KR101087821B1 - Method for manufacturing semiconductor light emitting element - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention aims to provide a method for manufacturing a high performance semiconductor light emitting device substrate while reducing the production time.
In order to solve the above problems, the method for manufacturing a semiconductor light emitting device substrate of the present invention includes a substrate heating step S3 for heating the substrate, a substrate cleaning step S6 for cleaning the substrate S, and a substrate. The radiant heat is generated by the dielectric layer forming step (S7) for depositing the dielectric layers (H, L) on (S), the substrate heating stop step (S8) for stopping heating of the substrate, and the cooling means (11, 12, 13). Cooling step (S9) for cooling the substrate (S) and the substrate holding and holding means (3) by absorbing the water, and the reflective layer forming step (S11) for depositing the reflective layer (R) on the dielectric layers (H, L). It is characterized by being provided.

Description

Method for manufacturing semiconductor light emitting element substrate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor light emitting device substrate, and more particularly, to a method of manufacturing a high performance semiconductor light emitting device substrate, which shortens the manufacturing time.

BACKGROUND ART Since semiconductor light emitting devices (LEDs) have low power consumption, long lifespan, and high luminous efficiency, practical use as a light source has been advanced. In the field of semiconductor light emitting devices, GaN compound semiconductors such as GaN, GaAlN, InGaN and the like have been widely used for visible light emitting devices, high temperature operating electronic devices, and the like.

In the manufacture of GaN compound semiconductors, sapphire substrates are generally used as crystal substrates in order to grow a semiconductor film on the substrate surface. Since the sapphire substrate is insulative, an electrode cannot be provided on the back side of the sapphire substrate with respect to the substrate surface on which the light emitting layer made of a GaN compound is provided, and the p electrode and the n electrode are provided on the same surface as the light emitting layer. .

In more detail, a buffer layer, an n-type GaN-based compound layer, a GaN-based light emitting layer, and a p-type GaN-based compound layer are laminated on the sapphire substrate in this order, and a p-electrode is provided thereon. In addition, it is common for some n-type GaN compound layers to be exposed by etching to provide an n-type electrode.

Therefore, an n-type GaN compound layer, a GaN-based light emitting layer, and a p-type GaN compound layer are sequentially stacked on the sapphire substrate, and a p-electrode and an n-electrode are provided on the same plane as each of these layers, thereby forming a semiconductor light emitting element. do.

When the semiconductor light emitting element having the above configuration is mounted on various devices, the mounting method is largely divided into two types: face up mounting and face down mounting. Face-up mounting is the method of arrange | positioning a board | substrate to a device side with the surface in which the electrode was formed upward, and is a structure which takes out light from an electrode side. On the other hand, face-down mounting is the method of arrange | positioning an electrode to a device side with the surface in which the electrode was formed downward, and is a structure which takes out light from a board | substrate side.

In the face-up mounting, the light extraction efficiency can be improved by forming a reflective layer on a surface opposite to the surface on which the respective layers and electrodes on the sapphire substrate are formed. As a material used for a reflection layer, aluminum (Al), silver (Ag), etc. which have high reflectance in the light emission wavelength range (about 450-470 nm) of a blue LED are used. In addition, it is known that the reflection efficiency in the light emission wavelength range of a blue LED is about 92% in Al and about 95% in Ag.

Further, a higher reflectance can be obtained by providing a plurality of dielectric layers, which are additionally a reflective reflection layer, between the sapphire substrate and the reflective layer made of the metal. The dielectric layer is formed by alternately stacking a dielectric layer H made of a material having a high refractive index and a dielectric layer L made of a material having a low refractive index so as to have an optical film thickness of (λ) / 4 for a wavelength of 460 nm, respectively. do.

The structure of a semiconductor light emitting element substrate having such dielectric layers having different refractive indices is briefly expressed as in Equation 1 or 2 below.

Sapphire substrate / aL (HL) ^b / Al (or Ag)... (Equation 1)

Sapphire substrate / cH (LH) ^d L / Al (or Ag)... (Equation 2)

In this case, a, b, c, and d are integers.

In the semiconductor light emitting element substrate having the structure represented by Equation 1 or 2, the material of the high refractive index dielectric layer H, such as TiO ₂ , Ta ₂ O ₅ , Nb ₂ O _5, or the like, is a material of the low refractive index dielectric layer L. As the SiO ₂ or the like is used.

When TiO ₂ is used as the material of the high refractive index dielectric layer H and SiO ₂ is used as the material of the low refractive index dielectric layer L, the calculation results of the optical properties are as shown in FIG. As shown in Fig. 7, the high refractive index dielectric layer (H) and the low refractive index dielectric layer (L) are preferable because the higher the b and the d, the higher the reflectance can be obtained. However, when there are many b and d, process time will become long, and heat conduction will worsen with respect to heat_generation | fever of a light emitting layer, 2 <b <4 is suitable.

In depositing the dielectric layer on a sapphire substrate, vacuum deposition is generally used. In the vacuum deposition method, a vapor deposition method in which a densification is carried out by irradiating ions to a deposition layer deposited on a substrate when the dielectric material is evaporated toward the substrate surface in a vacuum chamber, that is, an ion assist deposition method, is known.

In this vapor deposition method, a relatively low energy ion beam (gas ion) is irradiated to the substrate by the ion source, and electrons are irradiated to the substrate by a neutralizer called a neutralizer. This configuration makes it possible to produce a dense optical thin film by the kinetic energy of the ion beam, while neutralizing the charge accumulated on the substrate by the ion beam (for example, Patent Document 1). In addition, crystallization of the deposited dielectric layer can be prevented, and a thin film excellent in optical characteristics and excellent in environmental resistance can be formed.

However, in the technique described in Patent Literature 1, the evaporation source is at a high temperature of about 2000 ° C. when the dielectric layer is formed. In the case of using an ion source for irradiating an ion beam, the ion source itself becomes a high temperature and the substrate is heated with the irradiation of ions. The substrate temperature at this time depends on the material of the dielectric layer, the thickness to be deposited, the number of layers, and the like, but the substrate temperature is heated to about 100 ° C or higher.

As a result, the substrate is heated by radiant heat using the evaporation source or the ion source as a heat source, and the substrate temperature becomes high after the deposition of the dielectric layer. However, when forming a reflective layer of Al, Ag, or the like on the dielectric layer, it is necessary to cool the substrate temperature to 50 ° C. or lower to form a film in order to obtain good optical characteristics. Therefore, in the manufacture of a semiconductor light emitting device substrate, in order to form a plurality of dielectric layers and reflective layers such as Al on the back surface of the sapphire substrate, it is necessary to provide a cooling time for cooling the substrate, and manufacturing requires a long time. There was a problem.

As a technique for preventing such a rise in substrate temperature, Patent Literature 2 proposes a technique for providing a cooling surface for cooling a substrate in a vacuum chamber. According to this technique, since the substrate is cooled by the cooling surface provided on the side opposite to the evaporation source with respect to the substrate, the rise of the substrate temperature can be prevented.

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-248828

Patent Document 2: Japanese Patent Application Laid-Open No. 2008-184628

However, the technique disclosed in Patent Document 2 is a technique for forming a film by vacuum deposition on a substrate made of a material having a low thermal deformation temperature such as plastic, and a technique for manufacturing a semiconductor optical element, more specifically, There is no description of a technique for forming a high-performance reflective layer.

Therefore, using the technique disclosed in Patent Document 2, there has been a demand for a method for producing a high-performance semiconductor light emitting device substrate having a high reflectance of the reflective layer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a high performance semiconductor light emitting device substrate while reducing the manufacturing time in the method of manufacturing a semiconductor light emitting device substrate.

Further, another object of the present invention is to provide a method for manufacturing a semiconductor light emitting device substrate, which is intended to reduce the manufacturing cost of the semiconductor light emitting device substrate and has a low manufacturing cost.

According to the method for manufacturing a semiconductor light emitting device substrate of the present invention, the production of a semiconductor light emitting device substrate comprising a dielectric layer composed of two or more layers having different refractive indices and a reflective layer on one surface of the substrate in order. The method is carried out simultaneously with a substrate holding and holding step of holding and holding the substrate in a substrate holding and holding means disposed in the vacuum chamber, a vacuum exhausting step of evacuating the inside of the vacuum chamber, and a vacuum exhausting step thereof. A substrate heating step of heating the substrate, a substrate cleaning step of irradiating ions to the substrate to clean the substrate, a dielectric layer forming step of depositing the dielectric layer on the substrate, and stopping heating of the substrate The substrate heating stop step and cooling means arranged at a position where the substrate is not in contact with the substrate in the vicinity of the substrate. A cooling step of absorbing radiation heat from the substrate and the substrate holding and holding means to start cooling the substrate and the substrate holding and holding means, and a reflective layer forming step of depositing the reflective layer on the dielectric layer in this order; It is solved by doing.

In the conventional method, since the substrate is disposed in a vacuum, the substrate is vacuum-insulated, and as a result, a long time is required for cooling the substrate. In the dielectric layer forming step, since the evaporation source and the ion source are heated and the substrate receives the radiant heat, the cooling efficiency is very low.

With respect to such a problem, according to the method for manufacturing a semiconductor light emitting device substrate of the present invention, by absorbing the radiant heat from the substrate by the cooling means, it can be effectively cooled. Therefore, after forming a plurality of dielectric layers, even if the substrate temperature rises, by providing a cooling step for absorbing the radiant heat of the substrate in the vacuum chamber, the cooling time of the substrate can be shortened, and the manufacturing time can be shortened. have.

In addition, according to the method for manufacturing a semiconductor light emitting device substrate of the present invention, a semiconductor light emitting device comprising a dielectric layer composed of two or more layers having different refractive indices and a reflective layer on one surface of the substrate in order. A method of manufacturing a substrate, which is carried out simultaneously with a substrate holding and holding step of holding and holding the substrate in a substrate holding and holding means disposed in a vacuum chamber, a vacuum evacuating step of evacuating the inside of the vacuum chamber, and a vacuum exhausting step thereof. And a substrate heating step of heating the substrate, and cooling means disposed in a position in the vicinity of the substrate that is not in contact with the substrate, thereby absorbing radiant heat from the substrate and the substrate holding / holding means, thereby causing the substrate and A cooling step of starting cooling of the substrate holding and holding means, and irradiating ions to the substrate to clean the substrate; A plate cleaning step, a dielectric layer forming step of depositing the dielectric layer on the substrate, a substrate heating stop step of stopping heating of the substrate, and a reflective layer forming step of depositing the reflective layer on the dielectric layer, in this order. It is solved by doing.

As described above, in the present invention, prior to the dielectric layer forming step and further, the substrate cleaning step, there is provided a step of absorbing radiant heat from the substrate and the substrate holding and holding means by the cooling means to cool the substrate and the substrate holding and holding means. have. Therefore, during substrate cleaning, the substrate temperature does not increase excessively during the formation of the dielectric layer, so that the cooling time until the reflection layer forming process is started can be further shortened, and the manufacturing efficiency can be further improved.

In addition, since the substrate is also cooled in the process of forming a plurality of dielectric layers, a dielectric film having a good film quality can be formed.

At this time, before the substrate cleaning step, a first judgment step for determining whether the inside of the vacuum chamber is 1 × 10 ⁻³ Pa or less is further provided. When the inside of the vacuum chamber is 1 × 10 ⁻³ Pa or less, the substrate cleaning step is performed. desirable.

Thus, if the first judgment step is provided before the substrate cleaning step, the substrate cleaning step is performed when the vacuum chamber is 1 × 10 ⁻³ Pa or less, and further, the film formation of the dielectric layer is started following the substrate cleaning step. Dielectric layer can be formed, and as a result, high reflectance can be obtained by combining with the reflective layer. On the other hand, when the pressure in the vacuum chamber at the time of forming the dielectric layer is higher than 1 × 10 ⁻³ Pa, it is difficult to obtain a dielectric film of good quality, and when combined with the reflective layer, it is difficult to obtain a high reflectance.

Further, before the reflective layer forming step, a second judgment step of determining whether the temperature of the substrate is 50 ° C. or less and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less is further provided, and the temperature of the substrate is 50 ° C. or less. When the inside of a vacuum chamber is 3x10 <^-4> Pa or less, it is preferable to perform the said reflective layer forming process.

Thus, by providing a 2nd judgment process before a reflection layer forming process, and forming a reflective layer only when the temperature of a board | substrate is 50 degrees C or less and the inside of a vacuum chamber is 3x10 <^-4> Pa or less, it is high A reflective layer having a reflectance can be formed. On the other hand, when the substrate temperature is higher than 50 ° C. or when the pressure in the vacuum chamber during the reflective layer film formation is higher than 3 × 10 ⁻⁴ Pa, the reflectance of the reflective layer is low, and it is difficult to obtain a good reflective layer.

The reflective layer is preferably formed by depositing aluminum.

High reflectance can be obtained by using aluminum having high reflectance as the material of the reflecting layer. Moreover, it can be set as the reflective layer provided with high adhesiveness with respect to each dielectric layer.

The dielectric layer is preferably formed by alternately combining a layer having a high refractive index and a layer having a low refractive index.

By using the high refractive index dielectric material and the low refractive index dielectric material as the material of the dielectric layer, and depositing them alternately, higher reflectance can be obtained when combined with the reflective layer.

The second judging step includes a vacuum pump connected to the vacuum chamber via a vacuum valve, a pressure control means connected to the vacuum valve, a thermometer provided near the substrate, and a temperature connected to the cooling means. It is preferable that the reflection layer forming step is performed by the control means, and the shutter control means connected to the pressure control means and the temperature control means is performed by controlling to open the shutter disposed on the evaporation source.

In this manner, when the pressure in the vacuum chamber is monitored by the pressure control means, the vacuum valve is automatically opened and closed, and the pressure in the vacuum chamber is controlled so that the workability is improved and manufacturing efficiency can be improved.

In addition, when the substrate temperature is monitored by the temperature control means and the strength and weakness of the cooling power are controlled in the cooling means, the workability is improved and the production efficiency can be improved.

Then, when the pressure in the vacuum chamber and the substrate temperature are monitored by the respective control means, and the respective conditions are below a predetermined condition, the shutter is opened by the shutter control means connected to the pressure and temperature control means. Can be further improved. In addition, it is possible to manufacture a semiconductor light emitting device substrate under uniform conditions without forming a layer for each layer due to a mistake of each operator.

According to the method for manufacturing a semiconductor light emitting device substrate of claim 1, since the time for cooling the substrate is shortened before the film formation of the reflective layer is started, the production efficiency can be improved. In addition, by providing a pressure condition and a temperature condition suitable for forming the reflective layer and the dielectric layer, a semiconductor light emitting device substrate having high reflectance can be provided.

According to the method for manufacturing a semiconductor light emitting device substrate of claim 2, the substrate is cooled even when the substrate is cleaned or when the dielectric layer is formed, so that the time for cooling the substrate before the formation of the reflective layer is further shortened. In addition, by providing a pressure condition and a temperature condition suitable for forming the reflective layer and the dielectric layer, a semiconductor light emitting device substrate having high reflectance can be provided.

According to the method for manufacturing a semiconductor light emitting device substrate of claim 3, a good film quality dielectric layer can be formed.

According to the method for manufacturing a semiconductor light emitting device substrate of claim 4, a reflective film of good film quality can be formed.

According to the method for manufacturing a semiconductor light emitting element substrate of claim 5, by using aluminum as the material for forming the reflective layer, a reflective layer having a higher reflectance can be formed.

According to the method for manufacturing a semiconductor light emitting device substrate of claim 6, in each layer of the dielectric layer, the reflectance can be further improved by alternately combining a high refractive index layer and a low layer.

According to the method for manufacturing a semiconductor light emitting element substrate of claim 7, since the operator does not have to monitor or control the pressure in the vacuum chamber and monitor and control the substrate temperature, the work efficiency is improved. In addition, since the operator does not mistake the pressure in the vacuum chamber and the substrate temperature to start film formation of each layer, a semiconductor light emitting device substrate having a reflective layer and a dielectric layer of uniform quality can be manufactured.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the thin film forming apparatus of one Embodiment of this invention.
It is explanatory drawing which shows the thin film forming apparatus of other embodiment of this invention.
3 is a schematic cross-sectional view of a semiconductor light emitting element substrate of one embodiment of the present invention.
4 is a flowchart of a manufacturing process of the semiconductor light emitting element substrate according to the embodiment of the present invention.
5 is a flowchart of a manufacturing process of a semiconductor light emitting element substrate according to another embodiment of the present invention.
6 is a graph showing a relationship between a manufacturing time and a substrate temperature of a semiconductor light emitting device substrate according to the embodiment of the present invention.
7 is a graph showing the relationship between the wavelength and the reflectance of a reflective layer in which dielectrics having different refractive indices are laminated.
Explanation of the sign
1 ion assist deposition apparatus (thin film forming apparatus)
2 vacuum chambers
3 substrate holder (substrate holding and holding means)
3a through hole
3b mounting member
4 Substrate holder shaft
5 Substrate Holder Rotating Motor
6 evaporation source
7 ion source
8 Heating means
11 Freezers (cooling means)
12 Refrigerant line (cooling means)
13 Cooling plate (cooling means)
13a proximity cooling surface
17, 18 mounting jig
20 compressor
21 Cooling Solenoid Valve
22 cooling condenser
23 Thaw Solenoid Valve
24 Temperature control means
25 thermometer
26 heat exchanger
31 vacuum valve
32 pressure gauge
33 vacuum pump
34 pressure control means
43 Upper cooling plate (cooling means)
43a proximity cooling surface
44 Bottom cooling plate (cooling means)
44a Evaporation Source Cooling Surface
44b opening (evaporation source through opening)
44c opening (ion source through opening)
45 side cooling plate (cooling means
45a Sidewall Cooling Surface
46 refrigerant tube
100 buffer layer
110 n-type GaN layer
120 light emitting layer
130 p-type GaN layer
210 n electrode
230 p electrode
S board
P deposition material
R reflective layer
H high refractive index dielectric layer
L low refractive index dielectric layer

EMBODIMENT OF THE INVENTION Below, one Embodiment of this invention is described with reference to drawings. In addition, the member, arrangement | positioning, etc. which are demonstrated below do not limit this invention, Of course, it can be variously modified according to the meaning of this invention.

1 is an explanatory view of an ion assist vapor deposition apparatus 1 which is a kind of thin film forming apparatus, and shows a part of the apparatus as a cross section.

As shown in the figure, the ion assist deposition apparatus 1 includes a vacuum chamber 2, a substrate holder 3, a substrate holder rotation shaft 4, a substrate holder rotation motor 5, and an evaporation source 6 ), An ion source 7, a heating means 8, a refrigerator 11, a refrigerant pipe 12, and a cooling plate 13 as main components.

The vacuum chamber 2 is a container for film formation inside. In the vacuum chamber 2 of this embodiment, it becomes possible to form the thin film by arrange | positioning the board | substrate S with a substantially cylindrical hollow body. A vacuum pump 33 is connected to the vacuum chamber 2, and the vacuum pump 33 exhausts the interior of the vacuum chamber 2, so that the interior of the vacuum chamber 2 is 1 × 10 ⁻² to 1. It can be set to a vacuum of about 10 ^-5 Pa.

In the vacuum chamber 2, a gas introduction tube (not shown) for introducing gas into the vacuum chamber 2 is formed.

As a material of the vacuum chamber 2, metal materials, such as aluminum and stainless steel, etc. are mentioned. In this embodiment, SUS 304 which is a kind of stainless steel is used.

The substrate holder 3 is a member provided inside the vacuum chamber 2 to hold and hold the substrate S. As shown in FIG. Although the board | substrate holder 3 of this embodiment is comprised from the plate-shaped member, you may be comprised from the dome-shaped member which has a predetermined curvature. The substrate holder 3 corresponds to the substrate holding and holding means of the present invention.

The substrate holder 3 is formed with a through hole 3a penetrating from one plate surface to the other plate surface. The board | substrate S is attached to the board | substrate holder 3 using the mounting member 3b so that this through-hole 3a may be blocked.

The mounting member 3b of the present embodiment has a disk shape having a diameter larger than that of the through hole 3a of the substrate holder 3, and part of the disk surface is concave downward. An opening is formed in this recessed portion. The mounting of the substrate S into the substrate holder 3 first places the mounting member 3b in the through hole 3a of the substrate holder 3, and then the substrate S in the recess of the mounting member 3b. ), And put the film face down. Thus, in this embodiment, the board | substrate S can be set simply by simply mounting the mounting member 3b and the board | substrate S to the board | substrate holder 3. As shown in FIG. In addition, the substrate S may be fixed to the mounting member 3b so that the substrate S does not move when the substrate holder 3 is rotated.

One end side of the rod-shaped substrate holder rotation shaft 4 is connected to the center of the substrate holder 3 in a direction perpendicular to the plate surface of the substrate holder 3. The other end side of the substrate holder rotating shaft 4 penetrates through the wall surface of the vacuum chamber 2 to the outside of the vacuum chamber 2, and is connected to the output shaft of the substrate holder rotating motor 5.

The substrate holder rotating motor 5 is a device for rotating the substrate holder 3. The substrate holder rotary motor 5 is provided outside the vacuum chamber 2. The output shaft of the substrate holder rotary motor 5 coincides with the axis of the substrate holder rotary shaft 4 so that the rotational output of the substrate holder rotary motor 5 is transmitted to the substrate holder 3 via the substrate holder rotary shaft 4. It is transmitted and the substrate holder 3 rotates.

The output shaft of the substrate holder rotary motor 5 is vacuum-sealed by means such as a magnetic seal bearing (not shown).

The board | substrate S is a member used as the base on which each layer is formed in the surface. In the present invention, a sapphire substrate having high versatility is preferably used as the substrate S of the semiconductor light emitting device substrate. In addition, a material suitable for the material of the semiconductor light emitting device substrate can be used.

In addition, in this embodiment, although the flat form is used as a shape of the board | substrate S, it is not limited to this, The board | substrate with a suitable shape can be used as a board | substrate in which a semiconductor light emitting element substrate is formed.

The evaporation source 6 is disposed under the vacuum chamber 2 and is evaporated to release the deposition material P, that is, the high refractive index material, the low refractive index material, and the metal (Al, Ag, etc.) toward the substrate S. Means. The evaporation source 6 is provided with the evaporation boat provided in the upper part with the pan place for raising vapor deposition material P, and the electron gun which irradiates and vaporizes the vapor deposition material P with an electron beam. In addition, in this embodiment, the shutter which is not shown in figure is provided in the position which cuts off the vapor deposition material P toward the board | substrate S from an evaporation boat. And this shutter is suitably opened and closed controlled by the shutter control means which is not shown in figure.

In the present embodiment, a general apparatus used in the vapor deposition apparatus is employed as the evaporation source 6. That is, a plurality of cylindrical hearth liners are provided as evaporation boats, and these hearth liners are disposed in the concentric fan of the disc shaped hearth. The disk shaped hearth is formed of a metal with high thermal conductivity, such as copper, and is cooled directly or indirectly by the water cooling device which is not shown in figure. The vapor deposition material P is accommodated in each hearth liner, and when the vapor deposition material P of one hearth liner disappears, a disk shaped hearth rotates and the vapor deposition material P of the next hearth liner is evaporated.

Since the disk shaped hearth itself is water-cooled, it is difficult to become a heat source. However, since the vapor deposition material P remaining on the hearth liner is usually an oxide, the thermal conductivity is low and difficult to cool. For this reason, the vapor deposition material P on a hearth liner becomes a heat source which heats the board | substrate S by radiant heat.

In the state where the vapor deposition material P which becomes a raw material of a thin film on the evaporation boat is generated, when an electron beam of about 1-3 kW is generated and this is irradiated to the vapor deposition material P, the vapor deposition material P is heated and evaporates. When the shutter not shown in this state is opened, the vapor deposition material P evaporating from the evaporation boat moves inside the vacuum chamber 2 toward the substrate S, and adheres to the surface of the substrate S. FIG. During film formation, the temperature of the evaporation source 6 rises to 1500 to 2500 ° C.

In addition, since the evaporation source 6 is preheated even when the shutters other than the film formation are closed for melting of the vapor deposition material P, the shutter and the surrounding temperature also increase.

The evaporation source 6 is not limited to a device evaporated by the electron gun, and may be, for example, a device for evaporating the vapor deposition material P by resistance heating.

In the semiconductor optical element formed in this embodiment, a high refractive index material and a low refractive index material are laminated alternately, and a film is formed by further laminating a reflective layer R thereon (see Fig. 3). Depending on the kind and number, the number and arrangement of the evaporation sources 6 can be changed as appropriate.

The ion source 7 is a device for irradiating positive ions toward the substrate S. The ion source 7 is an ion charged from a plasma of a reaction gas (for example, O ₂ ) or an inert gas (rare gas) (for example, Ar). O ₂ ⁺ , Ar ⁺ ) are taken out, accelerated by the acceleration voltage, and ejected. As the ion source 7, a known one generally used in the vacuum deposition apparatus can be used.

The vapor deposition material P, which moves from the evaporation source 6 toward the substrate S, is firmly attached to the surface of the substrate S with high compactness by the collision energy of the cation irradiated from the ion source 7. . At this time, the substrate S is positively charged by the cation included in the ion beam.

If necessary, a neutralizer for neutralizing charges by irradiating an electron beam to the positively charged substrate S or the substrate holder 3 may be provided.

In addition, in this embodiment, after ion-cleaning the surface of the board | substrate S with the ion discharge | released from the ion source 7, each layer is formed.

In the present embodiment, the heating means 8 is provided below the substrate holder 3. The heating means 8 is a heating source for heating the substrate S by radiant heat. In addition, as such a heating means 8, well-known things, such as a halogen lamp and an infrared heater, are used. In addition, you may control the evaporation amount of the heating means 8 by the temperature control means 24 based on the temperature measured by the thermometer 25 mentioned later.

The pressure inside the vacuum chamber 2 is measured and displayed by the pressure gauge 32, and the desired pressure can be controlled by the pressure control means 34. That is, the internal pressure measured by the pressure gauge 32 is monitored by the pressure control means 34 connected to the pressure gauge 32, and when the pressure is lower than the predetermined pressure, the vacuum valve connected to the pressure control means 34 ( By closing 31, the evacuation by the vacuum pump 33 is not performed. In addition, it is good also as a structure provided with the MV (miniature valve) not shown in the vacuum chamber 2 side.

On the other hand, in the state which is not depressurized to the target pressure, the vacuum valve 31 connected to the pressure control means 34 opens, and the evacuation by the vacuum pump 33 is performed. In this way, the pressure inside the vacuum chamber 2 is monitored by the pressure control means 34, so that the pressure in the vacuum chamber 2 can be controlled to a predetermined value.

In the vacuum chamber 2, the portion where the pressure gauge 32 is disposed has a vacuum sealed configuration. In addition, a well-known thing can be used for the pressure gauge 32, the vacuum valve 31, and the vacuum pump 33, respectively.

Next, the cooling means of this embodiment is demonstrated.

The cooling means is a means for cooling the substrate S and maintaining the temperature at a suitable temperature. The cooling means has the refrigerator 11, the refrigerant pipe 12, and the cooling plate 13 as main components.

The cooling plate 13 is arrange | positioned inside the vacuum chamber 2. The cooling plate 13 has a disk shape and is disposed along the upper surface of the substrate holder 3. That is, the cooling plate 13 is arrange | positioned on the opposite side to the side where the evaporation source 6 is installed with the board | substrate holder 3 interposed. The cooling plate 13 is formed of metal material with high thermal conductivity, such as copper and aluminum.

In addition, in consideration of the temperature of the substrate holder 3, the substrate S, the performance of the refrigerator 11, and the like, the cooling plate 13 may be a plate-shaped or rectangular shape, which is perforated, instead of a complete plate shape.

The central axis of the vacuum chamber 2 of the cooling plate 13, that is, the surface on which the substrate S is disposed constitutes the near cooling surface 13a of the present invention. In addition, the coolant pipe 12 abuts the surface opposite to the near cooling surface 13a. For this reason, the surface which contacts the refrigerant pipe 12 of the cooling plates 13 is cooled by the refrigerant | coolant which flows through the refrigerant pipe 12, and the near cooling surface 13a formed in the surface opposite to this is also cooled.

The cooling plate 13 is fixed in the vacuum chamber 2 using the mounting jig 17. A gap is formed between the cooling plate 13 and the substrate holder rotation shaft 4 so that the substrate holder rotation shaft 4 can rotate smoothly. In addition, in order to prevent heat from being introduced into the heat conduction from the substrate holder rotation shaft 4, a material having low thermal conductivity is sandwiched between the substrate holder rotation shaft 4 and thermally insulated, or a cooling plate for cooling the substrate holder rotation shaft 4 is provided. You may arrange.

In addition, a bearing or the like is provided between the wall surface of the cooling plate 13 and the outer circumferential surface of the substrate holder rotation shaft 4 to smoothly rotate the substrate holder rotation shaft 4 and generate heat movement along the substrate holder rotation shaft 4. You may make it difficult to do it.

The refrigerant pipe 12 is comprised by the tubular member which is hollow inside, and has a role as a cryo coil which cools the cooling plate 13 mentioned later. One end of the refrigerant pipe 12 is connected to the discharge port of the refrigerator 11 and the other end is connected to the inlet port, and is introduced into the vacuum chamber 2. And the refrigerant | coolant discharged from the refrigerator 11 flows from one end side to the other end side, and is comprised so that the refrigerant | coolant may be circulated to the refrigerator 11.

The refrigerant pipe 12 is spirally wound so that the refrigerant inflow side is on the outside and the delivery side is on the inside, and is fixed to abut the outer plane of the disk-shaped cooling plate 13. Moreover, the form which fixes the refrigerant pipe 12 is not limited to such a vortex shape, but may be a spiral shape, a zigzag shape, etc. may be sufficient as it.

The refrigerator 11 is an apparatus for cooling a refrigerant | coolant and supplying it to the refrigerant pipe 12 for circulation. The refrigerator 11 of this embodiment uses the well-known refrigeration apparatus which makes the refrigerant pipe 12 the cryo coil.

Specifically, the refrigerator 11 includes a compressor 20 for compressing a refrigerant (gas refrigerant), a water cooling condenser 22 for cooling the refrigerant from the compressor 20 by heat exchange with cooling water, and compressed water cooling. And a cooling solenoid valve 21 and a thawing solenoid valve 23 provided on the discharge port side of the refrigerator 11 to expand and cool the refrigerant. An expansion valve (not shown) is provided inside the heat exchanger 26.

And the coolant pipe 12 as a cryo coil is cooled by flowing the coolant cooled by the refrigerator 11 to the coolant pipe 12. The refrigerant in the refrigerant pipe 12 rises in temperature in the vacuum chamber 2 to partially evaporate, and is refluxed to the refrigerator 11 as a gas refrigerant having a high temperature. The gas refrigerant is compressed by the compressor 20 and cooled again by the water cooling condenser 22 and the heat exchanger 26 to form a low temperature refrigerant, and is again sent out from the discharge port to the refrigerant pipe 12.

The refrigerator 11 is provided with an inlet for introducing a gas refrigerant circulated through the refrigerant pipe 12. The high temperature gas refrigerant introduced from the inlet port is cooled again in the refrigerator 11.

In addition, by closing the cooling solenoid valve 21 and opening the thawing solenoid valve 23, the gas refrigerant (hereinafter referred to as "heating gas") compressed by the compressor 20 and having a relatively high temperature is a water cooling condenser ( By flowing directly into the refrigerant pipe 12 without passing 22), the temperature of the cryocoil can be rapidly increased to about room temperature.

On the discharge port side of the refrigerator 11, a cooling solenoid valve 21 and a thawing solenoid valve 23 are provided. Each solenoid valve 21 and 23 is equipped with two valves, and is a valve which can switch this by electronic control.

The cooling solenoid valve 21 is provided in the middle of the line for supplying the refrigerant from the heat exchanger 26 to the refrigerant pipe 12. Moreover, the thawing solenoid valve 23 is provided in the middle of the branch line branched from the said line and connected to the output side line of the compressor 20.

The freezer 11 can take three modes. That is, both the solenoid valves 21 and 23 are closed, and the "standby mode" in which neither the refrigerant nor the heating gas is supplied to the refrigerant pipe 12, and only the cooling solenoid valve 21 is opened to supply the refrigerant to the refrigerant pipe 12. Only the "cooling mode" and the thawing solenoid valve 23 are open, and the "thawing mode" in which heating gas is supplied to the refrigerant pipe 12.

Before the start of cooling, the mode of the refrigerator 11 is set to "standby mode", and both the cooling solenoid valve 21 and the thawing solenoid valve 23 are in a closed state.

When the cooling plate 13 is cooled by the refrigerator 11, the mode of the refrigerator 11 is set to "cooling mode", the cooling solenoid valve 21 is opened, and the thawing solenoid valve 23 is closed. . As a result, for example, the coolant cooled to -100 ° C or lower flows into the coolant tube 12, and the cooling plate 13 is cooled to -100 ° C or lower.

On the other hand, when opening the ion assist vapor deposition apparatus 1 to air | atmosphere, since the temperature of the cooling plate 13 needs to be about 0 degreeC or more, the mode of the refrigerator 11 is made into "thawing mode", and it cools down. The solenoid valve 21 is closed and the thawing solenoid valve 23 is opened. Thereby, heating gas is supplied to the refrigerant pipe 12, and the temperature of the cooling plate 13 rises.

The thermometer 25 for measuring the temperature of the board | substrate S is arrange | positioned near the board | substrate S. FIG. The thermometer 25 can use well-known temperature measuring means, such as a thermocouple.

The thermometer 25 is connected to the temperature control means 24. The temperature control means 24 is also connected to a solenoid valve for controlling the opening and closing of the cooling solenoid valve 21 and the thawing solenoid valve 23 of the refrigerator 11, and by appropriately changing the opening and closing states of the cooling plate ( The cooling temperature of the board | substrate S by 13) is adjusted.

With this configuration, the temperature can be kept constant by changing the supply power in accordance with the film formation conditions during the film formation.

The refrigerator 11 can implement any one of a "standby mode", a "cooling mode", and a "thawing mode" according to the operation state of the apparatus. The temperature of the cooling plate 13 can be measured by detecting the temperature of the refrigerant returning to the freezer 11 with a thermometer (not shown) provided in the freezer 11. Based on the cooling plate temperature set previously, the operation state of the refrigerator in a "cooling mode" can be controlled, and the temperature of the cooling plate 13 can be controlled.

Since the near cooling surface 13a is provided at a position close to the substrate S, it absorbs the radiant heat from the substrate S and the substrate holder 3 and cools it. That is, since the amount of heat radiated from the substrate S and the substrate holder 3 having a high temperature is larger than the amount of heat radiated from the near-cooling surface 13a having a low temperature, the heat from the substrate S and the substrate holder 3 is closer. Radiation cooling takes place as the heat moves to the cooling surface 13a, whereby the substrate S and the substrate holder 3 are cooled.

By providing such a structure, the cooling plate 13 becomes possible to cool the board | substrate S from the upper side of the board | substrate holder 3. As shown in FIG. For this reason, it becomes possible to suppress the temperature rise of the board | substrate S, and to maintain the target board | substrate temperature at the time of film-forming. In addition, even when the substrate temperature rises during film formation, the substrate S is cooled, so that the cooling time can be shortened effectively.

Moreover, since the board | substrate S is mounted on the mounting member 3b and is attached to the board | substrate holder 3, the upper and lower surfaces of the board | substrate S are exposed to the outside, and the exposed surface of the board | substrate S and the near cooling surface ( 13a) There is nothing which shields between. For this reason, radiant heat moves smoothly from the board | substrate S to the proximity cooling surface 13a, and it becomes possible to cool the board | substrate S efficiently.

In addition, in order to cool the board | substrate S uniformly, you may cover the whole surface of the board | substrate S with the coating member formed from substantially the same material as the board | substrate holder 3. As shown in FIG. In this case, it is preferable that the covering member and the substrate holder 3 have almost the same heat radiation rate, and that the total heat capacity of the sum of the heat capacities of the substrate S and the covering member is approximately the same as that of the substrate holder 3.

Next, the movement of heat in the vacuum chamber 2 of FIG. 1 is demonstrated.

Since the cooling plate 13 and the substrate holder 3 are provided in close proximity, the cooling plate 13 and the substrate holder 3 may be regarded as substantially parallel flat plates. Heat transfer by radiant heat per unit area of a parallel plate is represented by the following formula | equation (3).

Q = εsσT _s ⁴ −εcσT _c ⁴ . (Equation 3)

Where Q is the heat, εs is the thermal radiation rate of the substrate S, εc is the thermal radiation rate of the cooling plate 13, σ is the Stefan-Boltzmann constant, Ts is the absolute temperature [K] of the substrate S, and Tc is cooling It is the absolute temperature [K] of the plate 13.

Since εs and εc are the same order, if Tc is sufficiently low compared to Ts, heat flows unilaterally from the substrate S to the cooling plate 13. This effect is, for example, when Ts is 100 ° C., the cooling effect is about 1 kW per 1 m 2 of one side of the cooling plate 13, and the substrate S is compared with the case where there is no cooling plate 13. The temperature of) can be lowered by 30 ° C or more. Since the cooling plate 13 absorbs heat from both the upper and lower sides, the cooling plate 13 may have a cooling capacity of about 2 kW.

Since the evaporation source 6 becomes 1 to 3 kW and the ion source 7 becomes a heat source of 0.5 to 1.5 kW, when the cooling effect is insufficient only by the cooling plate 13 (the upper cooling plate 43 of FIG. 2), By providing the bottom cooling plate 44 and the side cooling plate 45 like other embodiment shown in FIG. 2, the temperature of the board | substrate S can be reduced more effectively.

Next, with reference to FIG. 2, the thin film forming apparatus of other embodiment of this invention is demonstrated. 2 is an explanatory diagram of a thin film forming apparatus 1 of another embodiment of the present invention.

The thin film forming apparatus (ion assist deposition apparatus) 1 of the present embodiment has a bottom cooling plate 44 and side cooling, in addition to a cooling plate (upper cooling plate 43) provided on the upper surface side of the substrate holder 3. The board 45 is provided, and the board | substrate 3 is characterized by surrounding the whole periphery of the board | substrate with a cooling plate.

Inside the vacuum chamber 2, an upper cooling plate 43 disposed on the opposite side of the evaporation source 6 with the substrate holder 3 interposed therebetween and disposed near the substrate holder 3, and the vacuum chamber 2. The main components are the bottom part cooling plate 44 arrange | positioned at the bottom part of the side, and the side part cooling plate 45 arrange | positioned along the inner surface of the vacuum chamber 2 as a main component.

Among these, since the upper cooling plate 43 is the same structure as the cooling plate 13 of 1st Embodiment, description is abbreviate | omitted. That is, the upper cooling plate 43 constitutes a part of the cooling means of the present invention, and the side surface of the substrate holder 3 forms the proximity cooling surface 43a.

The bottom cooling plate 44 constitutes part of the cooling means of the present invention, and the substrate holder 3 side surface constitutes the evaporation source side cooling surface 44a. The side cooling plate 45 constitutes a part of the cooling means of the present invention, and the substrate holder 3 side surface constitutes the side wall side cooling surface 45a. In addition, the refrigerator 11 and the refrigerant pipe 12 correspond to the cooling means of this invention.

An opening 44b (evaporation source through opening) for penetrating the evaporation source 6 and an opening 44c (ion source through opening) for penetrating the ion source 7 are formed in the bottom cooling plate 44. have. The evaporation source 6 is located in the area surrounded by the cooling plate 13 at each upper side through the opening 44b and the ion source 7 through the opening 44c. As described above, the bottom cooling plate 44 includes openings 44b and 44c, thereby obstructing the deposition material P or the ion beam supplied from the evaporation source 6 or the ion source 7 to the substrate S. It does not have a shape.

The side cooling plate 45 is detachably attached to the side inner wall surface of the vacuum chamber 2. The side cooling plate 45 also serves as a protective plate. That is, the side cooling plate 45 has a function as a member which prevents the deposition material P from the evaporation source 6 from adhering to the side inner wall surface of the vacuum chamber 2.

When the vapor deposition material P adheres to the side cooling plate 45 and the vacuum chamber 2 is contaminated, the side cooling plate 45 is removed from the vacuum chamber 2 and the surface is sandblasted or the like. It is possible to remove the deposition material P by polishing the. Thereby, the inside of the vacuum chamber 2 can be made into the clean state.

In addition, like the side cooling plate 45, the bottom cooling plate 44 also has a function of attaching and detaching and having a function as an anti-deposition plate.

The coolant pipe 46 abuts on the wall surface side of the vacuum chamber 2 of the upper cooling plate 43, the bottom cooling plate 44, and the side cooling plate 45. The coolant pipe 46 is a tubular member capable of flowing a coolant therein, similarly to the coolant pipe 12 of the first embodiment.

The coolant pipe 46 is spirally wound in the upper plane of the upper cooling plate 43, and then the outer peripheral surface of the side cooling plate 45 is spirally wound to form a bottom cooling plate 44. It is wound in a spiral from the lower plane of the plane. The discharge port side of the refrigerator 11 is connected to one end of the upper cooling plate 43, and the inlet port side is fixed to one end of the bottom cooling plate 44. For this reason, the refrigerant supplied from the refrigerator 11 sequentially circulates through the upper cooling plate 43, the side cooling plate 45, and the bottom cooling plate 44, and returns to the refrigerator 11 again.

In the present embodiment, the upper cooling plate 43, the bottom cooling plate 44, and the side cooling plate 45 are configured to surround the entire circumference of the substrate holder 3. That is, since the heat from the evaporation source 6 and the ion source 7 is absorbed by the bottom cooling plate 44 and the side cooling plate 45, and the radiant heat from the substrate holder 3 is also absorbed, Compared with the above embodiment in which the cooling plate 13 is provided only above the substrate S, the substrate S can be cooled more reliably.

The bottom cooling plate 44 and the side cooling plate 45 are both optional components of the present invention. The bottom cooling plate 44 and the side cooling plate 45 have a special refrigerant depending on the heat resistance temperature of the substrate S and the deposition conditions (input power condition to the electron gun or the ion source 7, the deposition time, etc.). The water may be simply cooled by circulating water without cooling. In addition, when the board | substrate S can fully be cooled only by the upper cooling plate 43, it is not necessary to perform cooling by these bottom cooling plate 44 and the side cooling plate 45. FIG.

In addition, in this embodiment, the refrigerator 11 which cools the upper side cooling plate 43, the bottom side cooling plate 44, and the side side cooling plate 45 is a common apparatus, but each cooling plate 43-45 is used. You may provide an individual refrigerator for cooling.

Next, the structure of the semiconductor light emitting element substrate of one Embodiment of this invention is demonstrated using FIG. 3 is a schematic cross-sectional view of a semiconductor light emitting element substrate of one embodiment of the present invention.

In general, as shown in FIG. 3, in the semiconductor light emitting device, the buffer layer 100, the n-type GaN layer 110, the light-emitting layer 120, and the p-type GaN layer 130 are formed on a substrate S made of sapphire or the like. Are stacked in order. A portion of the n-type GaN layer 110 is removed in a step shape by etching, and an n electrode 210 is formed on the removed portion. In addition, the p electrode 230 is formed on the p-type GaN layer 130.

On the other hand, in the board | substrate S, each dielectric layer H and L and the reflection layer R correspond to a thickened reflection layer are provided on the surface on the opposite side to the surface in which each layer containing the light emitting layer 120 was provided.

Hereinafter, the reflection layer R side in the substrate S of the semiconductor light emitting element substrate of the embodiment of the present invention will be described.

Each of the dielectric layers H and L is alternately stacked on the substrate S with a high refractive index dielectric layer H and a low refractive index dielectric layer L. As shown in FIG. In FIG. 3, although the structure which laminated | stacked four dielectric layers H and L in total was shown in order from the high refractive index dielectric layer H on the board | substrate S, how many layers each layer may be provided and the refractive index What is necessary is just the structure which combined the film which becomes this relatively high substance and low substance alternately.

As a material forming the high refractive index dielectric layer (H), for example, titanium oxide (TiO ₂ , refractive index is 2.52), zirconium oxide (ZrO ₂ , refractive index is 2.4), tantalum oxide (Ta ₂ O ₅ , refractive index is 2.16) , Niobium oxide (Nb ₂ O ₅ , refractive index is 2.33). Further, as a material for forming the low refractive index dielectric layer L, for example, aluminum oxide (Al ₂ O ₃ , refractive index is 1.76), silicon oxide (SiO ₂ , refractive index is 1.45), magnesium fluoride (MgF ₂ , refractive index) Is 1.37).

After each of the dielectric layers H and L of the above configuration is formed, the reflective layer R is formed. The reflective layer R is formed of a metal having high reflectance, for example, aluminum (Al), silver (Ag), or the like is used. When Al is used as the material of the reflective layer R, the substrate temperature at the time of film formation and the pressure in the vacuum chamber 2 are largely related to the reflectance.

Each of these dielectric layers H, L and reflective layer R is formed by depositing various materials using the thin film forming apparatus 1 described above. In addition, each film thickness is suitably designed according to the desired reflectance. In addition, when forming each dielectric layer H and L, after setting the pressure in the vacuum chamber 2 to 1x10 <^-3> Pa or less, More preferably, it is about 1x10 <^-4> -1 * 10 <^-3> Pa, Dielectric layers H and L are formed. When forming the dielectric layers H and L, when the films are formed under a pressure higher than 1 × 10 ⁻³ Pa, it is difficult to obtain the dielectric layers H and L of good film quality. At this time, the temperature of the substrate S is preferably 100 to 120 ° C, preferably about 110 ° C, because the packing density of each dielectric layer H, L is high.

When forming the reflective layer R using Al on each dielectric layer H and L, the film is formed with a substrate temperature of 50 ° C. or lower and a pressure in the vacuum chamber 2 of 3 × 10 ⁻⁴ Pa or lower. . Thus, when forming the reflective layer R using Al, when the temperature of the board | substrate S is 70 degreeC from about room temperature (25 degreeC), more preferably 25 degreeC-50 degreeC, the reflective layer of favorable reflectivity ( R) can be obtained. In addition, when forming the reflective layer R, when the pressure in the vacuum chamber 2 in which the board | substrate S is arrange | positioned is about 1 * 10 <^-4> Pa-3 * 10 <^-4> Pa, the reflective layer R of favorable reflectance will be made You can get it.

On the other hand, when the substrate temperature is higher than 70 ° C. or when the breakdown voltage is higher than 3 × 10 ⁻⁴ Pa, it is difficult to obtain the reflective layer R having a good reflectance.

In FIG. 3, the buffer layer 100, the n-type GaN layer 110, the light emitting layer 120, and the p-type GaN layer 130 are sequentially stacked on the substrate S, and the reflective layer is opposite to these semiconductor layers. Although the example which formed (R) was shown, the structure of a semiconductor layer is not limited to this. It goes without saying that a semiconductor layer made of another material may be provided in a configuration different from that of FIG. 3 as long as it is a configuration that functions as a semiconductor light emitting element.

Next, a film formation process for forming each of the dielectric layers H and L and the reflective layer R having the above structure using the thin film forming apparatus 1 of the present embodiment will be described with reference to FIGS. 4 and 5. In addition, although the order of each process differs in FIG.4 and FIG.5, it selects suitably according to the material, film thickness, etc. of each dielectric layer (H, L).

First, the manufacturing process of the semiconductor light emitting element substrate of one Embodiment of this invention is demonstrated with reference to FIG. 4 is a flowchart of a manufacturing process of the semiconductor light emitting element substrate according to the embodiment of the present invention.

In this manufacturing process, first, the board | substrate S (refer FIG. 3) is set to the board | substrate holder 3 with the surface in which the reflective layer R is formed facing down, and the door of the vacuum chamber 2 is closed ( Substrate holding and holding step (S1)). Next, the vacuum valve 31 is opened to perform vacuum evacuation of the vacuum chamber 2 (vacuum evacuation step S2). In addition, this operation may be performed by the pressure control means 34.

In the board | substrate holding and holding process S1, the board | substrate S is set to the board | substrate holder 3 facing the surface on which the reflective layer R is formed to the evaporation source 6 side. More specifically, the buffer layer 100, the n-type GaN layer 110, the light emitting layer 120, and the p-type GaN layer 130 are stacked in this order, and the substrate S on which the electrodes 210 and 230 are formed ( 3) is set in the substrate holder 3 with the surface on which each semiconductor layer is not formed facing down.

Moreover, regarding the film-forming of each semiconductor layer, the process of forming each semiconductor layer on one surface of the board | substrate S before the board | substrate holding | maintenance process S1 is provided, or each semiconductor layer after the reflective layer formation process S10. You may be provided with the process of forming the structure. However, in general, film formation of each semiconductor layer made of a GaN-based compound requires excessive conditions, so that after forming each semiconductor layer on the substrate S in advance, each semiconductor layer is formed on the back surface of each semiconductor layer. It is preferable to perform the steps of forming the dielectric layers H and L and the reflective layer R. FIG.

After setting the inside of the vacuum chamber 2 to a reduced pressure state, heating by the heating means 8 is started so that the board | substrate S may be set temperature (110 degreeC in this embodiment), and the temperature control means 24 The temperature of the substrate S is adjusted to be the set temperature (substrate heating step S3). At this time, it is preferable that the heating means 8 is also connected to the temperature control means 24. The substrate S may be controlled so that the temperature of the substrate S becomes the set temperature until the dielectric layer forming step S7 is started.

Thus, when film-forming is performed in the state which heated the board | substrate S and hold | maintained at fixed temperature, since the packing density becomes high about the film formed on the board | substrate S, it is preferable.

Then, the pressure in the vacuum chamber 2 was measured and displayed by the pressure gauge 32, and it is judged whether the pressure control means 34 became 1x10 <^-3> Pa or less (1st determination process S4). .

In the first judging step S4, when the pressure in the vacuum chamber 2 does not reach 1 × 10 ⁻³ Pa or less (first judging step S4: No), the vacuum valve 31 continues. It is maintained in the open state, and exhaust is continued by the vacuum pump 33.

On the other hand, when the pressure in the vacuum chamber 2 reaches 1x10 <^-3> Pa or less (1st judgment process S4: Yes), the vacuum valve 31 will be opened and closed appropriately by the pressure control means 34. In addition, the displacement by the vacuum pump 33 is controlled, and the inside of the vacuum chamber 2 is maintained at 1x10 <^-3> Pa or less. In addition, even when the vacuum chamber 2 reaches a predetermined pressure (first determination step S4: Yes), the vacuum valve 31 and the MV (miniature valve) (not shown) are kept open and evacuated. It is preferable if is continued.

After the inside of the vacuum chamber 2 is maintained at 1 × 10 ^-3 Pa or less, the substrate holder (substrate holding / holding means) 3 holding and holding the substrate S rotates (substrate holding / holding means rotating step). (S5)), the ion beam is irradiated to the substrate S from the ion source 7. By irradiating the ion beam to the substrate S, contaminants adhering to the surface of the substrate S, in particular, hydrocarbon-based polymers and the like can be effectively removed (substrate cleaning step S6). In addition, the board | substrate holding | maintenance means rotation process S5 does not necessarily need to be performed in this order, but is provided before and after another process suitably.

After cleaning the surface of the substrate S, the dielectric layers H and L having the above structure are formed by vapor deposition (dielectric layer forming step S7). In the dielectric layer forming step S7, a shutter provided near the evaporation source 6 that emits a high refractive index material (for example, Ta ₂ O ₅ , TiO _2, etc.) or a low refractive index material (for example, SiO _2, etc.). By controlling the opening and closing of (not shown), the high refractive index material and the low refractive index material are alternately discharged toward the substrate S.

During the release of these deposition materials P, each dielectric layer adhered to the substrate S by impinging ions (for example, O ₂ ⁺ or Ar ⁺ ) from the ion source 7 onto the substrate S ( The surfaces of H and L) are smoothed and densified. This operation is repeated a predetermined number of times to form a multilayer film.

At this time, charge bias occurs in the substrate S due to the irradiation of the ion beam, but the bias of the charge is preferably configured to be neutralized by irradiating electrons toward the substrate S from a neutralizer (not shown).

Thereafter, the heating of the substrate S is terminated, and operation is started with the refrigerator 11 that has been operated in the standby mode in the cooling mode in advance, and cooling is started (cooling step S9). After ion cleaning (substrate cleaning step S6) and film formation of each dielectric layer H, L (dielectric layer forming step S7), the substrate S is at a high temperature of 100 ° C or higher. Therefore, by providing the substrate heating stop step (S8) and the cooling step (S9) for stopping the heating of the substrate (S), and cooling the substrate (S) by using the cooling means (11, 12, 13), Cooling can be performed quickly to the substrate temperature suitable for forming the reflective layer R to be performed next. In addition, although the order of board | substrate heating stop process S8 and cooling process S9 may be any one in FIG. 4, in order to suppress electric power consumption, it is preferable if substrate heating stop process S8 is performed first.

In addition, cooling of the board | substrate S is performed until the reflection layer formation process S11 is complete | finished. In this way, it is preferable that the reflective layer R is formed while cooling can form the reflective layer R having a higher reflectance.

And the temperature of the board | substrate S is measured by the thermometer 25, and it is judged by the temperature control means 24 whether board | substrate temperature became 50 degrees C or less (2nd judgment process S10). In addition, even when the substrate temperature is 50 ° C. or less, it is determined in the pressure control means 34 whether or not the pressure in the vacuum chamber 2 is 3 × 10 ⁻⁴ Pa or less (second determination step S10). ), Only when both of the substrate temperature and the breakdown voltage condition are satisfied, the process proceeds to the next step (second judgment step S10: Yes).

At this time, it is preferable to set it as the structure which determines whether the predetermined temperature (50 degreeC in this embodiment) is previously input to the temperature control means 24, and became below predetermined temperature. In addition, predetermined pressure (1 * 10 <^-3> Pa and 3 * 10 <^-4> Pa in this embodiment) is input in advance to the pressure control means 34, and the predetermined pressure or less in each determination process S4, S10 is carried out. It is preferable that it is a structure which judges whether it was.

When the substrate temperature does not reach 50 degrees C or less (2nd judgment process S10: No), it is difficult to obtain a favorable reflectance in the reflection layer R. FIG. Therefore, cooling of the board | substrate S is continued and the determination of the process S10 is repeated. In addition, when the inside of the vacuum chamber 2 does not reach 3x10 <^-4> Pa or less (2nd judgment process S10: No), it is difficult to obtain favorable reflectance in the reflection layer R. FIG. Therefore, even if the vacuum valve 31 or the MV (not shown) is opened between the reflective layer forming steps S11, vacuum evacuation is continued, and the pressure in the vacuum chamber 2 is maintained at 3 × 10 ^-4 Pa or less. As a result, a reflective film R having a good film quality is formed.

In the second judgment step S10, only when both the substrate temperature and the breakdown voltage condition are satisfied, the reflective layer R is formed on each dielectric layer H and L (reflection layer forming step S11). At this time, the temperature control means 24 and the pressure control means 34 and the shutter control means for controlling the opening / closing state of the shutter (not shown) provided on the evaporation source 6 were connected to each other to satisfy the two conditions. The shutter may be automatically opened at the time, and the reflective layer R may be formed. After the reflection layer R reaches the predetermined film thickness, a shutter (not shown) is closed, and the substrate S is appropriately cooled by a cooling mechanism, and the film forming operation is completed. Moreover, you may provide the process of forming a protective film further after film-forming of the reflective layer R formed of aluminum etc.

When the film forming operation is completed through the above process, the refrigerator 11 is operated in the thawing mode, and the temperature of the cooling plate 13 is raised to room temperature. Thereafter, a leak valve (not shown) is opened to introduce an inert gas or the like to make the inside of the vacuum chamber 2 atmospheric pressure (leak step S12). Then, the substrate S is taken out from the substrate holder 3. Further, in the leak step S12, the cooling plate 13 (each cooling) directly from the compressor 20 without passing the gas refrigerant circulating in the cooling means 11, 12, 13 through the heat exchanger 26. By flowing through the plates 43 to 45, it is possible to return the cooling plate to room temperature.

Through the above steps, the dielectric layers H and L and the reflective layer R of the semiconductor light emitting element substrate of the present invention are formed. In the above process, the description of the process of disposing a material deposited on the substrate S, that is, a material material of each of the dielectric layers H and L and the reflective layer R is omitted. 3) is appropriately performed before and after the mounting.

In addition, it is preferable to provide the preheating process of the evaporation source 6 and the ion source 7 suitably before the board | substrate washing | cleaning process S6 which performs ion cleaning.

Next, with reference to FIG. 5, the manufacturing process of the semiconductor light emitting element board | substrate of other embodiment of this invention is demonstrated. 5 is a flowchart of a manufacturing process of a semiconductor light emitting element substrate according to another embodiment of the present invention. Since the board | substrate holding and holding process S1 in FIG. 4 to 1st judgment process S3, and the board | substrate holding and holding process S101 shown in FIG. 5 to the board | substrate heating process S103 are the same structure, it demonstrates Omit.

As for the manufacturing process of the semiconductor light emitting element substrate shown in FIG. 5, after the substrate heating process S103 which starts heating of the board | substrate S, the cooling process S104 which starts cooling of the board | substrate S is performed. The operation of the refrigerator 11 at this time is the same as the cooling step (S9) of FIG.

Thus, unlike the manufacturing process of the semiconductor light emitting element substrate shown in FIG. 4, by providing the cooling process S104 at an early stage, the power consumption increases, but the cooling means 11, 12, 13 (and 43, 44)) can be operated stably, and since the cooling means 11, 12, 13 (and 43, 44) are operated in advance, the cooling time of the substrate S can be shortened. Can be.

After cooling of the board | substrate S is started in cooling process S104, it is determined in the 1st judgment process S105 whether the inside of the vacuum chamber 2 is 1x10 <^-3> Pa or less (1st judgment process S105). )). In this first determination step S105, after the inside of the vacuum chamber 2 is determined to be 1 × 10 ⁻³ Pa or less, in the present embodiment, each dielectric layer H, L is formed. In the first judgment step S105, it is also determined whether or not the temperature of the substrate S is maintained at the set temperature (about 110 ° C in the present embodiment), and the substrate temperature is maintained at the predetermined temperature. After the determination, it is preferable to proceed to the next step.

Subsequently, the substrate holder (substrate holding / holding means 3) holding and holding the substrate S rotates (substrate holding / holding means rotating step S106), and the ion source 7 with respect to the substrate S. ) Is irradiated (substrate cleaning step (S107)). As described above, if the substrate S is cooled by the refrigerator 11 even during ion cleaning of the substrate S, the temperature of the substrate S does not rise excessively, and thus the cooling time can be shortened. In addition, the board | substrate holding | maintenance means rotation process S106 does not necessarily need to be performed in this order, but is provided before and after another process suitably.

The substrate S is also cooled during the substrate cleaning step S107. However, since the substrate S is heated and maintained at about 110 ° C, in the following dielectric layer forming step S108, each dielectric layer H , L) can form a good film quality layer. In addition, since the substrate S is cooled during the dielectric layer forming step S108, the temperature of the substrate S does not rise too much even when the respective dielectric layers H and L are formed. The cooling time during film formation is very short.

As shown in Fig. 7, each of the dielectric layers H and L has a high number of layers, and a high reflectance can be obtained in the reflective layer R. However, when the number of layers is large, the substrate temperature is likely to increase. Therefore, as shown in Fig. 5, before the dielectric layer forming step (S108) for forming each dielectric layer (H, L), a cooling step (S104) for starting cooling of the substrate (S) is performed, whereby each dielectric layer (H, L) is formed. Even when the number of is relatively large, the rise of the substrate temperature can be prevented.

In addition, about cooling process S104, cooling may cool the board | substrate S until the film-forming of the reflective layer R is started, and you may cool until completion | finish of film-forming of the reflective layer R. FIG. By continuing cooling until the film formation of the reflective layer R is completed, the reflective layer R having a good film quality can be formed.

Therefore, according to the method for manufacturing a semiconductor light emitting device substrate of the present invention, even when the reflectance is improved by increasing the number of the dielectric layers H and L, the dielectric layers H and L and the reflective layer R are formed in a short time. can do.

Thus, after each dielectric layer H and L is formed in dielectric layer formation process S108, it progresses to the substrate heating stop process S109 which stops heating of the board | substrate S. As shown to FIG. It is preferable that the substrate heating stop step (S109) be performed by the temperature control means 24. After the substrate heating is stopped, the substrate holding / holding means rotation step (S106) and the substrate cleaning step (S107) may be performed. The flow proceeds to the second determination step S110. Since the process after the 2nd determination process S110 shown in FIG. 5, and the process after the 2nd determination process S10 in FIG. 4 are the same structure, the description is abbreviate | omitted.

Next, an embodiment of the present invention will be described with reference to FIG. 6 is a graph showing the relationship between the manufacturing time and the substrate temperature of the semiconductor light emitting element substrate of the embodiment of the present invention. In addition, the structure of each dielectric layer H, L, and the reflection layer R of the semiconductor light emitting element substrate of a present Example is the structure shown by the said FIG. In addition, each of the dielectric layers H and L and the reflective layer R of the semiconductor light emitting element substrate of this embodiment uses the thin film forming apparatus 1 described with reference to FIG. 1 above, and uses the manufacturing process described with reference to FIG. 4. After the film was formed.

In the present Example, each dielectric layer H and L was formed into a film on condition of the following.

Substrate: Sapphire Substrate

High refractive index dielectric material: TiO ₂ (refractive index: 2.52),

Low refractive index dielectric material: SiO ₂ (refractive index: 1.45)

Deposition rate of TiO ₂ : 0.5 nm / sec

Deposition rate of SiO ₂ : 1.0 nm / sec

Ion Source Conditions During TiO ₂ / SiO ₂ Evaporation

Inlet gas: Oxygen 60 sccm

Ion Acceleration Voltage: 1200 V

Ion Current: 1200 mA

Ion beam energy density: 100 mW / ㎠

Neutralizer Conditions

Neutralizer Current: 2000 mA

Discharge gas: Argon 10 sccm

In FIG. 6, the horizontal axis shows the substrate S by the heating means 8 in FIG. 2 after the substrate S is placed on the substrate holder 3 (that is, the substrate holding and holding step S1 of FIG. 4). ) Is a production time when 0 is started (that is, substrate heating step S3). In addition, the vertical axis | shaft has shown the substrate temperature measured by the thermometer 25. As shown in FIG. In addition, a rapid temperature rise is observed immediately after the start of production, and the substrate temperature is constant until approximately 18 minutes have elapsed thereafter.

This shows that heating of the board | substrate S was performed by the board | substrate heating process S3 of FIG. 4, while 0 to 18 minutes of manufacture start pass. In addition, the temperature of the board | substrate S by the board | substrate heating process S3 was 110 degreeC, in order to make the packing density of each dielectric layer H, L high. In addition, before starting heating of the board | substrate S, the vacuum exhaust process S2 of FIG. 4 is performed.

Then, after about 18 minutes have elapsed since the start (line A in FIG. 6), it was confirmed that the pressure in the vacuum chamber 2 was about 1 × 10 ⁻³ Pa. It is determined that the pressure in the chamber 2 is 1 × 10 ⁻³ Pa or less, and thereafter, before the dielectric layer forming step S7 is performed, the substrate holding / holding means rotating step S5 and the substrate cleaning step of FIG. 4 ( S6) is performed.

In FIG. 6, the increase in the substrate temperature is observed when it is about 19 minutes. This is because the substrate cleaning step S6 is performed by ion cleaning. After the ion cleaning is completed, a decrease in the substrate temperature is observed.

Subsequently, the substrate temperature is increased and decreased until the line B in FIG. 6 is reached. However, this is performed by forming the dielectric layers H and L in order by the dielectric layer forming step S7 of FIG. Indicates that there is. In addition, between 20-27 minutes in FIG. 6, the 1st, 2nd layer of the high refractive index dielectric layer H, and the 1st, 2nd layer of the low refractive index dielectric layer L are alternately formed on the board | substrate S, respectively. Indicates that there is.

After all the dielectric layers are formed (that is, line B in FIG. 6), cooling is started by the cooling step S9 of FIG. 4. At this time, the substrate heating stop step (S8) is also performed at the same time. The gentle fall of the substrate temperature observed between the lines B and C in FIG. 6 indicates that cooling is being performed. In more detail, it shows cooling from 27 minutes after manufacture start to about 57 minutes (30 minutes, time shown by the arrow in FIG. 6).

Subsequently, a slight increase in substrate temperature was observed about 45 minutes from the start of manufacture (line C in FIG. 6), because the Al crucible for depositing the reflective layer R was preheated with an electron beam for 1 minute. to be. At this time, the pressure in the vacuum chamber 2 was 5.0 * 10 <^-4> Pa or less.

In addition, ion cleaning by ion beam was performed for 1 minute with respect to the film | membrane in which the reflective layer R is laminated | stacked after that. In addition, the pressure in the vacuum chamber 2 at the time of ion cleaning was about 2.1 * 10 <^-2> Pa.

Ion cleaning conditions by an ion beam were performed under the following conditions.

Ion cleaning conditions

Inlet gas: Oxygen 60 sccm

Ion Acceleration Voltage: 500 V

Ion Current: 500 mA

Neutralizer Conditions

Neutralizer Current: 1000 mA

Discharge gas: Argon 10 sccm

Subsequently (after line D in FIG. 6), the inside of the vacuum chamber 2 is depressurized while cooling the substrate S until the vacuum chamber 2 has an appropriate pressure range in order to form the reflective layer R. It was. When 55 minutes have elapsed since the start of manufacture (line E in FIG. 6), the pressure in the vacuum chamber 2 is 3 × 10 ⁻⁴ Pa or less in the second determination step S10 of FIG. 4, and the substrate temperature is increased. It was confirmed that it was 50 degrees C or less.

In addition, at this time, the inside of the vacuum chamber 2 showed 2.0 * 10 <^-4> Pa, and the radiation thermometer showed 30 degreeC.

55 minutes to 57 minutes (between line E and line F in FIG. 6) from the start of manufacture, so that the pressure in the vacuum chamber 2 may be 2.0-3.0 * 10 <^-4> Pa, and an Al film is deposited with respect to the board | substrate S. Thus, the reflective layer R was formed (reflective layer forming step (S11)).

In addition, since the board | substrate S was cooled at this time, the big temperature rise was not observed but was substantially constant.

Then, it cooled further until the temperature of the board | substrate S became near room temperature, and leaked the vacuum chamber 2 (leak process S12).

Therefore, in this embodiment, after the dielectric layer was formed (line B in FIG. 6), the substrate was cooled for 28 minutes until the formation of the reflective layer R (line E in FIG. 6). In the conventional method, in order to form the reflective layer R, the substrate temperature was cooled to 50 ° C or lower, and the cooling time required about 2 to 3 hours. On the other hand, in this embodiment, the substrate temperature can be cooled down to a lower room temperature vicinity, and the cooling time can be made very short (28 minutes).

In addition, the reflective layer R was formed into a film on condition of the following.

Reflective Material: Al

Deposition rate of Al: 2.5 nm / sec

The reflectance at 450-470 nm (light emission wavelength range of a blue LED) of the reflective layer R formed into a film in this Example was 98%. Therefore, according to the present invention, the reflective layer R of the semiconductor light emitting element substrate has a good reflectance and can effectively shorten the manufacturing time.

Claims (7)

On the substrate, a dielectric layer in which a layer made of any one of titanium oxide, zirconium oxide, tantalum oxide or niobium oxide is alternately combined with a layer made of any one of aluminum oxide, silicon oxide or magnesium fluoride, As a manufacturing method of a semiconductor light emitting element substrate provided with a reflective layer made of aluminum in order on one surface thereof,
A substrate holding and holding step of holding and holding the substrate in a substrate holding and holding means disposed in a vacuum chamber;
A vacuum exhaust process of exhausting the inside of the vacuum chamber,
A substrate heating step performed at the same time as the vacuum evacuation step and heating the substrate;
A substrate cleaning step of cleaning the substrate by irradiating the substrate with ions;
A dielectric layer forming step of depositing the dielectric layer on the substrate at a substrate temperature of 100 ° C. to 120 ° C .;
A substrate heating stop step of stopping heating of the substrate;
The cooling means disposed in a position in contact with the substrate as a vicinity of the substrate absorbs radiant heat from the substrate and the substrate holding and holding means to start cooling the substrate and the substrate holding and holding means. Cooling process,
And a reflecting layer forming step of depositing the reflecting layer on the dielectric layer at the substrate temperature of 25 ° C to 70 ° C in this order. On the substrate, a dielectric layer in which a layer made of any one of titanium oxide, zirconium oxide, tantalum oxide or niobium oxide is alternately combined with a layer made of any one of aluminum oxide, silicon oxide or magnesium fluoride, As a manufacturing method of a semiconductor light emitting element substrate provided with a reflective layer made of aluminum in order on one surface thereof,
A substrate holding and holding step of holding and holding the substrate in a substrate holding and holding means disposed in the vacuum chamber;
A vacuum exhaust process of exhausting the inside of the vacuum chamber,
A substrate heating step performed at the same time as the vacuum evacuation step and heating the substrate;
The cooling means disposed in a position in contact with the substrate as a vicinity of the substrate absorbs radiant heat from the substrate and the substrate holding and holding means to start cooling the substrate and the substrate holding and holding means. Cooling process,
A substrate cleaning step of cleaning the substrate by irradiating the substrate with ions;
A dielectric layer forming step of depositing the dielectric layer on the substrate at a substrate temperature of 100 ° C. to 120 ° C .;
A substrate heating stop step of stopping heating of the substrate;
And a reflecting layer forming step of depositing the reflecting layer on the dielectric layer at the substrate temperature of 25 ° C to 70 ° C in this order. The method according to claim 1 or 2,
Before the substrate cleaning step, further comprising a first determination step of determining whether the inside of the vacuum chamber is 1 × 10 ^-3 Pa or less,
A method for manufacturing a semiconductor light emitting device substrate, characterized in that the substrate cleaning step is performed when the inside of the vacuum chamber is 1 × 10 ⁻³ Pa or less. The method of claim 3,
And further including a second determination step of determining whether the temperature of the substrate is 50 ° C. or lower and whether the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less before the reflection layer forming step,
And the reflection layer forming step is performed when the temperature of the substrate is 50 ° C. or less and the inside of the vacuum chamber is 3 × 10 ⁻⁴ Pa or less. The method of claim 4, wherein
The second judgment step includes a vacuum pump connected to the vacuum chamber via a vacuum valve, a pressure control means connected to the vacuum valve, a thermometer provided near the substrate, and a temperature control means connected to the cooling means. Done by
And the reflective layer forming step is performed by controlling the shutter control means connected to the pressure control means and the temperature control means to open the shutter disposed on the evaporation source. delete delete

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