing which has the pressure vessel 11 which has the 1st area | region 13 and the 2nd area | region 14 in the pressure vessel 11 which consists of a form can be illustrated.

  In addition, although the form which connected two pressure vessels 11A and 11B with the connecting pipe 15 is shown in the steam processing apparatus 1A of FIG. 1, one or two or more pressure vessels are made into the pressure vessel which has the 2nd area | region 14. The form connected via the connecting pipe may be sufficient.

  As shown in FIGS. 1 and 2, the pressure vessel 11 can be exemplified by a cylindrical shape similar to a conventionally known general pressure chamber, which includes a main body vessel 111 and a lid member 112. The main body container 111 and the lid member 112 are firmly sealed by a plurality of clamp members 115 provided at equal intervals on the outer periphery of the flange portions 113 and 114 provided respectively. In the present invention, it is not necessary to be a pressure vessel designed to be safe with respect to a pressure of 40 atm or more as in the prior art, but a pressure designed to be safe with respect to a pressure up to about 25 atm with a margin. A container is preferably used.

  The connecting pipe 15 of the pressure vessels 11A and 11B shown in FIG. Are firmly sealed by a plurality of clamp members 153 provided at equal intervals.

  A discharge port with a valve (not shown) for discharging the liquefied material 22 such as water may be provided at the bottom of the pressure vessel 11 shown in FIGS. 1 and 2 on the second region 14 side. Is not necessarily provided. Further, although not essential, a supply device (not shown) for supplying the liquefied material 22 such as water may be provided on the side wall or the like on the second region 14 side. If such a supply device is provided, a predetermined amount of liquefied material 22 (for example, water) is introduced into the pressure vessel 11 even after the workpiece 21 is placed in the pressure vessel 11 and the pressure vessel 11 is sealed. be able to. The liquefied product 22 (for example, water) may be stored at the bottom of the pressure vessel 11 as shown in FIGS. 1 and 2, or a receiving tray (not shown) for storing the liquefied product 22 is provided. The liquefied product 22 may be stored in a tray.

  The first region 13 and the second region 14 of the pressure vessel 11 are provided with temperature sensors (not shown) for detecting the temperature in each region. Similarly, a pressure sensor (not shown) for detecting the internal pressure P is provided in both or one of the first region 13 and the second region 14 of the pressure vessel 11. In addition, each member (the discharge port with a valve, a supply apparatus, a saucer, a temperature sensor, a pressure sensor) demonstrated in this paragraph and the preceding paragraph is provided in a pressure vessel in the aspect which does not inhibit the function of the pressure vessel used under high pressure. It is done.

Around the pressure vessel 11, temperature control means 12 for controlling the inside of the pressure vessel to at least two temperature regions is provided. 1 and 2, the temperature region refers to two temperature regions of the first region 13 and the second region 14, and the temperature control means 12 of each region is desired to set the temperature of the first region 13. A first temperature control device 12A for controlling the steam processing temperature T1 to a predetermined temperature T2 and a second temperature control device 12B for controlling the second region 14 to a predetermined temperature T2 that does not become a predetermined pressure (saturated vapor pressure). . According to this temperature control means 12, it is possible to perform the steam treatment under the processing conditions capable of improving the characteristics of the polysilicon film, the SiO ₂ gate insulating film and the like.

  Although each temperature control apparatus 12A, 12B is not specifically limited, For example, it is comprised by the heat generating body 121 and the controller (not shown) which controls the emitted-heat amount of the heat generating body 121. FIG. The heating element 121 constituting the first temperature control device 12A is arranged on the outer periphery of the pressure vessel 11 so as to control the temperature T1 of the first region 13, and the heating element 121 constituting the second temperature control device 12B is It arrange | positions at the outer periphery of the pressure vessel 11 so that temperature T2 of the 2nd area | region 14 is controllable.

  As shown in FIG. 1, when a plurality of pressure vessels are connected by the connecting pipe 15, it is necessary to control the temperature in the connecting pipe 15 with the temperature control device 12 </ b> C so that the temperature in the connecting pipe 15 does not become the temperature of each region. is there.

  The workpiece 21 is placed in the first region 13 in the pressure vessel 11. Although the mounting aspect of the workpiece 21 is not particularly limited, a dedicated mounting table 211 (see FIGS. 1 and 2) or the like is used depending on the shape and processing quantity of the workpiece 21. Such a dedicated mounting table or the like is fixed to the bottom surface or side wall of the pressure vessel 11 by welding or screwing.

As the object to be processed 21, an element having a polysilicon film, a SiO ₂ gate insulating film, or the like can be preferably cited, but other elements may be used. FIG. 3 is a schematic cross-sectional view showing an example of a polysilicon TFT having a polysilicon film and a SiO ₂ gate insulating film. In the case where the polysilicon film, the SiO ₂ gate insulating film, or the like is subjected to steam treatment, water is used as the liquefied material 22, and the water becomes steam to treat the workpiece.

3 includes a plastic substrate 30, an oxygen plasma-resistant inorganic layer 31 formed on the entire surface of the plastic substrate 30 as necessary, and at least a TFT element portion on the inorganic layer 31. The formed underlayer 32, the polysilicon film 33 (source side diffusion layer 33s, channel layer 33c, and drain side diffusion layer 33d) formed on the underlayer 32, and the SiO film formed on the polysilicon film 33 a _second gate insulation film 34, on the SiO ₂ gate insulating film 34, or SiO ₂ gate insulating film 34 electrode 35 formed through a contact hole (source electrode 35s, the gate electrode 35g and drain electrode 35d) and the chromatic is doing. Reference numeral 27 denotes a protective layer 37 made of silicon oxide or the like that covers the entire element.

3 is an element form having a top gate / top contact structure, but is not limited to such an example, and may be an element form having a bottom gate / top contact structure. An element configuration having a gate / bottom contact structure or a top gate / bottom contact structure may be employed. The processing apparatus of the present invention can be applied to the manufacturing process of the polysilicon TFT 39 shown in FIG. 3 and may be used at any timing of the process, but usually after forming the polysilicon film 33 and / or SiO 2. It is preferably used after the _two- gate insulating film 34 is formed.

(Steam treatment method)
Next, a steam processing method using the steam processing apparatus of the present invention will be described. The steam treatment method of the present invention is a steam treatment method for an object 21 in a pressure vessel 11 having at least two temperature regions 13 and 14 held at a predetermined pressure P. 14 is a first region 13 set to a predetermined temperature T1 and a predetermined vapor pressure P, and is set to a temperature T2 lower than the first region 13 and saturated steam under the same pressure P as the vapor pressure P. And a second region 14 for generating the target, and the workpiece 21 is processed in the first region 13.

  First, the lid member 112 is opened to open the pressure vessel 11, the workpiece 21 is placed on the placing table 211 in the first region 13, and water is added as the liquefied product 22 to the second region 14. Next, after the lid member 112 is closed and the pressure vessel 11 is sealed, the second region 14 and the second region 14 and the second region 14 are heated to a temperature T2 (for example, 180 ° C.) at which the water evaporates to a predetermined saturated water vapor pressure P (for example, 10 atmospheric pressure). One region 13 is heated. At this time, since the first region 13 is in the same pressure vessel 11 as the second region 14, the pressure P is the same as the saturated water vapor pressure P (for example, 10 atm). Next, the temperature T1 of the first region 13 is set to a temperature T1 (for example, 250 ° C.) higher than the temperature T2 (for example, 180 ° C.) of the second region 14. By doing so, in the first region 13, a desired vapor pressure (10 atm) is considerably lower than the virtual value (40 atm) of the saturated water vapor pressure at the set temperature T1 (250 ° C.) of the first region 13. Steam treatment can be performed at a high treatment temperature T1 (250 ° C.).

  As the liquefied product 22 to be put in the second region 14, water is usually used, but another medium may be used. Examples of media other than water include organic solvents such as alcohols such as ethanol and ketones such as acetone. In the present invention, the amount of the liquefied product 22 is not particularly limited. Even after the second region 14 is set to a predetermined temperature T2 and reaches the saturated vapor pressure P at the temperature T2, the second region 14 is used. It is preferable to add an amount of the liquefied product 22 remaining.

  As described above, the first region 13 is set as a predetermined temperature T1 (for example, 250 ° C.) and functions as a region for steaming the workpiece 21 under a predetermined vapor pressure P (for example, 10 atmospheric pressure). The second region 14 is a region for generating saturated steam at a temperature T2 (for example, 180 ° C.) lower than that of the first region 13 and under the same pressure P (for example, 10 atmospheres) as the vapor pressure P. Acts as

In particular, the vapor processing method of the present invention improves the characteristics of the insulating film and the characteristics of the insulating film / semiconductor interface by performing heat treatment at a desired temperature in a high-pressure steam atmosphere, such as a polysilicon film or a SiO ₂ gate insulating film. It is preferably used for vapor treatment of an element that can be improved. Usually, in the case of a polysilicon TFT, it is preferably performed after the formation of the polysilicon, and in the case of a MOSFET, it is performed after the formation of the SiO ₂ gate insulating film. Is preferred. A good transistor circuit can also be formed by performing the vapor treatment after the formation of the polysilicon TFT element or the MOSFET element. Furthermore, by performing the steam treatment of the present invention after the formation of the passivation insulating film of the solar cell, it is possible to improve the characteristics of the insulating film / semiconductor interface of the solar cell and manufacture a highly efficient solar cell circuit. In addition, the vapor treatment of the present invention can reduce defects contained in a silicon oxide substrate such as glass, and can realize an insulator base suitable for manufacturing an electronic device.

  The steam processing apparatus 1 of the present invention can withstand a predetermined pressure (for example, about 40 atm) even in the case of processing at a relatively low temperature (for example, about 250 ° C.) as shown in FIG. The problem that a pressure vessel that can be used must be adopted can be solved. Further, as shown in FIG. 4B, which is a conventional example, it is possible to eliminate the trouble of accurately measuring the amount of water to be introduced into the interior, and to monitor the pressure in the pressure vessel while monitoring the pressure in the pressure vessel. A complicated control mechanism for performing active control is also unnecessary.

It is a section lineblock diagram showing an example of a steam treatment device of the present invention. It is a cross-sectional block diagram which shows another example of the steam processing apparatus of this invention. It is a schematic cross section showing an example of a polysilicon TFT including a polysilicon film and a SiO ₂ gate insulating film. It is a cross-sectional block diagram which shows the example of the conventional water vapor processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A, 1B Steam processing apparatus 11, 11A, 11B Pressure vessel 12 Temperature control means 12A 1st temperature control apparatus 12B 2nd temperature control apparatus 13 1st area | region 14 2nd area | region 15 Connection pipe 21 Processed object 22 Liquid substance 111 Main body container 112 Lid member 113, 114, 116, 117, 151, 152 Flange portion 115, 153 Clamp member 121 Heating element 211 Mounting table 30 Plastic substrate 31 Inorganic layer 32 Underlayer 33 Polysilicon film 33s Source side diffusion layer 33c Channel layer 33d Drain Side diffusion layer 34 SiO ₂ gate insulating film 35 s Source electrode 35 g Gate electrode 35 d Drain electrode 37 Protective layer 39 Polysilicon TFT
P pressure (vapor pressure, saturated vapor pressure)
T1 First region temperature (high temperature)
T2 Second region temperature (low temperature)

Claims (6)

A steam processing apparatus comprising a pressure vessel for processing an object to be processed at a predetermined pressure, and temperature control means for controlling the inside of the pressure vessel to at least two temperature regions having different temperatures,
The pressure vessel is set to a predetermined temperature and a first region for processing the object to be processed under a predetermined vapor pressure, and is set to a temperature lower than the first region and the same pressure as the vapor pressure. And a second region for generating saturated steam.   The said temperature control means has a 1st temperature control apparatus which controls the temperature of the said 1st area | region, and a 2nd temperature control apparatus which controls the temperature of the said 2nd area | region, The Claim 1 characterized by the above-mentioned. Steam processing equipment.   2. The pressure vessel comprises at least two pressure vessels, the at least two pressure vessels are connected via a connecting pipe, and one of the pressure vessels is the second region. Or the steam processing apparatus of 2.   The steam processing apparatus according to claim 1, wherein the steam is a steam processing apparatus for a semiconductor device. A method for steaming a workpiece in a pressure vessel having at least two temperature regions maintained at a predetermined pressure,
The two temperature regions are set to a predetermined temperature and a predetermined vapor pressure, and a temperature lower than the first region is set to generate saturated steam under the same pressure as the vapor pressure. A steam treatment method, wherein the object to be treated is treated in the first region. The steam processing method of a semiconductor device, wherein the steam is steam.

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