JP6040898B2 - III-nitride semiconductor light emitting device manufacturing method and manufacturing apparatus, and substrate cleaning method - Google Patents

Description

  The present invention relates to a method and apparatus for manufacturing a group III nitride semiconductor light-emitting device, in which cleaning is performed on a growth substrate before a semiconductor layer is grown, and a substrate cleaning method.

  A group III nitride semiconductor light-emitting device is generally manufactured by growing a semiconductor layer made of a group III nitride semiconductor on a growth substrate. As the growth method, there are growth methods such as metal organic chemical vapor deposition (MOCVD), hydride vapor deposition, molecular beam epitaxy, and liquid phase epitaxy.

  For example, in an MOCVD furnace used in the MOCVD method, a crystal film caused by a by-product is formed on the inner wall of the furnace by repeated use. The crystal film resulting from this by-product is peeled off from the inner wall of the furnace due to some trigger and becomes dust. Such dust may adhere to the growing wafer. Of the semiconductor light-emitting elements cut out from the wafer, the semiconductor light-emitting elements manufactured from the dust-attached portion often do not have sufficient performance. That is, the yield is poor.

  Therefore, techniques for removing dust have been developed. For example, Patent Document 1 discloses an apparatus for cleaning the surface of a substrate. Patent Document 1 discloses a technique for preventing reattachment of dust to a substrate by flowing a gas in the lateral direction (see paragraph [0015] and the like of Patent Document 1). However, Patent Document 1 discloses a cleaning device, not a device for growing a semiconductor layer. Patent Document 2 discloses a technique for ejecting an inert gas at a flow rate of 10 m / sec or more to remove particles in the reactor (see Paragraph [0035] of Patent Document 2 and FIG. 3). .

JP 2006-140492 A JP 2006-318959 A

  However, when a cleaned substrate is placed on an internal susceptor such as an MOCVD furnace, dust may be placed on the growth substrate within the period from the placement of the growth substrate to the growth of the semiconductor. The technique described in Patent Document 1 is a cleaning device that is implemented before being placed in a furnace. Therefore, with this technique, it is impossible to clean the substrate after placing the growth substrate in the MOCVD furnace. In the technique of Patent Document 2, after cleaning (S0 in FIG. 1 of Patent Document 2), a pressure reducing process (S1 in FIG. 1 of Patent Document 2) and a temperature raising process (S2 in FIG. 1 of Patent Document 2). In the period of), there is still a possibility that dust will be placed on the substrate.

  The present invention has been made to solve the above-described problems of the prior art. That is, the subject is providing the manufacturing method and manufacturing apparatus of a group III nitride semiconductor light-emitting device which perform cleaning to the growth substrate before growing a semiconductor layer, and the cleaning method of a board | substrate.

The method for producing a group III nitride semiconductor light-emitting device in the first aspect is a method for forming a group III nitride semiconductor layer on a substrate. This manufacturing method includes a dust removal step of removing dust on the substrate by blowing gas onto the substrate, and a semiconductor layer growth step of epitaxially growing a group III nitride semiconductor layer on the substrate. The dust removing step includes a first dust removing step of blowing gas onto the substrate at a first flow rate, and a gas flow rate at least including a second flow rate that is faster than the first flow rate after the first dust removing step. And a second dust removing step of spraying on the substrate. The second dust removal step includes a high-speed period in which gas is blown to the substrate at the second flow rate and a low-speed period in which gas is blown to the substrate at a third flow rate slower than the second flow rate. Further, in the second dust removal step, the high speed period and the low speed period are alternately repeated.

This method for manufacturing a group III nitride semiconductor light-emitting device is a method for performing a first dust removal step and a second dust removal step. In the second dust removal step, gas is blown toward the growth substrate at a flow rate different from that in the first dust removal step, so that dust can be suitably removed. Moreover, since the high-speed period and the low-speed period are alternately repeated, the gas flow pulsates. Therefore, dust can be removed suitably. As a result, a method for manufacturing a group III nitride semiconductor light-emitting device excellent in yield has been realized.

In the method for manufacturing a group III nitride semiconductor light-emitting device in the second aspect , the third flow rate is slower than the first flow rate. In this condition, the pulsation of the gas flow is large.

In the Group III nitride semiconductor light emitting device manufacturing method according to the third aspect, the third flow rate is equal to or higher than the first flow rate and slower than the second flow rate. Even under this condition, pulsation of the gas flow can be generated.

In the method for manufacturing a Group III nitride semiconductor light-emitting device according to the fourth aspect, in the first dust removal step, the first flow velocity is not less than 0.2 m / sec and not more than 0.7 m / sec. In the second dust removal step, the second flow velocity is a flow velocity that is 0.1 m / sec or more faster than the first flow velocity.

In the Group III nitride semiconductor light-emitting device manufacturing method according to the fifth aspect, in the first dust removing step, the first flow velocity is not less than 0.2 m / sec and not more than 0.7 m / sec. In the second dust removal step, the second flow velocity is a flow velocity that is 0.1 m / sec or more faster than the first flow velocity. Furthermore, the third flow velocity is 0.1 m / sec or more and 0.6 m / sec or less.

In the Group III nitride semiconductor light-emitting device manufacturing method according to the sixth aspect, in the first dust removal step, the first flow velocity is 0.2 m / sec or more and 0.7 m / sec or less. In the second dust removal step, the second flow velocity is a flow velocity that is 0.2 m / sec or more faster than the first flow velocity. Furthermore, the third flow velocity is 0.2 m / sec or more.

In the method for manufacturing a group III nitride semiconductor light emitting device according to the seventh aspect, a manufacturing apparatus for epitaxially growing a group III nitride semiconductor layer is used. Then, the dust removal process is performed in any period from the placement of the substrate in the manufacturing apparatus to the start of growth of the semiconductor layer on the substrate.

The manufacturing method of the group III nitride semiconductor light-emitting device in the eighth aspect includes a substrate heating step of heating the substrate. And after stopping the heating in a substrate heating process, a dust removal process is implemented.

According to a ninth aspect of the present invention , there is provided a group III nitride semiconductor light emitting device manufacturing method comprising: a substrate heating step for heating a substrate; and a period from when heating in the substrate heating step is stopped to when growth of a semiconductor layer is started on the substrate And a dust removing step of removing dust on the substrate by blowing gas onto the substrate, and a semiconductor layer growing step of epitaxially growing a group III nitride semiconductor layer on the substrate. The dust removing process includes a first dust removing process in which a gas is blown to the substrate at a first flow rate, and a gas at a flow rate that includes at least a second flow rate that is faster than the first flow rate after the first dust removing step. And a second dust removing step of spraying on.

The blowing can give gas, it is possible to cool the substrate.

The substrate cleaning method according to the tenth aspect is a method of removing dust on the substrate. This cleaning method includes a dust removal step of blowing gas onto the substrate. The dust removing step includes a first dust removing step of blowing gas onto the substrate at a first flow rate, and a gas flow rate at least including a second flow rate higher than the first flow rate after the first dust removing step. And a second dust removing step of spraying on the substrate. The second dust removal step includes a high-speed period in which gas is blown to the substrate at the second flow rate and a low-speed period in which gas is blown to the substrate at a third flow rate slower than the second flow rate. In the second dust removal step, the high speed period and the low speed period are alternately repeated.

A group III nitride semiconductor light emitting device manufacturing apparatus according to an eleventh aspect includes a susceptor for arranging a substrate, a chamber for housing the susceptor, a nozzle for blowing gas toward the substrate, and a flow rate of the gas flowing out from the nozzle. And a flow control unit for controlling. The flow rate controller controls the first flow rate for blowing the gas to the substrate at the first flow rate, and the second flow rate control for blowing the gas to the substrate at a flow rate at least including a second flow rate faster than the first flow rate. ,I do. The second flow rate control includes a high-speed period in which gas is blown to the substrate at a second flow rate and a low-speed period in which gas is blown to the substrate at a third flow rate that is slower than the second flow rate. In the second flow rate control, the high speed period and the low speed period are alternately repeated.

  The present invention provides a method and apparatus for manufacturing a group III nitride semiconductor light emitting device and a method for cleaning a substrate, in which the growth substrate before the growth of the semiconductor layer is cleaned.

It is a schematic block diagram which shows the structure of the semiconductor light-emitting device which concerns on embodiment. It is a figure which shows the manufacturing apparatus of the semiconductor light-emitting device which concerns on embodiment. It is a graph (the 1) explaining the cleaning method of the 1st board | substrate which concerns on an Example. It is a graph (the 2) explaining the cleaning method of the 2nd board | substrate which concerns on an Example. It is a graph explaining the cleaning method of the 3rd board concerning a comparative example.

  Hereinafter, specific embodiments will be described with reference to the drawings, taking a method for manufacturing a semiconductor light emitting device as an example. However, it is not limited to these embodiments.

1. Semiconductor Light Emitting Element FIG. 1 shows a schematic configuration of a light emitting element 100 according to this embodiment. The light emitting element 100 is a face-up type semiconductor light emitting element. The light emitting element 100 has a plurality of semiconductor layers made of a group III nitride semiconductor.

  As shown in FIG. 1, the light emitting device 100 includes a substrate 110, a low-temperature buffer layer 120, an n-type contact layer 130, an n-type ESD layer 140, an n-type SL layer 150, a light-emitting layer 160, a p-type. The clad layer 170, the p-type contact layer 180, the n-electrode N1, the p-electrode P1, and the passivation film F1 are included. The n-type contact layer 130, the n-type ESD layer 140, and the n-type SL layer 150 are n-type semiconductor layers. The p-type cladding layer 170 and the p-type contact layer 180 are p-type semiconductor layers.

  The substrate 110 is a growth substrate for forming each of the semiconductor layers on the main surface by MOCVD. The surface of the substrate 110 may or may not be uneven. The material of the substrate 110 is sapphire. In addition to sapphire, materials such as SiC, ZnO, Si, and GaN may be used.

2. Manufacturing Apparatus FIG. 2 shows a Group III nitride semiconductor light emitting device manufacturing apparatus 1000 according to this embodiment. The manufacturing apparatus 1000 is a MOCVD furnace for epitaxially growing a semiconductor layer on a growth substrate. The manufacturing apparatus 1000 is used to perform a substrate cleaning method described later. The manufacturing apparatus 1000 includes a susceptor 1110, a heater 1120, a rotating shaft 1130, a chamber 1200, a nozzle 1410, a suction unit 1420, and a control unit 1500.

  The susceptor 1110 is a support member for supporting the substrate 110. Therefore, the susceptor 1110 can arrange | position the board | substrate 110. FIG. The heater 1120 is for heating the substrate 110. The rotation shaft 1130 is for rotating the susceptor 1110. Thereby, the semiconductor layer can be grown on the substrate 110 while rotating the substrate 110.

  The chamber 1200 is a furnace main body for accommodating each part. The nozzle 1410 is for supplying a carrier gas and a source gas into the chamber 1200. When the manufacturing apparatus 1000 is used, the nozzle 1410 supplies gas toward the substrate 110 disposed on the susceptor 1110. The suction part 1420 is for sucking the gas inside the chamber 1200.

  The chamber 1200 has a channel upper surface 1310, a channel lower surface 1320, and a channel side surface 1330. The channel upper surface 1310, the channel lower surface 1320, and the channel side surface 1330 are for allowing the gas supplied from the nozzle 1410 to pass above the substrate 110 disposed on the susceptor 1110. As shown in FIG. 2, the manufacturing apparatus 1000 of the present embodiment blows gas onto the substrate 110 from the lateral direction.

  The control unit 1500 is for controlling each unit of the manufacturing apparatus 1000. The control unit 1500 also serves as a flow rate control unit that controls the flow rate of carrier gas, source gas, and the like supplied from the nozzle 1410. The control unit 1500 controls the temperature of the heater 1120, the rotation of the rotating shaft 1130, and the like.

3. Substrate Cleaning Method Here, a substrate cleaning method according to this embodiment will be described. In the substrate cleaning method of this embodiment, dust on the substrate 110 is removed by blowing gas onto the substrate 110. As this gas, any one of H ₂ , N ₂ , NH _3, and a mixed gas thereof may be used. These gases may contain silane (SiH ₄ ) and organometallic materials such as trimethyl gallium and trimethyl aluminum described later. The temperature of the gas ejected from the nozzle 1410 is about 20 ° C. Of course, other temperatures may be used. The pressure inside the chamber 1200 is almost atmospheric pressure. Of course, cleaning may be performed under a pressurized condition or a reduced pressure condition. When performing the cleaning method of this embodiment, the cleaning is performed while rotating the substrate 110. However, the rotational speed is sufficiently slower than the flow rate of the flowing gas. Of course, the cleaning may be performed in a state where the rotation of the rotation shaft 1130 is stopped.

  In the substrate cleaning method of the present embodiment, the control unit 1500 of the manufacturing apparatus 1000 performs the first flow rate control and the second flow rate control. The first flow rate control is for controlling the flow rate of the gas in the first dust removal step described later. The second flow rate control is for controlling the flow rate of the gas in the second dust removal step described later. Here, the flow velocity is a gas flow velocity on the surface of the substrate 110. The flow rate is determined by the flow rate of the gas supplied from the nozzle 1410 and the cross-sectional area through which the gas flows on the surface of the substrate 110. Therefore, the control unit 1500 can also control the gas flow rate by controlling the gas flow rate.

3-1. First cleaning method (Example)
FIG. 3 is a graph for explaining the first cleaning method. The horizontal axis of FIG. 3 is time (sec). The vertical axis | shaft of FIG. 3 is a flow velocity (m / sec). The reference time “0” is the time when heating of the substrate 110 is stopped in the substrate heating process described later. The substrate cleaning process in the first cleaning method, that is, the dust removing process, includes a first dust removing process and a second dust removing process. The first dust removal step is performed in the first period T1 shown in FIG. The second dust removal step is performed in the second period T2 shown in FIG.

  In the first dust removal step, the gas is blown toward the substrate 110 while being kept constant at the first flow rate. The first flow velocity is, for example, 0.6 m / sec. In the second dust removal step, gas is blown toward the substrate 110 while keeping the second flow rate constant. The second flow velocity is, for example, 0.9 m / sec. The first period T1 is, for example, not less than 3 minutes and not more than 10 minutes. The second period T2 is, for example, not less than 1 minute and not more than 5 minutes. The first period T1 and the second period T2 need not be in these ranges. Note that the temperature of the substrate 110 at time 0 is approximately 1250 ° C. The temperature of the substrate 110 immediately after the elapse of the second period T2 is 350 ° C. That is, in this cleaning method, the temperature of the substrate 110 is set within a range of 350 ° C. or higher and 1250 ° C. or lower.

3-2. Second cleaning method (Example)
FIG. 4 is a graph for explaining the second cleaning method. The horizontal axis of FIG. 4 is time (sec). The vertical axis | shaft of FIG. 4 is a flow velocity (m / sec). The substrate cleaning process in the second cleaning method includes a first dust removing process and a second dust removing process. The first dust removal step is performed in the first period T3 shown in FIG. The second dust removal step is performed in the second period T4 shown in FIG.

  In the first dust removal step, the gas is blown toward the substrate 110 while being kept constant at the first flow rate. The first flow velocity is, for example, 0.6 m / sec. In the second dust removal step, the gas is blown toward the substrate 110 by alternately repeating a high flow rate and a low flow rate. At this time, the fast flow rate is set as the second flow rate. The second flow velocity is, for example, 0.9 m / sec. The slow flow rate is the third flow rate. The third flow velocity is, for example, 0.3 m / sec. The second flow rate is faster than the first flow rate. The third flow rate is slower than both the first flow rate and the second flow rate. Here, a period in which gas is blown onto the substrate 110 at the second flow rate is referred to as a high-speed period, and a period in which gas is blown onto the substrate 110 at the third flow rate is referred to as a low-speed period. Here, the second dust removal step includes a high speed period and a low speed period. And in a 2nd dust removal process, a high speed period and a low speed period are repeated alternately.

  The first period T3 is, for example, not less than 3 minutes and not more than 10 minutes. The second period T4 is, for example, not less than 1 minute and not more than 5 minutes. The first period T3 and the second period T4 need not be in these ranges. Note that the temperature of the substrate 110 at time 0 is approximately 1250 ° C. The temperature of the substrate 110 immediately after the elapse of the second period T4 is 350 ° C. That is, in this cleaning method, the temperature of the substrate 110 is set within a range of 350 ° C. or higher and 1250 ° C. or lower. In addition, the number of repetitions of the high speed period and the low speed period is preferably 5 to 10 times. Of course, the number is not limited to this.

  As described above, in the first dust removing step, a flow velocity within the range of 0.2 m / sec to 0.7 m / sec is set as the first flow velocity. Desirably, it is in the range of 0.3 m / sec to 0.6 m / sec. The second dust removal step includes a period in which gas is blown onto the substrate 110 at least at the second flow rate. In the second dust removal step, a flow rate that is 0.1 m / sec or more faster than the first flow rate is set as the second flow rate. If the second flow rate is too high, the exhaust capacity of the manufacturing apparatus 1000 may be exceeded. Moreover, there is a possibility that the by-product adhering to the inner wall of the manufacturing apparatus 1000 may be peeled off from the inner wall. That is, there is a possibility that new dust floating inside the chamber 1200 may be generated. Therefore, the second flow rate is preferably 10 m / sec or less. Desirably, it is in the range of 0.9 m / sec or more and 5 m / sec or less. More desirably, it is in the range of 0.9 m / sec or more and 1.3 m / sec or less. When setting the third flow velocity, a flow velocity that is slower than the second flow velocity and within a range of 0.1 m / sec or more is set as the third flow velocity. Desirably, it is in the range of 0.1 m / sec to 0.6 m / sec. The difference between the second flow rate and the third flow rate is preferably 0.1 m / sec or more. Further, the difference between the second flow rate and the third flow rate is more preferably 0.2 m / sec or more. This is because more preferable gas pulsation can be generated.

3-3. Third cleaning method (comparative example)
FIG. 5 is a graph for explaining the third cleaning method. The horizontal axis of FIG. 5 is time (sec). The vertical axis in FIG. 5 is the flow velocity (m / sec). The third cleaning method is not the cleaning method of the present embodiment, but is a cleaning method corresponding to the comparative example to the last. In the third cleaning method, gas is blown toward the substrate 110 at a constant flow rate of 0.6 m / sec. Simply blowing gas toward the substrate 110 at a constant flow rate has a small effect of removing dust from the upper surface of the substrate 110, as shown in an experiment described later.

4). Manufacturing Method of Semiconductor Light-Emitting Element Here, a manufacturing method of the light-emitting element 100 according to this embodiment will be described. Crystals of each semiconductor layer are epitaxially grown by metal organic chemical vapor deposition (MOCVD). The carrier gas used here is hydrogen (H ₂ ) or nitrogen (N ₂ ) or a mixed gas of hydrogen and nitrogen (H ₂ + N ₂ ). Ammonia gas (NH ₃ ) is used as a nitrogen source. As a Ga source, trimethylgallium (Ga (CH ₃ ) ₃ ) or triethylgallium (Ga (C ₂ H ₅ ) ₃ ) is used. Trimethylindium (In (CH ₃ ) ₃ ) is used as the In source. Trimethylaluminum (Al (CH ₃ ) ₃ ) is used as the Al source. Silane (SiH ₄ ) is used as the n-type dopant gas. Cyclopentadienyl magnesium (Mg (C ₅ H ₅ ) ₂ ) is used as the p-type dopant gas.

4-1. Substrate Arrangement Step The substrate 110 is arranged on the susceptor 1110 of the manufacturing apparatus 1000. At this time, the manufacturing apparatus 1000 is inside a glove box (not shown). When the substrate 110 is placed on the susceptor 1110, dust may enter the manufacturing apparatus 1000. Alternatively, the by-product on the inner wall of the manufacturing apparatus 1000 may float and become dust.

4-2. Substrate heating process (substrate baking process)
Next, the heater 1120 is heated while rotating the rotating shaft 1130. Thereby, the substrate 110 is heated while rotating. Then, hydrogen gas is supplied from the nozzle 1410. Thereby, the surface of the substrate 110 is reduced. That is, a surface suitable for forming a semiconductor layer can be obtained. The temperature of the substrate 110 at this time is about 1250 ° C. During this heating process, dust may adhere to the surface of the substrate 110.

4-3. Dust removal process (substrate cleaning process)
After the heating in the substrate heating process is stopped, the substrate 110 is cleaned. Here, gas is blown onto the substrate 110 in order to remove dust adhering to the surface of the substrate 110. Thereby, dust is removed from the substrate 110. More dust can be removed from the substrate 110 by performing the first dust removing step and the second dust removing step. Note that the gas after sprayed onto the substrate 110 is sucked into the suction unit 1420. Therefore, there is almost no possibility that the dust removed from the substrate 110 will adhere to the surface of the substrate 110 again.

4-4. Semiconductor Layer Growth Step On the main surface of the substrate 110, the low-temperature buffer layer 120, the n-type contact layer 130, the n-type ESD layer 140, the n-type SL layer 150, the light emitting layer 160, and the p-type cladding layer 170. And the p-type contact layer 180 are epitaxially grown in this order.

4-5. Electrode Formation Step Next, a non-through hole reaching from the p-type contact layer 180 side to the n-type contact layer 130 is dug. Then, an n-electrode N1 is formed on the exposed n-type contact layer 130. On the other hand, a p-electrode P1 made of ITO or the like is formed on the p-type contact layer 180.

4-6. Other Steps Then, a passivation film F1 is formed on the element. Moreover, you may implement another heat processing process. Also, the elements are separated. Thus, the light emitting device 100 is manufactured.

5. Experiment 5-1. Experimental Conditions Here, an experiment of a group III nitride semiconductor light emitting device manufactured using the substrate cleaning method of the present embodiment will be described. In this experiment, dust on the substrate 110 was removed by the second cleaning method (Example) and the third cleaning method (Comparative Example).

  As shown in Tables 1 and 2, the period for performing the cleaning method and the temperature of the substrate 110 are common to the second cleaning method and the third cleaning method. Table 1 shows the conditions of the second cleaning method. The cleaning period was 6.3 minutes, including 4.3 minutes in the first period and 2 minutes in the second period. The time for continuing the second flow rate in the second period was 15 seconds, and the time for continuing the third flow rate in the second period was 5 seconds. These repetitions were 6 times. Therefore, the total time of the second period was 2 minutes. The first flow rate of gas in the first period was 0.6 m / sec. The second flow rate of the gas in the second period was 0.9 m / sec. The third gas flow rate in the second period was 0.3 m / sec. Hydrogen gas was used as the gas type.

[Table 1]
Second cleaning method (Example)
Period 6.3 minutes First period 4.3 minutes Second period 2 minutes Second flow rate duration 15 seconds Third flow rate duration 5 seconds Number of repetitions 6 times Flow rate First flow rate 0.6 m / sec
Second flow velocity 0.9m / sec
Third flow velocity 0.3m / sec
Substrate temperature The temperature of the substrate before the first period 1250 ° C
The temperature of the substrate after the second period 350 ° C.

  Table 2 shows conditions for the third cleaning method. In the third cleaning method, the cleaning period is set to 6.3 minutes. The flow rate was set to a constant 0.6 m / sec.

[Table 2]
Third cleaning method (comparative example)
Period Period 6.3 minutes Flow velocity Flow velocity 0.6m / sec
Substrate temperature The temperature of the substrate before the first period 1250 ° C
The temperature of the substrate after the second period 350 ° C.

5-2. Experimental results Table 3 shows the experimental results. As shown in Table 3, when the second cleaning method was performed, an average of 10 dusts were present on one wafer. When the third cleaning method was performed, 19 dusts were present on average on one wafer. Thus, in the second cleaning method corresponding to the example, dust could be sufficiently removed as compared with the third cleaning method corresponding to the comparative example.

[Table 3]
Cleaning method Number of dust per wafer (average value)
10 second cleaning methods 19 third cleaning methods

  Further, the yield of the semiconductor light emitting device manufactured separately from the wafer was as follows. That is, the ratio of defective products when the second cleaning method was used was 0.21%. The ratio of defective products when the third cleaning method was used was 0.77%. That is, the yield was improved by 0.56%. However, this evaluation is limited to those caused by dust, and other causes other than dust are not included.

6). Modification 6-1. Modification Example of Manufacturing Apparatus A manufacturing apparatus having a configuration different from that of the manufacturing apparatus 1000 illustrated in FIG. 2 may be used. In FIG. 2, the substrate 110 and the channel upper surface 1310 are schematically drawn in parallel. However, for example, a configuration in which the distance between the substrate 110 and the flow path upper surface 1310 becomes narrower toward the suction unit 1420 from the nozzle 1410 may be adopted. As described above, the distance between the substrate 110 and the flow path upper surface 1310 may be not uniform. In that case, the gas flow rates are not equal across the entire wafer surface. In that case, the position where the gas flow velocity becomes fastest in the wafer may be used as a reference. When the distance between the substrate 110 and the flow path upper surface 1310 is not uniform, the gas flow velocity at the position where the distance is the narrowest may be defined as the second flow velocity or the like.

  Moreover, in this embodiment, the manufacturing apparatus 1000 which flows carrier gas and source gas to a horizontal direction was used. However, the nozzle direction is not limited to the horizontal direction. The present invention can also be applied to a case where a carrier gas or the like is supplied from a nozzle disposed in the center of the chamber to clean the substrate 110 disposed around the nozzle. In that case, the position on the wafer where the gas flow velocity is the fastest may be used as a reference. In other words, the gas flow velocity at the closest location on the substrate 110 as viewed from the nozzle may be defined as the second flow velocity or the like.

  Moreover, it is not restricted to the manufacturing apparatus which flows carrier gas from a horizontal direction. The carrier gas may flow from above. Moreover, it may be ejected from the center of the manufacturing apparatus and spread outside. Even in such a case, the second flow rate or the like may be defined at the position where the gas flow rate is fastest in the plane of the wafer.

6-2. Type of Manufacturing Apparatus In the present embodiment, the MOCVD furnace has been described. However, any other manufacturing apparatus used for the vapor phase epitaxy method can be similarly applied.

6-3. Timing of performing cleaning In the present embodiment, the substrate is cleaned after the substrate heating step (substrate baking step). However, the substrate may be cleaned after the growth substrate is placed on the susceptor 1110 and before the formation of the semiconductor layer on the growth substrate is started. However, the cleaning of the substrate is preferably performed when the growth substrate is cooled in order to blow gas onto the growth substrate. This is because cleaning and substrate cooling can be performed simultaneously.

6-4. Types of Light-Emitting Elements In this embodiment, the face-up type light-emitting element 100 has been described as an example. However, in addition to the present embodiment, the present invention can be applied to a flip-chip light-emitting element and a substrate lift-off light-emitting element. Needless to say, the stacked structure of the semiconductor layers of the present embodiment is an exemplification, and may be a structure other than those shown.

6-5. In this embodiment, the dust removed from the substrate 110 is a by-product. This by-product contains elements such as Ga, In, Al, and C. However, if other particles enter the manufacturing apparatus 1000 when the chamber is opened and closed, the particles may fall on the substrate 110. The cleaning method of this embodiment can also remove such particles.

6-6. Third Flow Rate In the second cleaning method of this embodiment, the third flow rate is slower than both the first flow rate and the second flow rate. However, the third flow rate may be higher than the first flow rate and slower than the second flow rate. This is because even in this case, the gas is supplied to the substrate while pulsating. In this case, it is preferable to set the second flow rate to a faster flow rate. For example, the second flow rate is set to a flow rate that is faster than the first flow rate by 0.2 m / sec or more. Even in this case, the second flow velocity is preferably 10 m / sec or less. The third flow rate may be set to 0.2 m / sec or more. Of course, the third flow rate is slower than the second flow rate.

6-7. Combination The above modification examples may be freely combined.

7). Summary of the present embodiment As described in detail above, in the method for manufacturing the light emitting device 100 of the present embodiment, the first dust removing step and the second dust removing step are performed. In the second dust removing step, the gas is blown toward the substrate 110 at a flow rate different from that in the first dust removing step, so that dust can be suitably removed. As a result, a method for manufacturing a group III nitride semiconductor light-emitting device excellent in yield has been realized.

  The embodiment described above is merely an example. Therefore, naturally, various improvements and modifications can be made without departing from the scope of the invention. The laminated structure of the laminated body is not necessarily limited to that shown in the drawing. You may select arbitrarily, such as a laminated structure and the repetition frequency of each layer. Moreover, it is not restricted to a metal organic chemical vapor deposition method (MOCVD method). Any other method may be used as long as the crystal is grown using a carrier gas.

8). Appendix (1) In the dust removal step, the temperature of the substrate is 350 ° C. or higher and 1250 ° C. or lower.
(2) Type of gas blown onto the substrate, and H _2, and N _2, and NH _3, that a mixture of these gases, is any of the.
(3) The first period is not less than 3 minutes and not more than 10 minutes, and the second period is not less than 1 minute and not more than 5 minutes.
(4) The number of repetitions of the high speed period and the low speed period should be 5 times or more and 10 times or less.

DESCRIPTION OF SYMBOLS 100 ... Light emitting element 110 ... Board | substrate N1 ... N electrode P1 ... P electrode 1000 ... Manufacturing apparatus 1110 ... Susceptor 1120 ... Heater 1130 ... Rotating shaft 1200 ... Chamber 1310 ... Channel upper surface 1320 ... Channel lower surface 1330 ... Channel side surface 1410 ... Nozzle 1420 ... Suction unit 1500 ... Control unit

Claims (11)

In a method for manufacturing a group III nitride semiconductor light-emitting device in which a group III nitride semiconductor layer is formed on a substrate,
A dust removing step of removing dust on the substrate by blowing gas on the substrate;
A semiconductor layer growth step of epitaxially growing the group III nitride semiconductor layer on the substrate;
Have
The dust removing step
A first dust removing step of blowing gas onto the substrate at a first flow rate;
After the first dust removal step, a second dust removal step of blowing gas onto the substrate at a flow rate at least including a second flow rate faster than the first flow rate;
I have a,
The second dust removing step
A high-speed period of blowing gas to the substrate at the second flow rate;
A low speed period in which gas is blown onto the substrate at a third flow rate that is slower than the second flow rate;
Including
A method of manufacturing a group III nitride semiconductor light emitting device, wherein the high-speed period and the low-speed period are alternately repeated. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 1 ,
The third flow rate is
A method for producing a group III nitride semiconductor light-emitting device, wherein the method is slower than the first flow rate. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 1 ,
The third flow rate is
A method for manufacturing a group III nitride semiconductor light-emitting device, wherein the method is higher than the first flow rate and slower than the second flow rate. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 1 ,
In the first dust removing step,
The first flow velocity is 0.2 m / sec or more and 0.7 m / sec or less,
In the second dust removal step,
The method of manufacturing a group III nitride semiconductor light emitting device, wherein the second flow rate is a flow rate that is 0.1 m / sec or more faster than the first flow rate. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 2 ,
In the first dust removing step,
The first flow velocity is 0.2 m / sec or more and 0.7 m / sec or less,
In the second dust removal step,
The second flow rate is a flow rate that is 0.1 m / sec or more faster than the first flow rate,
The method of manufacturing a group III nitride semiconductor light-emitting device, wherein the third flow velocity is 0.1 m / sec or more and 0.6 m / sec or less. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 3 ,
In the first dust removing step,
The first flow velocity is 0.2 m / sec or more and 0.7 m / sec or less,
In the second dust removal step,
The second flow rate is a flow rate that is faster than the first flow rate by 0.2 m / sec or more,
The method of manufacturing a group III nitride semiconductor light emitting device, wherein the third flow velocity is 0.2 m / sec or more. In the manufacturing method of the group III nitride semiconductor light-emitting device according to any one of claims 1 to 6 ,
Using a manufacturing apparatus for epitaxially growing the group III nitride semiconductor layer,
A Group III nitride semiconductor light-emitting device, wherein the dust removing step is performed in any period from the placement of the substrate in the manufacturing apparatus to the start of growth of a semiconductor layer on the substrate Manufacturing method. In the manufacturing method of the group III nitride semiconductor light-emitting device according to claim 7 ,
A substrate heating step of heating the substrate;
A method of manufacturing a group III nitride semiconductor light-emitting device, wherein the dust removal step is performed after heating in the substrate heating step is stopped. In a method for manufacturing a group III nitride semiconductor light-emitting device in which a group III nitride semiconductor layer is formed on a substrate,
A substrate heating step for heating the substrate;
A dust removing step of removing dust on the substrate by blowing a gas to the substrate during a period from when heating in the substrate heating step is stopped to when growth of a semiconductor layer is started on the substrate;
A semiconductor layer growth step of epitaxially growing the group III nitride semiconductor layer on the substrate;
Have
The dust removing step
A first dust removing step of blowing gas onto the substrate at a first flow rate;
After the first dust removal step, a second dust removal step of blowing gas onto the substrate at a flow rate at least including a second flow rate faster than the first flow rate;
A method for producing a Group III nitride semiconductor light-emitting device, comprising: In the substrate cleaning method of removing dust on the substrate,
Having a dust removal step of blowing gas onto the substrate;
The dust removing step
A first dust removing step of blowing gas onto the substrate at a first flow rate;
After the first dust removal step, a second dust removal step of blowing gas onto the substrate at a flow rate at least including a second flow rate faster than the first flow rate;
I have a,
The second dust removing step
A high-speed period of blowing gas to the substrate at the second flow rate;
A low speed period in which gas is blown onto the substrate at a third flow rate that is slower than the second flow rate;
Including
The substrate cleaning method , wherein the high-speed period and the low-speed period are alternately repeated . A susceptor for placing the substrate;
A chamber containing the susceptor;
A nozzle that blows gas toward the substrate;
A flow rate controller for controlling the flow rate of gas flowing out of the nozzle;
Have
The flow rate controller
First flow control for blowing gas onto the substrate at a first flow rate;
A second flow rate control for blowing gas onto the substrate at a flow rate that includes at least a second flow rate that is faster than the first flow rate;
The stomach line,
In the second flow rate control,
A high-speed period of blowing gas to the substrate at the second flow rate;
A low speed period in which gas is blown onto the substrate at a third flow rate that is slower than the second flow rate;
Including
An apparatus for manufacturing a group III nitride semiconductor light emitting device, wherein the high-speed period and the low-speed period are alternately repeated .

Images