JP2006216625A - Thin-film forming device, thin film, formation method thereof, semiconductor device, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film having improved quality for preventing an organic matter from adhering to a substrate. <P>SOLUTION: When introducing the substrate 1 into a treatment chamber 12 for treatment, the substrate 1 is introduced via two-stage load lock chambers 10, 11. The first-stage load lock chamber 10 performs substitution to an inert gas atmosphere as atmospheric pressure. The second-stage load lock chamber 11 has a baking heater 20. When pressure is reduced while the organic matter 5 adheres to the inner wall, it is eliminated and contaminates the substrate 1. However, the adhesion of the organic matter 5 to the substrate 1 is prevented by reducing the pressure in the second-stage load lock chamber 11 where no organic matters 5 adhere. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thin film formed on a substrate, a method for forming the thin film, a forming apparatus therefor, a semiconductor device using the thin film, and a forming method therefor.

  The characteristics of semiconductor devices, liquid crystal devices, etc. are greatly affected by the composition, bonding state, impurity concentration, surface shape, etc. of the thin film's extreme surface (several nm or less). Utilization of equipment is essential.

  All X-ray photoelectron spectrometers, Auger electron spectrometers, dynamic secondary ion mass spectrometers, time-of-flight secondary ion mass spectrometer analysis rooms, or some scanning atomic force microscopes, scanning tunneling microscopes Then, since analysis or observation is performed in an ultra-high vacuum chamber, the analysis sample is depressurized in the load lock chamber and then transported to the analysis chamber or observation chamber for analysis and observation.

  At this time, organic contamination adhering to the inner wall of the load lock chamber is desorbed, causing a problem of contaminating the analysis / observation sample surface.

  This is because the load lock is released to the atmosphere each time a sample is introduced and has no mechanism for cleaning and removing organic contamination, so that organic contamination is accumulated on the inner wall thereof.

  Fig. 4 is a graph showing the dependence of the total amount of organic substances adhering to a substrate left under atmospheric pressure and reduced pressure (Takeyuki Hayashi, "Study on Organic Contamination of Wafer Surfaces in a Vacuum Vacuum Apparatus", Doctoral Dissertation) However, under reduced pressure, organic substances contaminate the substrate surface in a very short time. In the case of a surface observation device, this organic matter causes a slight increase in roughness, or obstructs acquisition of the original surface shape. On the other hand, in the case of a surface analyzer, the sensitivity is reduced due to this organic substance, which hinders measurement. In addition, when analyzing samples containing carbon, or when analyzing organic substances adhering to the surface of the analyzed sample, they are disturbed by organic substances contaminated by the load lock.

  For example, in the case of an X-ray photoelectron spectrometer, as shown in Fig. 1, when the surface of Si is analyzed, peaks such as CC, CO, C = O, and COO are always observed from the sample surface exposed to the atmosphere. Is done. For example, when evaluating the amount of Si-C formed, if the peak of CC is large, reading the peak intensity of Si-C is hindered, so the detection sensitivity of Si-C decreases, the limit of quantification increases, and the accuracy of quantification increases. Problems such as degradation occur.

  For this reason, it is highly desirable to prevent organic contamination from adhering to the surface between the target treatment and measurement. As described above, when an analysis sample is transported through the load lock chamber to the analysis chamber, a reduced pressure atmosphere is inevitably generated. Therefore, organic substances are detached from the inner wall of the load lock to which organic contamination has adhered, and the sample surface is removed. To contaminate.

  On the other hand, silicon oxide dielectric film (hereinafter referred to as silicon oxide film), which is the gate insulating film of MOS (metal film electrode / silicon oxide dielectric film / silicon substrate) transistor, has low leakage current characteristics and low interface state. Various high insulation characteristics and high reliability are required, such as density, low threshold voltage shift, and low threshold variation characteristics.

  In order to obtain high insulating properties, various studies and inventions have been made on the oxidation method of the silicon oxide film, but the surface of the silicon substrate before oxidation is required to be as clean as possible. The silicon surface is naturally oxidized in the atmosphere, and a natural oxide film is formed to a thickness of about 0.5 to 1.5 nm, but this oxide film has poor insulating properties, so it must be etched away with a chemical solution containing HF. .

In order to remove metal, particles, and organic contamination, cleaning with oxidizing chemicals such as H ₂ SO ₄ and O ₃ is performed. At this time, since a chemical oxide film having poor insulating properties is formed on the silicon surface, the HF treatment must be performed after this step.

  In addition, a storage time of several minutes to several hours is required between cleaning and oxidation treatment. However, when HF treatment is performed, dangling bonds on the silicon surface are stabilized by termination with H atoms, and natural oxidation can be suppressed.

  High performance of semiconductor devices has been achieved by miniaturization of elements, but the thickness of the silicon oxide film has to be made extremely thin along with it, and the above-mentioned natural oxide film and HF treatment that can remove chemical oxide film is essential.

  On the other hand, when a silicon oxide film is formed by thermal oxidation, if a silicon substrate at room temperature is inserted into a high-temperature oxidation furnace, even if the inside of the furnace is kept in a non-oxidizing atmosphere, the surrounding atmosphere is involved and the original processing temperature is increased. There is a problem that an oxide film starts to be formed at a lower temperature.

In order to prevent this, a load lock chamber is provided as the front chamber of the furnace, and the oxygen and moisture concentration is reduced by an inert gas such as N ₂ and Ar, or a non-oxidizing atmosphere such as vacuum, and then the furnace. The substrate may be introduced into the substrate and heated in a non-oxidizing gas atmosphere. However, when both HF treatment and non-oxidizing atmosphere temperature rise are used, there is a problem that the insulating properties of the silicon oxide film are deteriorated.

  If H that terminates the silicon surface is desorbed by a temperature rise of 430 ° C or more, a dangling bond is formed. However, if organic contamination exists on the silicon surface, the silicon dangling bond reacts with the organic contamination, and SiC It is for forming.

  In the case of processes below 430 ° C, such as radical oxidation, plasma oxidation, etc., if H is incorporated into the film, it will adversely affect the insulation characteristics. Therefore, after removing H by irradiation with rare gas ions, etc. There is a need. In this case, dangling bonds are similarly formed. However, if organic contamination is present on the silicon surface, the dangling bonds on the silicon surface react with organic contamination to form SiC, so that the insulation characteristics deteriorate.

Fig. 1 (a) shows the XPS C1s core level photoelectron spectrum of the surface of the substrate after HF treatment heated to 800 ° C in Ar gas, which is a non-oxidizing atmosphere. The peak related to the Si-C bond is clear. Observed. As shown in Fig. 1 (b) and Fig. 1 (c), when the temperature is raised in O ₂ , which is an oxidizing atmosphere, and when the temperature of the SiO ₂ surface (substrate without HF treatment) is raised in Ar gas. In addition, no SiC peak is observed. The CC, CO, C = O, and COO peaks detected from the main peak to the high binding energy side are peaks related to organic substances contaminated from the atmosphere after the oxidation treatment and before measurement.

  FIG. 2 shows the temperature dependence of the SiC formation amount and the desorption temperature characteristics of the terminal H when the substrate after HF treatment is heated in vacuum. From this result, the formation mechanism of SiC is shown by the reaction model in FIG.

  As shown in FIG. 3 (a), the Si (100) surface after HF treatment has a structure in which Si atoms on the resurface are terminated with H in two of the four bonds. From 300 to 430 ° C, one of the Hs terminating the two bonds is desorbed, and Si forms a dangling bond, but the adjacent dangling bond bonds to form a dimer. The structure changes as shown in (b).

  The remaining H also desorbs and forms a dangling bond over 430-600 ° C, but it cannot be bonded due to the distance from the adjacent dangling bond, as shown in Fig. 3 (c). In addition, it becomes a very active surface covered with dangling bonds. On the other hand, part of the molecular structure of organic contamination decomposes and partly desorbs due to temperature rise, but there are also parts that remain on the surface. Since these have dangling bonds, they easily combine with dangling bonds on the Si surface to form SiC.

Since it is not easy to completely prevent organic contamination from adhering to the substrate and to suppress the formation of SiC, it has conventionally been in a non-oxidizing gas atmosphere containing an oxidizing gas such as several to several tens of percent O _2. A process is generally used in which the temperature is raised, an oxide film is formed at a low temperature (hereinafter referred to as a low temperature oxide film), and then the main oxidation is performed. Insulation characteristics of low-temperature oxide films are better than natural oxide films, chemical oxide films, entangled oxide films, etc., but they are worse than oxide films formed at high temperatures. Can be expected.

It is extremely difficult to remove organic contamination once adhered without changing the surface of the Si substrate, such as oxidation or nitridation, and without impairing surface flatness. Oxidizing gases such as O ₂ , H ₂ O, N ₂ O, NO, nitriding gases such as NH ₃ , N ₂ O, NO, rare gases such as Kr, Xe, Ar, inert gases such as N ₂ , Irradiation with reducing gas such as H ₂ , or plasma irradiation or ion irradiation thereof is impossible.

  Therefore, in order to realize a Si surface that excludes all of the uncontrolled oxide film, SiC, and H, and to form an oxide film that does not contain all of these, a method to prevent organic contamination from adhering to the substrate surface Development is essential. Here, an oxide film having an insulating property worse than that of the oxide film formed by the main oxidation, such as a natural oxide film, a chemical oxide film, an entrained oxide film, and a low-temperature oxide film, is referred to as an uncontrolled oxide film.

  To prevent organic contamination from adhering to the substrate surface, remove organic substances from cleaning chemicals, cleaning device atmosphere, clean room air, transfer container atmosphere, load lock chamber atmosphere, oxidation chamber atmosphere, process gas, etc. However, since organic materials are used in all parts, it is very difficult to completely prevent organic contamination.

  In order to completely remove organic pollution from the entire clean room atmosphere, a huge amount of air must be removed by chemical filters. A method of cleaning the inside of the substrate transfer container is realistic.

  Organic contamination in cleaning chemicals and process gases has already been suppressed to a low level. In addition, by using a high-purity inert gas near atmospheric pressure, it is possible to prevent organic contamination in the atmosphere in the cleaning apparatus and the atmosphere in the transfer container.

  However, in order to prevent the surrounding atmosphere from being involved in the ambient atmosphere in the load lock chamber and the oxidation treatment chamber, it is common to introduce a high purity inert gas or process gas after reducing the pressure once.

  When the pressure is reduced while the organic contamination adheres to the inner wall due to contact with the clean room atmosphere or diffusion from the back pump, the organic contamination adhering to the inner wall is detached from the inner wall, and part of it adheres to the substrate surface.

  FIG. 4 is a graph showing the dependence of the total amount of organic substances adhering to the substrate left under atmospheric pressure and reduced pressure on the standing time.

  Under reduced pressure, organic matter is contaminated in a very short time. However, the oxidation chamber is not opened to the atmosphere except during maintenance, and organic contamination is removed by combustion decomposition every time the oxidation treatment is performed, so organic contamination occurs when the gate valve to the load lock chamber is opened. In this case, it can only flow from the load lock chamber, be brought in a state of being attached to the substrate, or be brought back-spread from the back pump between the previous processing and the next processing.

  The amount of these contaminating the walls of the oxidation chamber and desorbing during depressurization and polluting the substrate is very small compared to that of the load-lock chamber that is open to the atmosphere and organic substances are not removed by oxidation. It is the load lock chamber that is easily contaminated with organic matter, and improvement of this part is the most important.

  In the above, the case of oxidation treatment was described as an example. However, even in the case of a thin film forming apparatus such as a CVD, the formation of SiC adversely affects the characteristics of the thin film. In addition, even if it is in an organic state without forming SiC, it is often the case that if it adheres to the substrate, the characteristics of the thin film will be affected. Therefore, prevention of organic contamination from adhering to the substrate is an important issue for general thin film forming apparatuses in general.

  The present invention has been made to solve the above-described problems, and its purpose is to suppress the adhesion of organic contamination to the substrate, thereby preventing uncontrolled oxide film free, organic contamination free, SiC free, and H free. And providing a thin film such as a silicon oxide film which is flat at the atomic level.

  Another object of the present invention is to suppress contamination of organic substances on the surface of an analysis sample by using a two-stage load lock.

  In order to achieve the above object, in the thin film forming apparatus of the present invention, the substrate is introduced from the outside, the first-stage load lock chamber for replacing with an inert gas while maintaining atmospheric pressure, the substrate is accommodated, and the inner wall A second-stage load lock chamber having a mechanism that does not adsorb organic substances on the substrate or removes adsorbed organic substances, a processing chamber having a film-forming mechanism for accommodating a substrate and forming a predetermined thin film, and one stage A gas atmosphere control unit for controlling the vacuum degree and gas concentration of the first load lock chamber, the second stage load lock chamber, and the processing chamber to predetermined values, a first stage load lock chamber, a second stage load lock chamber, and Transfer mechanism for moving substrates between processing chambers, and gate valves for opening and closing the first-stage loadlock chamber and second-stage loadlock chamber, and the second-stage loadlock chamber and processing chamber, respectively. Having And butterflies.

  Preferably, the gas atmosphere control unit includes an exhaust unit for exhausting the first-stage load lock chamber, the second-stage load lock chamber, and the processing chamber, an exhaust amount control gate valve for controlling an exhaust amount, and a gas And a gas flow rate control valve for controlling the gas flow rate.

  The second-stage load lock chamber preferably has a cleaning mechanism for detaching organic substances attached to the furnace inner wall or preventing the organic substances from attaching.

  The cleaning mechanism has, for example, a heating mechanism for baking the inner wall.

  The cleaning mechanism has, for example, a plasma generation mechanism that irradiates plasma on the inner wall.

  The thin film formation mechanism includes, for example, a plasma generation unit for performing radical oxidation and an oxidizing gas introduction unit.

  The thin film formation mechanism includes, for example, a plasma generation unit for performing radical nitridation and a nitriding gas introduction unit.

  The thin film formation mechanism includes, for example, a plasma generation unit for performing radical oxynitriding, and an introduction unit of an oxynitriding gas or an oxidizing gas and a nitriding gas.

  The thin film forming mechanism includes, for example, a heating unit for performing thermal oxidation and an oxidizing gas introduction unit.

  The thin film formation mechanism includes, for example, a heating unit for performing thermal nitridation and a nitriding gas introduction unit.

  The thin film formation mechanism includes, for example, a heating unit for performing thermal oxynitridation, and an introduction unit for an oxynitriding gas or an oxidizing gas and a nitriding gas.

  The thin film formation mechanism includes, for example, a heating unit for performing CVD film formation and a source gas introduction unit.

  The thin film formation mechanism includes, for example, a target for performing sputter film formation, an ion generation unit, a heating unit, and a source gas introduction unit.

  The plasma generation unit for performing radical oxidation, radical nitridation, and radical oxynitridation preferably includes a microwave generation unit, a microwave waveguide, and a radial line slot antenna.

  The plasma generation unit for performing radical oxidation, radical nitridation, and radical oxynitridation preferably includes parallel plate electrodes to which a high frequency can be applied.

Preferably, the CVD film formation is at least one gate insulating film thin film selected from the group consisting of SiO ₂ , SiN, SiON, HfO ₂ , HfSiO, and HfSiON.

  Preferably, the sputter film formation is a film formation of a base thin film for forming a Si or Hf gate insulating film.

  In addition, a transport container that is transported in an inert atmosphere at atmospheric pressure from at least a pretreatment device that performs a cleaning process passes through a second-stage load lock chamber that prevents adhesion of organic substances or removes organic substances and a gate valve. It is connected and has a mechanism that allows the substrate to be introduced into the second stage load lock chamber without touching the atmosphere. This transfer container has an inert gas atmosphere at atmospheric pressure. It may have a role.

  Alternatively, at least the treatment chamber of the pretreatment apparatus that performs the cleaning treatment or the load lock chamber thereof and the second stage load lock chamber that prevents the organic matter from adhering or removes the organic matter are directly connected via a gate valve. The processing chamber of the processing apparatus or its load lock chamber may have a role of a first-stage load lock chamber in which an inert gas atmosphere is maintained with atmospheric pressure.

  In this way, in the present invention, in order to reduce organic contamination adhesion to the substrate, a two-stage load lock chamber is used, and the first-stage load lock chamber is replaced with an inert gas at atmospheric pressure, and the second-stage load lock chamber is replaced. The load lock chamber has a mechanism that prevents organic substances from adhering to the inner wall, keeps it clean, reduces the pressure of the impurity gas, and introduces the substrate into the processing chamber.

  The first stage load lock chamber is opened to the atmosphere when the substrate is introduced, so organic contamination on the inner wall is unavoidable. However, by replacing it with an inert gas without reducing the pressure, the organic material is transferred from the inner wall to the substrate. Contamination can be prevented. However, the impurity gas concentration in the first-stage load lock chamber can only be lowered to a higher level than when the pressure is reduced.

  Next, the substrate is introduced into the second-stage load lock chamber. The second-stage load lock chamber has a mechanism that prevents organic substances from adhering to the inner wall or a mechanism that can remove organic substances.

  For example, this can be realized by always baking the inner wall or by providing a mechanism for generating plasma of a gas not containing C, such as an oxidizing gas, a hydrogen gas, and a nitriding gas.

  When a substrate is introduced from the first-stage load lock chamber to the second-stage load lock chamber, there is no organic contamination, but there is a small amount of impurity gas. In order to prevent this impurity gas from being brought into the processing chamber, the second-stage load lock chamber is depressurized, but the inner wall of the second-stage load lock chamber is free from organic contamination. There is no contamination.

  If the substrate is then introduced into the processing chamber, both organic contamination on the substrate surface and the introduction of impurity gas into the processing chamber can be prevented. If the pressure in the first-stage load lock chamber is 100 Torr or higher, the adhesion of organic contamination is almost negligible, but there is no problem even if the pressure is higher than atmospheric pressure.

  The above assumes that the substrate exposed to the atmosphere is transported, but it is transported in a container filled with inert gas without organic contamination, and the load lock chamber is not opened to the atmosphere. In the case of a mechanism capable of introducing the substrate into the load lock chamber, the first-stage load lock chamber can be omitted. That is, this transfer container plays the role of the first-stage load lock chamber.

  In addition, when the cleaning apparatus and the thin film forming apparatus are physically connected and transported through a transfer chamber free from organic contamination, the load lock chamber is not necessary. Since it is not open to the atmosphere, the first-stage load lock chamber is unnecessary. In addition, a second-stage load lock chamber is not required for providing the transfer chamber with a mechanism that prevents organic substances from adhering to the inner wall.

  However, in the present situation where cleaning is performed by batch processing, or in the present situation where a cleaning apparatus and various thin film forming apparatuses are separately developed, this method has a problem in terms of cost, and is superior to the embodiment of the present invention. There is.

  If the impurity gas is brought into the processing chamber without affecting the accuracy of the process and it is not necessary to keep the processing chamber at a reduced pressure, the second stage load lock chamber can be omitted. , The processing chamber plays the role of the second stage load lock chamber.

  However, at the present time when thin films used in semiconductor devices have become extremely thin, the process gas atmosphere is increasingly required to be highly purified, and the demand for the form of the present invention is high.

  As described above, by preventing organic contamination from the load-lock chamber wall to the substrate, the formation of SiC and the incorporation of organic substances into the film and film / substrate interface are prevented.

  In the present invention, the use of a two-stage load lock as a load lock chamber of a surface analysis device or surface observation device prevents organic substances from adhering to the analysis sample surface.

  According to the present invention, it is possible to prevent organic contamination from adhering to the silicon substrate at a low cost while maintaining the purity of the process gas atmosphere. For this reason, SiC is not formed even if H that terminates the silicon surface is removed immediately before the oxidation treatment. As a result, it becomes possible to form only a high-quality oxide film on the silicon surface of uncontrolled oxide film-free, organic contamination-free, SiC-free, and H-free, and the insulation characteristics can be improved.

  By preventing the organic contamination from adhering to the silicon substrate even in cases other than the oxidation treatment, it is possible to prevent the organic matter from being taken into the film and the film / substrate interface and to form a high-quality thin film. As a result, silicon oxide and other thin films can be made thinner than they are currently, and high performance of VLSI can be realized.

(Embodiment 1)
A dielectric film forming apparatus according to Embodiment 1 of the present invention will be described.

  As shown in FIG. 5, a first-stage load lock chamber 10 and a second-stage load lock chamber 11 are provided in the front chamber of the processing chamber 12. The two load lock chambers 10 and 11 and the processing chamber 12 have gas inlets 30, 31, 32, gas flow rate control valves 53, 54, 55, exhaust pumps 13, 14, 15, and displacement control gate valves, respectively. 43, 44, 45, and gas atmosphere control units 50, 51, 52 for controlling the degree of vacuum and gas concentration by controlling the gas flow rate control valves 53, 54, 55 and the displacement control valves 43, 44, 45, and It has.

  Gates are connected between the first-stage load lock chamber 10 and the outside, between the first-stage load lock chamber 10 and the second-stage load lock chamber 11, and between the second-stage load-lock chamber 11 and the processing chamber 12, respectively. Valves 40, 41 and 42 are installed. The second-stage load lock chamber 11 includes a baking heater 20 for preventing organic substances from adhering to the inner wall. In the processing chamber 12, an RLSA antenna 21, a waveguide 22, and a microwave generator 23 necessary for radical oxidation are installed.

After introducing an inert gas into the first-stage load lock chamber 10 and bringing it to atmospheric pressure, the gate valve 40 is opened to release the atmosphere, and the substrate 1 to be processed is placed in the first-stage load lock chamber 10 from outside the apparatus. It is introduced and the gate valve 40 is closed. At this time, the organic matter 5 slightly enters from the outside air. However, since the first-stage load lock chamber 10 is opened to the atmosphere for each treatment, the organic matter 5 is accumulated on the inner wall. The substrate 1 to be processed is supported on the transfer stage 2. In the first-stage load lock chamber 10, an inert gas such as N ₂ is introduced from the gas inlet 30 and exhausted by the exhaust pump 13, but the gas flow control valve 53 and the exhaust control gate valve 43 are opened and closed. By adjusting the gas atmosphere control unit 50, it is replaced with N ₂ while maintaining the atmospheric pressure. Since the load lock chamber 10 is not depressurized, the organic substance 5 is not detached from the inner wall of the load lock chamber 10, and the substrate 1 is not contaminated by the organic substance 5.

  On the other hand, the load lock chamber 11 in the second stage is evacuated and heated by the baking heater 20 in a steady state, and is kept in a state where the organic matter 5 does not adhere to the inner wall. After introducing an inert gas into the second-stage load lock chamber 11 to bring it to atmospheric pressure, the gate valve 41 is opened, the substrate 1 is moved onto the transfer stage 3, and the gate valve 41 is closed. At this time, since a small amount of impurity gas in the first-stage load lock chamber 10 partially flows into the second-stage load lock chamber 11, the second-stage load lock chamber 11 is once evacuated and then discharged. Purge with active gas. By evacuating and purging with inert gas several times, the impurity concentration is sufficiently reduced. Since the organic substance 5 does not adhere to the inner wall of the second-stage load lock chamber 11, the organic substance 5 does not contaminate the substrate 1 even if the pressure is reduced.

  In this case, the baking heater 20 is used to prevent the organic matter 5 from adhering to the inner wall, but the adhering organic contamination is generated by using a plasma not containing C, such as oxygen plasma, hydrogen plasma, nitrogen plasma, etc. A method of cleaning the inner wall is also effective.

  The processing chamber 12 is evacuated in a steady state. If the treatment is not performed immediately before, there is a small amount of organic matter adhering to the inner wall due to back diffusion from the exhaust pump 15, etc., so a dummy substrate is once inserted and the inner wall is covered with oxygen plasma, hydrogen plasma or nitrogen plasma. It is preferable to clean it. In the case of a thermal oxidation furnace, it is preferable to burn and remove the organic substance 5 by thermal oxidation. Even in the case of a CVD furnace, the organic substance 5 is removed by flowing an oxidizing gas and raising the temperature.

After the second-stage load lock chamber 11 and the processing chamber 12 have the same degree of vacuum of about 1 Kpa, the gate valve 42 is opened, the substrate 1 is moved to the processing stage 4, and the gate valve 42 is closed. After the processing stage 4 is heated to the process temperature, microwaves are supplied from the microwave generator 23 to the radial line slot antenna 21 through the waveguide 22, and plasma is generated immediately below the radial line slot antenna 21. This plasma generates a Kr gas plasma, supplies Kr radicals and Kr ions to the surface of the substrate 1, and removes H that terminates the surface of the substrate 1. Thereafter, the substrate 1 is oxidized by oxygen radicals generated by Kr / O ₂ or the like.

Here, an example of Kr / O ₂ radical oxidation using RLAS has been shown, but in the case of radical oxidation by parallel plate, plasma generated by other methods, or inert gases such as Xe and Ar other than Kr. The same applies when used. The same applies to thermal oxidation, CVD oxide film formation, radical nitridation, thermal nitridation, radical oxynitridation, thermal oxynitridation, sputtering, and other thin film formations. What is important is that the two-stage load lock chambers 10 and 11 make the organic substance 5, SiC, and other H and uncontrolled oxide films not present on the surface of the substrate 1 immediately before processing.

(Embodiment 2)
A thin film forming apparatus according to Embodiment 2 of the present invention will be described.

  As shown in FIG. 6, a first-stage load lock chamber 10 and a second-stage load lock chamber 11 are provided in the front chamber of the processing chamber 12. The load lock chamber 11 and the processing chamber 12 in the second stage include gas inlets 31 and 32, gas flow rate control valves 54 and 55, exhaust pumps 14 and 15, exhaust amount control gate valves 44 and 45, respectively, Gas atmosphere control units 51 and 52 for controlling the degree of vacuum and the gas concentration by controlling the gas flow rate control valves 54 and 55 and the displacement control valves 44 and 45 are provided.

  Gate valves 46, 40, 42 between the first-stage load lock chamber 10 and the outside, between the outside and the second-stage load lock chamber 11, and between the second-stage load lock chamber 11 and the processing chamber 12, respectively. Is installed. The second-stage load lock chamber 11 includes a baking heater 20 for preventing organic substances from adhering to the inner wall. In the processing chamber 12, a radial line slot antenna (RLSA antenna) 21, a waveguide 22, and a microwave generator 23 necessary for radical oxidation are installed.

  The first-stage load lock chamber 10 is purged with an inert gas, for example, by another pretreatment device such as a cleaning device, and is used as a transfer container for transfer to the thin film forming apparatus. The first-stage load lock chamber 10 is connected to the second-stage load lock chamber 11, and the gate valve 46 and the gate valve 40 are opened to remove the substrate 1 from the first-stage load lock chamber 10. A mechanism capable of transporting to the load lock chamber 11 is provided.

  The first-stage load lock chamber 10 is brought to atmospheric pressure by introducing an inert gas by another device. On the other hand, the load lock chamber 11 in the second stage is evacuated and heated by the baking heater 20 in a steady state so that organic substances do not adhere to the inner wall. An inert gas is introduced into the second-stage load lock chamber 11 to bring it to atmospheric pressure, and after the first-stage load lock chamber 10 and the second-stage load lock chamber 11 are connected, the gate valve 46 and the gate valve 40 are connected. The substrate 1 to be processed is introduced into the second-stage load lock chamber 11, and the gate valve 46 and the gate valve 40 are closed.

  At this time, there is no intrusion of outside air, and the inner wall of the second-stage load lock chamber 11 is not contaminated with organic matter. However, since a small amount of impurity gas in the first-stage load lock chamber 10 partially flows into the second-stage load lock chamber 11, the second-stage load lock chamber 11 is evacuated and then inactive. Purge with gas. By evacuating and purging with inert gas several times, the impurity concentration is sufficiently reduced. Since organic matter does not adhere to the inner wall of the second-stage load lock chamber 11, the organic matter does not contaminate the substrate 1 even if the pressure is reduced. The substrate 1 to be processed is supported on the transfer stage 3.

  Here, the baking heater 20 is used in order to prevent organic substances from adhering to the inner wall, but the inner wall is cleaned by generating plasma using a gas that does not contain C, such as oxygen plasma and nitrogen plasma, from the adhering organic contamination. The method is also effective.

  The processing chamber 12 is evacuated in a steady state. If no treatment has been performed immediately before, there is a trace amount of organic matter adhering to the inner wall due to reverse diffusion from the exhaust pump 15, so a dummy substrate is inserted and the inner wall is cleaned with oxygen plasma or nitrogen plasma. It is preferable to leave. In the case of a thermal oxidation furnace, it is better to burn off organic substances by thermal oxidation. Even in the case of a CVD furnace, an organic gas is removed by flowing an oxidizing gas and raising the temperature.

After the second-stage load lock chamber 11 and the processing chamber 12 have the same degree of vacuum of about 1 KPa, the gate valve 42 is opened, the substrate 1 is moved to the processing stage 4, and the gate valve 42 is closed. After the processing stage 4 is heated to the process temperature, microwaves are supplied from the microwave generator 23 to the radial line slot antenna 21 through the waveguide 22, and plasma is generated immediately below the radial line slot antenna 21. This plasma generates a Kr gas plasma, supplies Kr radicals and Kr ions to the surface of the substrate 1, and removes H that terminates the surface of the substrate 1. Thereafter, the substrate 1 is oxidized by oxygen radicals generated by Kr / O ₂ or the like.

Here, an example of Kr / O ₂ radical oxidation using RLAS is shown, but in the case of radical oxidation by parallel plates, plasma generated by other methods, and inert gases such as Xe and Ar other than Kr are used. The same applies to the case where there is. The same applies to thermal oxidation, CVD oxide film formation, radical nitridation, thermal nitridation, radical oxynitridation, thermal oxynitridation, and other thin film formation. What is important is that the two-stage load lock chambers 10 and 11 make the organic substance, SiC, other H and uncontrolled oxide films not present on the surface of the substrate 1 immediately before the processing.

(Embodiment 3)
A surface analysis apparatus or surface inspection apparatus according to Embodiment 3 of the present invention will be described.

  As shown in FIG. 7, a first-stage load lock chamber 10 and a second-stage load lock chamber 11 are provided in the front chamber of the processing chamber (analysis chamber or observation chamber) 12. The two load lock chambers 10 and 11 and the processing chamber 12 have gas inlets 30, 31, 32, gas flow rate control valves 53, 54, 55, exhaust pumps 13, 14, 15, and displacement control gate valves, respectively. 43, 44, 45, the gas flow rate control valves 53, 54, 55 and the displacement control valves 43, 44, 45 are controlled to control the degree of vacuum and gas concentration. And.

  Gates are connected between the first-stage load lock chamber 10 and the outside, between the first-stage load lock chamber 10 and the second-stage load lock chamber 11, and between the second-stage load-lock chamber 11 and the processing chamber 12, respectively. Valves 40, 41 and 42 are installed. The second-stage load lock chamber 11 is provided with a baking heater 20 for preventing organic substances from adhering to the inner wall. The processing chamber 12 includes an X-ray source (excitation source) 24 and a detector 25 necessary for analysis and observation.

After introducing an inert gas into the first-stage load lock chamber 10 and bringing it to atmospheric pressure, the gate valve 40 is opened to release the atmosphere, and the substrate to be analyzed or observed from the outside of the apparatus into the first-stage load lock chamber 10 1 is introduced and the gate valve 40 is closed. At this time, the organic matter slightly enters from the outside air, but the first-stage load lock chamber 10 is opened to the atmosphere for each treatment, so that the organic matter 5 is accumulated on the inner wall. The substrate 1 to be processed is supported on the transfer stage 2. In the first-stage load lock chamber 10, an inert gas such as N ₂ is introduced from the gas inlet 30 and exhausted by the exhaust pump 13, but the gas flow control valve 53 and the exhaust control gate valve 43 are opened and closed. By adjusting the gas atmosphere control unit 50, it is replaced with N ₂ while maintaining the atmospheric pressure. Since the load lock chamber 10 is not depressurized, the organic substance 5 is not detached from the inner wall of the load lock chamber 10, and the substrate 1 is not contaminated by the organic substance 5.

  On the other hand, the load lock chamber 11 in the second stage is evacuated and heated by the baking heater 20 in a steady state so that organic substances do not adhere to the inner wall. After introducing an inert gas into the second-stage load lock chamber 11 to bring it to atmospheric pressure, the gate valve 41 is opened, the substrate 1 is moved onto the transfer stage 3, and the gate valve 41 is closed. At this time, since a small amount of impurity gas in the first-stage load lock chamber 10 partially flows into the second-stage load lock chamber 11, the second-stage load lock chamber 11 needs to be evacuated once. When the processing chamber 12 is in an ultra-high vacuum, the load lock chamber is exhausted to at least a high vacuum. Since organic matter does not adhere to the inner wall of the second stage load lock chamber 11, even if the pressure is reduced, the organic matter does not contaminate the analysis sample.

  Here, the baking heater 20 is used in order to prevent organic substances from adhering to the inner wall, but the inner wall is cleaned by generating plasma using a gas that does not contain C, such as oxygen plasma and nitrogen plasma, from the adhering organic contamination. The method is also effective.

  The processing chamber 12 is evacuated to an ultra-high vacuum by an ion pump or the like during normal operation. In order to achieve ultra-high vacuum, the inner wall of the analysis chamber has already been cleaned by baking or the like.

  After raising the second-stage load lock chamber 11 to a vacuum level higher than the high vacuum, the gate valve 42 is opened, the analysis sample 1 is moved to the processing stage 4, and the gate valve 42 is closed. Analysis or observation is performed by irradiating the surface of the sample with X-rays, electron beams, ion beams, or bringing a probe closer. FIG. 7 shows an example of an X-ray photoelectron spectrometer. The X-ray source 24 irradiates the surface of the analysis sample with X-rays, and the photoelectrons jumping out of the analysis sample are detected by a detector 25 including an energy spectrometer. What is important is that the organic material is not present on the substrate surface immediately before the analysis by the two-stage load lock chamber 11.

  According to the present invention, it is possible to prevent organic contamination from adhering to the substrate surface and to form a thin film free from organic contamination. In the case of radical oxidation, the insulating properties of the silicon oxide film are improved by simultaneously preventing the formation of an uncontrolled oxide film, the adhesion of organic contamination, the formation of SiC, and the incorporation of H into the silicon oxide film. As a result, the present invention can be applied to a VLSI capable of reducing the silicon oxide film thickness and increasing the reliability of other thin films and realizing higher performance.

(A) The surface of the substrate after HF treatment was heated to 800 ° C. in Ar gas, (b) is the surface of the substrate after HF treatment heated to 800 ° C. in O ₂ gas, (c) is the surface of HF the substrate on which SiO ₂ is formed on the surface without the treatment temperature was raised to 800 ° C. in an Ar gas surface, a view showing the XPS C1s core level photoelectron spectra. It is a figure showing the graph which shows the temperature dependence of the amount of SiC formation, and the desorption temperature characteristic of termination | terminus H when the board | substrate after HF processing is heated in a vacuum. (A)-(c) is the model figure which showed a mode that Si (100) surface after HF processing desorbs H by temperature rising, reconfigure | reconstructs, and forms SiC. It is a figure showing the graph which shows the leaving time dependence of the organic substance total amount adhering to the board | substrate left to stand in a pressure-reduced atmosphere and atmospheric pressure. It is a figure showing an example of the thin film formation apparatus (radical oxidation apparatus) which prevented adhesion of the organic substance shown in Embodiment 1. FIG. It is a figure showing an example of the thin film formation apparatus (radical oxidation apparatus) which prevented adhesion of the organic substance shown in Embodiment 2. It is a figure showing an example of the surface analysis apparatus or surface inspection apparatus shown in Embodiment 3.

Explanation of symbols

1 Board
2 Transfer stage
3 Transfer stage
4 Processing stage
5 Organic matter
10 1st stage load lock room
11 Second stage load lock room
12 Processing chamber
13 Exhaust pump
14 Exhaust pump
15 Exhaust pump
20 Baking heater
21 Radial line slot antenna
22 Microwave waveguide
23 Microwave generator
24 X-ray source
25 Detector
30 Gas inlet
31 Gas inlet
32 Process gas inlet
40 Gate valve
41 Gate valve
42 Gate valve
43 Displacement control gate valve
44 Displacement control gate valve
45 Displacement control gate valve
46 Gate valve for transfer container
50 Gas atmosphere control unit
51 Gas atmosphere controller
52 Gas atmosphere controller
53 Gas flow control valve
54 Gas flow control valve
55 Gas flow control valve

Claims (50)

A first-stage load-lock chamber that can accommodate a predetermined sample introduced from outside and can be replaced with an inert gas while maintaining 10 kPa to 1000 kPa;
A two-stage load lock chamber having a mechanism for storing a predetermined sample and not adsorbing organic substances on the inner wall or having a mechanism capable of removing adsorbed organic substances.   2. The two-stage load lock chamber according to claim 1, which is used as a load lock chamber of a surface analysis apparatus.   The two-stage load lock chamber according to claim 1, wherein the load lock chamber is used as a load lock chamber of a surface observation device.   The surface analyzer is an X-ray photoelectron spectrometer, an Auger electron spectrometer, a dynamic secondary ion mass spectrometer, a time-of-flight secondary ion mass spectrometer, a scanning atomic force microscope, or a scanning tunneling microscope. The two-stage load lock chamber according to claim 1 or 2, characterized by the above. A first-stage load lock chamber that introduces a substrate from the outside and replaces it with an inert gas while maintaining the atmospheric pressure at 10 Kpa to 1000 Kpa;
A second-stage load-lock chamber that houses a substrate and has a mechanism that does not adsorb organic substances on the inner wall or removes adsorbed organic substances;
A processing chamber having a film forming mechanism for accommodating a substrate and forming a predetermined thin film;
A gas atmosphere control unit for controlling the vacuum degree and gas concentration of the first-stage load lock chamber, the second-stage load lock chamber, and the processing chamber to predetermined values, respectively;
A transport mechanism for moving the substrate between the first-stage load lock chamber, the second-stage load lock chamber, and the processing chamber;
1. A thin film forming apparatus comprising: a gate valve for opening and closing a first stage load lock chamber and a second stage load lock chamber, and a second stage load lock chamber and a processing chamber, respectively, for passing the substrate.   The gas atmosphere control unit introduces gas, an exhaust unit for exhausting the first-stage load lock chamber, the second-stage load lock chamber, and the processing chamber, an exhaust amount control gate valve for controlling the exhaust amount, and gas The thin film forming apparatus according to claim 5, further comprising a gas introduction unit for controlling the gas flow rate and a gas flow rate control valve for controlling a gas flow rate.   7. The thin film forming apparatus according to claim 5, wherein the second-stage load lock chamber has a cleaning mechanism for detaching organic substances adhering to a furnace inner wall or preventing adhesion of organic substances. .   The thin film forming apparatus according to claim 7, wherein the cleaning mechanism has a heating mechanism for baking an inner wall.   The thin film forming apparatus according to claim 7, wherein the cleaning mechanism includes a plasma generation mechanism that irradiates plasma on an inner wall.   The thin film formation apparatus according to claim 5, wherein the thin film formation mechanism includes a plasma generation unit for performing radical oxidation and an oxidizing gas introduction unit.   The thin film forming apparatus according to claim 5, wherein the thin film forming mechanism includes a plasma generation unit for performing radical nitridation and a nitriding gas introduction unit.   The said thin film formation mechanism has a plasma production | generation part for performing radical oxynitriding, and the introduction part of oxynitriding gas or oxidizing gas, and nitriding gas, The said any one of Claims 5-9 characterized by the above-mentioned. Thin film forming equipment.   The thin film forming apparatus according to claim 5, wherein the thin film forming mechanism includes a heating unit for performing thermal oxidation and an oxidizing gas introduction unit.   The thin film forming apparatus according to claim 5, wherein the thin film forming mechanism includes a heating unit for performing thermal nitriding and a nitriding gas introduction unit.   The said thin film formation mechanism has a heating part for performing thermal oxynitriding, and an introduction part of an oxynitriding gas or oxidizing gas and a nitriding gas. Thin film forming equipment.   The thin film forming apparatus according to claim 5, wherein the thin film forming mechanism includes a heating unit for performing CVD film formation and a source gas introduction unit.   The thin film forming apparatus according to any one of claims 5 to 9, wherein the thin film forming mechanism includes a target for performing sputter film formation, an ion generation unit, a heating unit, and a source gas introduction unit.   The plasma generation unit for performing the radical oxidation, radical nitridation, and radical oxynitridation includes a microwave generation unit, a microwave waveguide, and a radial line slot antenna. The thin film forming apparatus described in 1.   The thin film forming apparatus according to claim 10, wherein the plasma generation unit for performing the radical oxidation, radical nitridation, and radical oxynitridation includes parallel plate electrodes to which a high frequency can be applied. The CVD film formation is a film formation of at least one gate insulating film thin film selected from the group consisting of SiO ₂ , SiN, SiON, HfO ₂ , HfSiO, and HfSiON. Thin film forming equipment.   The thin film forming apparatus according to claim 17, wherein the sputter film formation is a film formation of a base thin film for forming a gate insulating film of Si or Hf. A transport container transported in an inert atmosphere at atmospheric pressure from at least a pretreatment device for performing a cleaning process is connected to a second stage load lock chamber for preventing adhesion of organic substances or removing organic substances via a gate valve. , It has a mechanism that can introduce the substrate into the second stage load lock chamber without touching the atmosphere,
The thin film forming apparatus according to any one of claims 5 to 21, wherein the transfer container has a role of a first-stage load lock chamber that maintains an inert gas atmosphere at atmospheric pressure. At least the processing chamber of the pretreatment device that performs the cleaning process or its load lock chamber and the second stage load lock chamber that prevents the adhesion of organic substances or removes organic substances are directly connected via a gate valve,
The process chamber of this pretreatment apparatus or its load lock chamber has a role of a first-stage load lock chamber in which an inert gas atmosphere is maintained at atmospheric pressure. The thin film forming apparatus described. A dielectric film formed on a processing substrate,
The dielectric film according to claim 1, wherein the dielectric film does not include an uncontrolled oxide film. The Si-C bond is contained in the dielectric film at a concentration of 1E + 12 atoms / cm ² or less in the vicinity of the interface between the dielectric film and the surface of the processing substrate. Dielectric film. 26. The dielectric film according to claim 24, wherein the dielectric film contains H at a concentration of 1E + 20 atoms / cm ³ or less.   27. The dielectric film according to claim 24, wherein a roughness of an interface between the dielectric film and the surface of the processing substrate in the dielectric film is an RMS value of 0.2 nm or less. In a semiconductor device comprising a processing substrate, a dielectric film formed on the processing substrate, and an electrode formed on the dielectric film,
The semiconductor device, wherein the dielectric film does not include an uncontrolled oxide film. 30. The semiconductor according to claim 28, wherein the dielectric film includes Si-C bonds at a concentration of 1E + 12 atoms / cm < ² > or less in the vicinity of the interface between the dielectric film and the surface of the processing substrate. apparatus. 30. The semiconductor device according to claim 28, wherein the dielectric film contains H at a concentration of 1E + 20 atoms / cm ³ or less.   31. The semiconductor device according to claim 28, wherein the dielectric film has an RMS roughness of 0.2 nm or less in terms of an interface between the dielectric film and the surface of the processing substrate.   A method for forming a thin film, characterized in that, when forming a dielectric film on the surface to be treated, the load-lock chamber is replaced with an inert gas atmosphere at a pressure higher than atmospheric pressure.   33. The thin film according to claim 32, wherein when forming the dielectric film on the surface of the processing substrate, the pressure is reduced using a load lock chamber whose inner wall is baked and introduced into the processing chamber. Forming method.   When forming a dielectric film on the surface of the processing substrate, the inner wall is decompressed using a load-lock chamber that is plasma-cleaned by plasma of a gas not containing carbon such as oxygen, hydrogen, or nitrogen, and introduced into the processing chamber. The method for forming a thin film according to claim 28.   A method of manufacturing a semiconductor device, characterized in that, when a dielectric film is formed on a surface of a processing substrate, the load lock chamber is replaced with an inert gas atmosphere at a pressure higher than atmospheric pressure.   36. The method of manufacturing a semiconductor device according to claim 35, wherein when forming the dielectric film on the surface of the processing substrate, the pressure is reduced using a load-lock chamber whose inner wall is baked and introduced into the processing chamber. Method.   When forming a dielectric film on the surface of the processing substrate, the inner wall is decompressed using a load-lock chamber that is plasma-cleaned by a plasma of a gas not containing carbon such as oxygen, hydrogen, or nitrogen, and introduced into the processing chamber. 36. A method of manufacturing a semiconductor device according to claim 35.   28. The dielectric film according to claim 24, wherein the processing substrate is a silicon substrate.   32. The semiconductor device according to claim 28, wherein the processing substrate is a silicon substrate.   The method for forming a thin film according to any one of claims 32 to 34, wherein the processing substrate is a silicon substrate.   38. A method of manufacturing a semiconductor device according to claim 35, wherein the processing substrate is a silicon substrate.   The dielectric film according to claim 24, wherein the dielectric film is formed by radical oxidation, plasma oxidation, or thermal oxidation.   40. The semiconductor device according to claim 28, wherein the dielectric film is formed by radical oxidation, plasma oxidation, or thermal oxidation.   41. The method for forming a thin film according to claim 32, wherein the dielectric film is formed by radical oxidation, plasma oxidation, or thermal oxidation.   42. The method of manufacturing a semiconductor device according to claim 35, wherein the dielectric film is formed by radical oxidation, plasma oxidation, or thermal oxidation.   The dielectric film according to any one of claims 24 to 27, 38, or 42, wherein the method of forming the dielectric film is CVD or sputtering.   45. The semiconductor device according to claim 28, wherein the dielectric film is formed by CVD or sputtering.   45. The method for forming a thin film according to claim 32, wherein the method for forming the dielectric film is CVD or sputtering.   46. The method of manufacturing a semiconductor device according to claim 35, wherein the dielectric film is formed by CVD or sputtering. A thin film formed on a processing substrate,
The thin film does not contain an uncontrolled oxide film, and contains an organic substance at a concentration of 1E + 12 atoms / cm ² or less near the interface between the thin film and the surface of the processing substrate.

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