TW201421574A - Substrate treatment device, substrate treatment method, and production method for semiconductor device - Google Patents

Abstract

To make full use of the area of an insulator substrate and improve the number of chips that can be produced per substrate while not requiring a separate attachment member and efficiently carrying out production in order to improve production cost performance. A substrate treatment method that comprises a substrate treatment step in which a wafer substrate (5) is arranged within a treatment chamber (2) that serves as a treatment chamber, power is supplied independently to an upper electrode (3) and a lower electrode (4), and treatment gas within the treatment chamber (2) is plasmified in order to treat the substrate. A treatment gas pressure adjustment step (stability step) in which the pressure of a treatment gas that is supplied into the treatment chamber (2) is adjusted to a predetermined pressure is carried out prior to a substrate treatment step for plasma etching treatment, and said treatment gas pressure adjustment step includes a substrate attachment step in which power is supplied only to the upper electrode (3), the treatment gas supplied into the treatment chamber (2) is plasmified, the wafer substrate (5) is charged with an electrical load, and the wafer substrate (5) is electrostatically attached to the lower electrode (4) side.

Description

Substrate processing apparatus, substrate processing method, and manufacturing method of semiconductor device

The present invention relates to a substrate processing apparatus used for electrostatically adsorbing and fixing a substrate to be processed, and performing specific processing such as plasma dry etching on a substrate to be processed, and a substrate processing method using the same, and a semiconductor device using the same Manufacturing method.

Previously, in the etching of the substrate to be processed, dry etching was performed under high vacuum. In the dry etching, the substrate to be processed is placed in a chamber, and a plasma is formed in the chamber, and etching is performed by the plasma. In such a dry etching process, the plasma dry etching characteristics largely depend on the substrate temperature. Therefore, the refrigerant is allowed to flow through the substrate supporting member supporting the substrate to be processed to control the substrate temperature. In this case, in order to improve the heat transfer efficiency of the refrigerant, a heat transfer gas such as He gas flows between the substrate to be processed and the substrate supporting member.

The substrate to be processed must be supported on the substrate supporting member in a fixed state in order to perform dry etching. Therefore, for example, in the case of a substrate-based semiconductor wafer to be processed, an electrostatic force acting on the semiconductor wafer in Coulomb force is used. The electrostatic adsorption device is adsorbed and supported on the substrate supporting member.

Fig. 11 is a schematic view for explaining the principle of electrostatic adsorption of the prior electrostatic adsorption device disclosed in Patent Document 1.

As shown in FIG. 11, the conventional electrostatic adsorption device 100 is disposed in a space in which plasma is formed, and the insulating substrate 101 is adsorbed on the side of the insulator 102. The adsorption member 104 includes an insulator 102 and an electrode 103 provided inside thereof. The adsorption member 104 is mounted and supported on the substrate supporting member 105.

A specific DC (Direct Current) voltage is applied to the electrode 103 in a state where plasma is formed in the space, whereby an electrostatic force is generated between the charge accumulated on the insulating substrate 101 and charged by the plasma and the electrode 103. This causes the insulating substrate 101 to be adsorbed to the insulator 102 side of the adsorption member 104.

FIG. 12 is a view schematically showing the configuration of a main part of a substrate processing apparatus disclosed in Patent Document 2.

As shown in FIG. 12, in the conventional plasma processing apparatus 200, a DC voltage is applied to the electrodes 202, 203 of the electrostatic chuck 201 on which the insulating substrate K is placed on the upper surface, and is supplied from the inert gas supply portion 205 to the processing chamber 204. An inert gas is supplied to plasma the inert gas. The insulating substrate K is charged from the plasma-inert inert gas to adsorb and hold the insulating substrate K on the electrostatic chuck 201. Thereafter, the supply of the cooling gas between the back surface of the insulating substrate K adsorbed and held on the electrostatic chuck 201 and the upper surface of the electrostatic chuck 201 is started.

Next, in the conventional plasma processing apparatus 200, the processing gas for plasma processing is supplied from the processing gas supply unit 206 to the processing chamber 204 instead of the inert gas, and the inside thereof is replaced with the processing gas, and the processing is performed. The gas is plasmad, and then the insulating substrate K is adsorbed and held on the electrostatic chuck 201. Thereafter, the cooling gas is supplied from the cooling gas supply unit 207, and the insulating substrate K is cooled by the cooling gas, and the insulating substrate K is subjected to plasma etching treatment by the plasma processing gas.

The exhaust device 208 includes: an exhaust pump 209; and an exhaust pipe 211 that connects the exhaust pump 209 and the lower container 210; and exhausts the gas in the lower container 210 via the exhaust pipe 211 to make the inside of the processing chamber 204 The inert gas or process gas becomes a specific pressure.

Thereby, the insulating substrate K can be cooled from the start of the plasma etching treatment, and the plasma etching treatment can be performed uniformly and efficiently on the entire surface of the insulating substrate K.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. Hei 11-111830

Patent Document 2: Japanese Patent Laid-Open Publication No. 2009-194194

When the mechanical chuck is used for the substrate holding, the number of wafers that can be obtained is reduced due to the mechanical chuck covering at least a portion of the peripheral edge portion of the wafer substrate. In the prior electrostatic adsorption device 100 disclosed in Patent Document 1, This ensures that the process achieves the pressure of the backside He for the desired cooling without the need for a mechanical chuck to maximize the efficient use of the surface area on the wafer substrate by substrate adsorption to increase the number of wafers available.

Specifically, the electrostatic adsorption principle of the electrostatic adsorption device 100 described above is described. The electrostatic adsorption device 100 is a RIE (Reactive Ion Etching) device, and only the upper electrode for plasma generation is present. The specific voltage is applied to the electrode 103 provided in the insulator 102 of the adsorption member 104 to electrostatically adsorb the insulating substrate 101. Thus, the adsorption member 104 for electrostatically adsorbing the insulating substrate 101 is not additionally required. Further, Patent Document 2 also has the following description. If the substrate adsorption holding step is not performed separately, the substrate is adsorbed and held in the plasma etching process for the substrate adsorption holding, and the substrate adsorption holding step is performed even if It is expected that plasma etching will also be promoted and correct etching processing will not be possible. Moreover, if the substrate adsorption holding step is additionally performed, the number of steps will increase, resulting in loss of efficiency in the manufacture of the semiconductor device.

In the substrate processing apparatus 200 of the prior art disclosed in Patent Document 2, the back surface He for cooling which achieves the required pressure for the process can be secured, and can be independently controlled by the ICP (Inductively Coupled Plasma) device. The upper electrode and the lower electrode, first, before the process gas is introduced into the processing chamber 204 from the processing gas supply unit 206 to adjust the pressure of the processing gas to a desired pressure, and before the plasma etching step, In addition, the substrate adsorption holding step is performed to drive only the upper electrode, and the inert gas introduced into the processing chamber 204 is plasmaized to electrostatically adsorb and hold the wafer substrate on the electrostatic chuck 201. The reason is If the substrate adsorption holding step is not performed separately but is performed during the plasma etching process, even if it is not expected, the plasma etching is advanced and the correct plasma etching process cannot be performed. As described above, if the substrate adsorption holding step is additionally performed, the number of steps becomes large, resulting in loss of efficiency in the manufacture of the semiconductor device.

The present invention has been made in view of the above problems, and an object thereof is to provide an apparatus for maximally utilizing an area on an insulator substrate to increase the number of wafers that can be taken per one substrate, and which can effectively be used without additionally requiring an adsorption member. A substrate processing apparatus which is manufactured to improve the manufacturing cost, and a substrate processing method using the same, and a method of manufacturing the semiconductor device using the same.

The substrate processing method of the present invention includes a substrate processing step of disposing a substrate in a processing chamber, supplying electric power independently to the upper electrode and the lower electrode, and plasma-treating the processing gas in the processing chamber to perform the substrate. Processing, the substrate processing method includes a substrate adsorption step in the process gas pressure adjustment step of adjusting the pressure of the processing gas supplied to the processing chamber to a specific pressure before the substrate processing step, the substrate adsorption step is only for the upper portion The electrode supplies electric power to plasma the processing gas supplied into the processing chamber, and the substrate is charged and the substrate is electrostatically adsorbed to the lower electrode side, thereby achieving the above object.

Further, it is preferable to select a gas type having a higher electron emission rate which is easier to be plasma-pulverized than the inert gas as the processing gas in the substrate processing method of the present invention.

Further, in the substrate processing method of the present invention, it is preferable that the gas species having a high electron emission rate which is easy to be pulverized is a treatment in which the ionization potential is lower than a specific value and the ionization voltage Vi of the gas is lower than another specific value. gas.

Furthermore, it is preferable that the processing gas of the substrate processing method of the present invention contains a gas having an ionization potential of 320 kcal/mol or less as an adsorption gas.

Further, it is preferable that the processing gas in the substrate processing method of the present invention contains O (oxygen) And a gas of at least one of Cl (chlorine).

Furthermore, in the substrate adsorption step in the substrate processing method of the present invention, the substrate-based insulating substrate is preferably electrostatically adsorbed by an electrostatic chuck (ESC).

Furthermore, it is preferable to cool the substrate by the refrigerant introduced into the back surface of the substrate in the substrate processing method of the present invention, and to control the substrate temperature to perform the substrate processing.

Further, it is preferable to secure an electrostatic adsorption force which ensures the pressure of the refrigerant required for cooling the back surface of the substrate in the substrate processing method of the present invention.

Further, it is preferable that the back surface of the substrate in the substrate processing method of the present invention cools the refrigerant He gas required.

Furthermore, it is preferable that the RF power (radio frequency power) (applied voltage) to the upper electrode is 0.45 w/cm ² or more and 75 w/ as a condition of substrate processing in the substrate processing method of the present invention. It is below cm ² or is 500 W or more and 2000 W or less.

Furthermore, it is preferable that the RF power (applied voltage) is 500 W or more and 1200 W or less in the substrate processing conditions in the substrate processing method of the present invention.

Further, the substrate-based sapphire substrate in the substrate processing method of the present invention is preferred.

Further, the substrate-based SiC substrate or the compound semiconductor substrate in the substrate processing method of the present invention is preferable.

Furthermore, it is preferable that an insulating film is provided on the substrate in the substrate processing method of the present invention, and the insulating film is a film which is susceptible to electrical influence and is easily charged with electric charges from the plasma.

Further, a film-based photoresist film which is susceptible to electrical properties in the substrate processing method of the present invention is preferred.

Furthermore, it is preferable that the film state on the substrate in the substrate processing method of the present invention is The state of the above-mentioned photoresist film remains in the substrate processing.

The method of manufacturing a semiconductor device of the present invention includes the plasma etching step using the substrate processing method of the present invention, thereby achieving the above object.

In the substrate processing apparatus of the present invention, the substrate is disposed in the processing chamber, and the upper electrode and the lower electrode are independently supplied with electric power, and the processing gas in the processing chamber is plasma-treated to perform substrate processing, and the substrate can be processed in the following state. The substrate processor: only supplies electric power to the upper electrode, and plasma-processes the processing gas supplied to the processing chamber with a higher electron emission rate than the inert gas, so that the substrate is charged The substrate is electrostatically adsorbed on the lower electrode side, thereby achieving the above object.

Hereinafter, the action of the present invention will be described based on the above configuration.

In the present invention, the substrate processing method includes a substrate processing step of disposing the substrate in the processing chamber, supplying electric power independently to the upper electrode and the lower electrode, and plasma-treating the processing gas in the processing chamber to perform substrate processing. The substrate processing method includes a substrate adsorption step in which the substrate gas adsorption step is performed to adjust the pressure of the processing gas supplied to the processing chamber to a specific pressure before the substrate processing step, and the substrate adsorption step supplies power only to the upper electrode. The processing gas supplied into the processing chamber is plasma-formed to charge the substrate to electrostatically adsorb the substrate to the lower electrode side.

Thereby, the area on the insulator substrate is utilized to the maximum extent to increase the number of wafers that can be taken per one substrate, and the process gas pressure adjustment step is also used as the substrate adsorption step, so that the adsorption member can be effectively eliminated. Manufacturing is done to make manufacturing cost-effective.

As described above, according to the present invention, in the processing gas pressure adjusting step of adjusting the pressure of the processing gas supplied into the processing chamber to a specific pressure, only the electric power is supplied to the upper electrode to plasma the processing gas supplied into the processing chamber. The substrate is charged with electricity to electrostatically adsorb the substrate to the lower electrode side, thereby maximizing the effective use of the insulator substrate. The area allows an increase in the number of wafers per one substrate, and the manufacturing member can be efficiently manufactured without additionally requiring an adsorption member, thereby making the manufacturing cost-effective.

1‧‧‧Substrate processing unit

2‧‧‧Processing chamber

3‧‧‧Upper electrode

4‧‧‧ lower electrode

5‧‧‧ Wafer Substrate

6‧‧‧ Plasma

7‧‧‧ESC electrode

11‧‧‧Nitride semiconductor light-emitting elements

12‧‧‧Sapphire substrate

13‧‧‧buffer layer

14‧‧‧Undoped GaN layer

15‧‧‧n type contact layer

16‧‧‧Multiple layers

17‧‧‧Lighting layer of multiple quantum well structure

18‧‧‧Electronic barrier

19‧‧‧p-type contact layer

20‧‧‧Transmissive thin film electrode

21‧‧‧P electrode

22‧‧‧n electrode

23‧‧‧Protective film

100‧‧‧Electrostatic adsorption device

101‧‧‧Insert substrate

102‧‧‧Insulator

103‧‧‧electrode

104‧‧‧Adsorption components

105‧‧‧Substrate support member

200‧‧‧ Plasma processing unit

201‧‧‧Electrostatic suction cup

202‧‧‧electrode

203‧‧‧electrode

204‧‧‧Processing chamber

205‧‧‧Inert gas supply

206‧‧‧Process Gas Supply Department

207‧‧‧Cooling gas supply department

208‧‧‧Exhaust device

209‧‧‧Exhaust pump

210‧‧‧ Lower container

211‧‧‧Exhaust pipe

K‧‧‧Insert substrate

Fig. 1 is a view schematically showing the configuration of a main part of a cross-sectional structure of a substrate processing apparatus according to a first embodiment of the present invention.

Fig. 2 is a view showing the ionization voltage Vi of various gases.

Fig. 3 is a view showing a long period type periodic table of an atom number, an atomic radius (in angstrom), an element symbol, an anion potential, and an ionization potential (unit: kcal/mol).

Fig. 4 is a graph showing the relationship between the ionization potential (kcal/mol) and the ionization voltage Vi of the gas.

Fig. 5 is a graph showing the relationship between the ionization voltage Vi and the ionization potential (kcal/mol) with respect to gases of various gases.

FIG. 6 is a view showing the relationship between the aspect ratio of the uneven shape on the surface of the wafer substrate 5 (sapphire substrate) with respect to the temperature of the wafer substrate 5.

Fig. 7 is a graph showing the relationship between the He leak amount (CC) and the back surface He pressure (KPa) as the pressure dependency of the He leak amount.

Fig. 8 is a view showing the relationship between the temperature of the wafer substrate and the back surface He pressure (KPa) when the temperature of the lower electrode 4 is high.

Fig. 9 is a view showing the relationship between the in-plane temperature of the center and the outer periphery of the wafer substrate with respect to the back surface cooling He pressure (Pa).

Fig. 10 is a vertical cross-sectional view showing an example of a configuration of a main part of a nitride semiconductor light-emitting device according to a second embodiment of the present invention.

Fig. 11 is a schematic view for explaining the principle of electrostatic adsorption of the prior electrostatic adsorption device disclosed in Patent Document 1.

FIG. 12 is a view schematically showing the configuration of a main part of a substrate processing apparatus disclosed in Patent Document 2.

Hereinafter, the first embodiment of the substrate processing method of the present invention and the second embodiment of the method for manufacturing a semiconductor device using the same will be described in detail with reference to the drawings. Further, from the viewpoint of the production of the drawings, the thicknesses, lengths, and the like of the constituent members in FIGS. 1 and 10 are not limited to those shown in the drawings.

(Embodiment 1)

Fig. 1 is a view schematically showing the configuration of a main part of a cross-sectional structure of a substrate processing apparatus according to a first embodiment of the present invention.

In FIG. 1, the substrate processing apparatus 1 according to the first embodiment of the present invention is an ICP (Inductively Coupled Plasma) device, so that the upper electrode 3 and the lower electrode 4 provided in the processing chamber 2 can be independently controlled, and in the lower portion. The wafer substrate 5 on which the insulating substrate is mounted is directly mounted on the electrode 4.

In the substrate processing apparatus 1 of the first embodiment, the wafer substrate 5 is disposed in the processing chamber 2 as the processing chamber, and the upper electrode 3 and the lower electrode 4 are independently supplied with electric power, and the processing in the processing chamber 2 is performed. In the case where the substrate is plasma-treated, the substrate can be processed in such a manner that only the upper electrode 3 is supplied with electric power, and the electron emission rate which is easier to be plasma-pulverized than the inert gas is supplied to the substrate. The processing gas in the processing chamber 2 is plasma-charged, and the wafer substrate 5 is charged with electric charges, and the wafer substrate 5 is electrostatically adsorbed to the lower electrode 4 side.

The substrate processing apparatus 1 controls only the upper electrode 3, ensures that the process reaches the back surface He for cooling of the required pressure, and does not use a mechanical chuck, but utilizes the wafer substrate 5 of the insulating substrate to the maximum extent by electrostatic adsorption. The upper surface area, in which the process gas is introduced, and the inert gas is not introduced into the processing chamber 2 as before, so that the process gas pressure is adjusted to a specific pressure in the process gas pressure adjusting step (stabilization step), and the adsorption retention is set. In the step of adsorbing and holding the plasma 6 by plasma-treating the processing gas, the wafer substrate 5 is electrostatically adsorbed on the lower electrode 4 by the negative charge of the plasma 6 on the wafer substrate 5 and Keep it fixed. Thereafter, the upper electrode 3 and the lower electrode 4 are controlled together. A plasma etching step is performed.

In the adsorption holding step, a gas species having a high electron emission rate is selected as the processing gas. The plasma 6 of the gas type having a high electron emission rate is generated by the RF application of only the upper electrode 3, thereby ensuring sufficient charge supply for securing the adsorption force on the surface of the wafer substrate 5. By applying the ESC voltage of the ESC electrode 7, the charge on the surface of the wafer substrate 5 can be combined to obtain a sufficient adsorption force of the wafer substrate 5 on the surface of the lower electrode 4. The application timing of the ESC voltage of the ESC electrode 7 by the adsorption holding step is started at the beginning of the stabilization step. The substrate adsorption step electrostatically adsorbs the wafer substrate 5 of the insulating substrate by an electrostatic chuck (ESC).

The RF individual control of the upper electrode 3 and the lower electrode 4, the adoption of the ESC method, and the selection of the conditions (gas type, radio frequency power, application timing, etc.) for the electron emission rate of the insulator surface of the wafer substrate 5 are made. In short, a gas type having a high electron emission rate which is easy to be plasma-treated is selected as a processing gas. This will be described using FIG. 2 to FIG. 5.

Fig. 2 is a view showing the ionization voltage Vi of various gases.

The electrons in the plasma 6 are formed by ionization of gas molecules or atoms. Ionization is also caused by the collision of atoms or molecules in an excited state or photoionization by light energy, but most of the direct ionization caused by the collision of accelerated electrons becomes the main one. In order to ionize a gas molecule or atom, it is necessary to acquire a certain level of energy by collision. The lowest energy required for ionization is referred to as the ionization voltage Vi, as shown in Fig. 2, depending on the type of gas. It can be seen that the ionization voltage Vi of a rare gas such as He or Ar is relatively high, being 10V to 20V, and the ionization voltage Vi of the alkali metal is low, being 3V to 4V, and thus is easily ionized.

Fig. 3 is a view showing a long period type periodic table of an atom number, an atomic radius (in angstrom), an element symbol, an anion potential, and an ionization potential (unit: kcal/mol).

As shown in FIG. 3, the plural elements can be classified into non-metal elements, metal elements, semi-metal elements, and rare gas elements. Among them, the element symbol is a slanted font and is a gas at normal temperature. The non-metallic elements of the gas at normal temperature are H, N, O, F, and Cl. N is not used as an etching gas. The elements with lower ionization potential (in kcal/mol) are O, F, and Cl. Therefore, the type of gas which is used for the plasma etching treatment gas and which has a high electron emission rate which is easy to be pulverized may be a processing gas containing a non-metal element O and Cl having a low ionization potential.

Further, since a rare gas element does not form a compound, the negative electrical properties thereof are not described herein.

Fig. 4 is a graph showing the relationship between the ionization potential (kcal/mol) and the ionization voltage Vi of the gas.

In FIG. 4, the ionization voltage Vi of the gas is correlated with the ionization potential (kcal/mol). In short, the lower the ionization potential (kcal/mol), the more linear the ionization voltage Vi of the gas will be, and the higher the electron emission rate of the plasma-producing ion is, the lower the ionization potential, and the gas The treatment gas is also low in ionization voltage Vi. When the ionization potential is low, it is easier to ionize with a low voltage (applied voltage).

Fig. 5 is a graph showing the relationship between the ionization voltage Vi and the ionization potential (kcal/mol) with respect to gases of various gases.

In Fig. 5, the gas having a lower ionization potential (kcal/mol) is more ionized, and thus the electrostatic adsorption is good. Specifically, the gases O ₂ , O and Cl are excellent in electrostatic adsorption. Examples of the processing gas containing Cl include Cl ₂ (chlorine), SiCl ₄ (cerium tetrachloride), and BCl ₃ (boron trichloride). A layer such as a GaN layer may be etched by using Cl ₂ (chlorine) or SiCl ₄ (ruthenium tetrachloride) as a processing gas. BCl ₃ (boron trichloride) can be used as a processing gas for etching treatment to form a surface uneven shape of a sapphire substrate or the like.

Fig. 6 is a view showing the temperature dependence of the wafer substrate on the aspect ratio of the surface of the wafer substrate 5.

In FIG. 6, the aspect ratio of the uneven shape of the surface of the wafer substrate 5 (sapphire substrate) varies depending on the temperature of the wafer substrate 5, and therefore, in order to obtain the aspect ratio of the uneven shape of the surface of the sapphire substrate required, it is necessary to set The temperature of the wafer substrate 5. Wafer substrate 5 temperature The influence of the pressure of the back surface He of the temperature of the lower electrode 4 when the temperature of the lower electrode 4 is warped with the wafer substrate 5 is affected.

Fig. 7 is a graph showing the relationship between the He leak amount (CC) and the back surface He pressure (KPa) as the pressure dependency of the He leak amount.

In Fig. 7, the larger the back He pressure (KPa), the more the back surface He leaks. The larger the amount of warpage of the wafer substrate 5, the larger the amount of leakage of the back surface He. When the amount of leakage increases, the wafer substrate 5 cannot be cooled for control to a specific temperature. As described above, if the amount of leakage increases, the wafer substrate 5 cannot be controlled to a desired temperature, and thus the aspect ratio of the embossed uneven shape does not change to a desired aspect ratio. In order to prevent this, the amount of leakage of the back surface He is suppressed by securing the adsorption force, and the uniformity of the in-plane temperature is improved, whereby the shape tolerance of the embossed uneven shape is also improved.

Fig. 8 is a view showing the relationship between the temperature of the wafer substrate and the back surface He pressure (KPa) when the temperature of the lower electrode 4 is high.

In Fig. 8, the higher the back He pressure (KPa), the lower the temperature of the substrate to be processed. It is shown that the temperature of the lower electrode 4 is 35 degrees Celsius and the temperature of the lower electrode 4 is 55 degrees Celsius. The higher the pressure of the back surface He, the lower the temperature as the wafer substrate 5. However, in order to obtain the desired uneven shape, it is necessary to control the temperature of the wafer substrate 5 required.

Fig. 9 is a view showing the relationship between the in-plane temperature of the center and the outer periphery of the wafer substrate with respect to the back surface cooling He pressure (Pa).

In FIG. 9, the higher the back surface cooling He pressure (Pa) of the center portion (Center) and the outer peripheral portion (Top) of the wafer substrate 5, the more uniform the temperature of the wafer substrate 5. As described above, it is understood that the uniformity of the in-plane temperature of the wafer substrate 5 is improved with an increase in the back surface cooling He pressure (Pa).

As described above, the substrate processing method according to the first embodiment includes a substrate processing step of disposing the wafer substrate 5 in the processing chamber 2 as a processing chamber. Internally, the upper electrode 3 and the lower electrode 4 are independently supplied with electric power, and the processing gas in the processing chamber 2 is plasma-treated to perform substrate processing, and the substrate processing method is performed before the substrate processing step of the plasma etching process. The processing gas pressure adjusting step (stabilizing step) for adjusting the pressure of the processing gas supplied into the processing chamber 2 to a specific pressure includes a substrate adsorption step of supplying power only to the upper electrode 3 and supplying it to the processing. The processing gas in the chamber 2 is plasma-charged, and the wafer substrate 5 is charged, and the wafer substrate 5 is electrostatically adsorbed to the lower electrode 4 side. In this case, a gas type having a high electron emission rate is selected as the processing gas to be used.

In this way, by using the stabilization step before the plasma etching treatment as the substrate adsorption step, it is possible to avoid an additional step of the substrate adsorption step as before, resulting in an increase in unnecessary steps and an unexpected plasma etching, thereby being more effective. Substrate processing such as plasma etching treatment is performed.

As the processing gas, an adsorption gas containing an element having an ionization potential of 320 kcal/mol or less is used. The processing gas is a gas for adsorption, and is a gas containing at least one of O (oxygen) and Cl (chlorine) gases.

In the substrate adsorption step, the substrate is an insulating substrate, and the wafer substrate 5 of the insulating substrate is electrostatically adsorbed by an electrostatic chuck (ESC).

The substrate is cooled by cooling the substrate introduced onto the back surface of the wafer substrate 5, and the substrate temperature is controlled to perform substrate processing. It is necessary to ensure the electrostatic adsorption force of the pressure of the refrigerant required to ensure the back surface of the wafer substrate 5 to be cooled. He gas is used as a refrigerant required for cooling the back surface of the wafer substrate 5.

As the plasma etching process (substrate processing) of the condition, the upper electrode 3 to the RF power (applied voltage) is ² or more and ² or less, or less than 500W and 2000W 0.45w / cm 75w / cm. More preferably, the RF power (applied voltage) is 500 W or more and 1200 W or less as a condition of substrate processing. The RF power of 1200W~2000W is the current maximum output RF power.

Here, a sapphire substrate is used as the wafer substrate 5, but it may be a SiC substrate or a SiC substrate. Compound semiconductor substrate. When a film which is easily provided with an insulating film derived from a charge of plasma and which is easily affected by electrical properties is provided on the wafer substrate 5, the electrostatic adsorption force is good. As a film which is susceptible to electrical influence, there is a photoresist film or the like. Further, in order to maintain the electrostatic adsorption force, the film state on the wafer substrate 5 is preferably such that a photoresist film remains in the substrate processing.

As described above, the use of a mechanical jig or the like causes a loss in the number of available wafer boundaries, and therefore ESC is necessary in order to maximize the effective use of the surface area of the wafer substrate 5. In the substrate adsorption step, the wafer substrate 5 is an insulating substrate, and the insulating substrate is electrostatically adsorbed by an electrostatic chuck (ESC).

The material of the wafer substrate 5 is an insulator and is a material that is difficult to be electrically adsorbed. Therefore, since the electrostatic chuck (ESC) is used, since the adsorption force is ensured, the wafer substrate 5 is sufficiently charged with the electric charge from the plasma 6. And the gas type with high electron emission rate which is easy to be pulverized is selected as the processing gas. The gas type having a high electron emission rate which is easy to be ionized is a processing gas having a low ionization potential and a low ionization voltage Vi of the gas.

In order to ensure process performance improvement or process stabilization such as aspect ratio control of the uneven shape, that is, in-plane uniformity, sufficient substrate temperature control cooling power required to ensure tolerance, not only the mounting of the wafer substrate 5 is required. The electrode temperature, and a certain amount of back He pressure, is required to transfer this temperature.

Here, various tests are performed on the 6-inch wafer substrate 5, and the warpage of the wafer substrate 5 is also increased with the increase in diameter in the future. As the warpage of the wafer substrate 5 increases, the sealing of the back surface He becomes difficult, and the amount of He leakage also increases.

In order to secure the adsorption force of the electrostatic chuck (ESC), it is necessary to have more charge on the surface of the wafer substrate 5. The charge on the surface of the wafer substrate 5 is more dependent on the element species having a lower ionization potential and a lower ionization voltage Vi of the gas.

(Embodiment 2)

In the first embodiment, the substrate processing apparatus and the substrate processing method using the same are described. In the second embodiment, the details will be described with reference to the drawings. A method of manufacturing a semiconductor device using a plasma etching step of the substrate processing method is applied to a method of manufacturing a nitride semiconductor light-emitting device.

Fig. 10 is a vertical cross-sectional view showing an example of a configuration of a main part of a nitride semiconductor light-emitting device according to a second embodiment of the present invention.

In the nitride semiconductor light-emitting device 11 of the second embodiment, for example, on a sapphire substrate 12 having a substrate having a thickness of about 1300 μm on the surface, an aluminum nitride (AlN) film is formed. The buffer layer 13 having a film thickness of about 15 nm. An undoped GaN layer 14 containing undoped GaN having a film thickness of about 500 nm is formed on the buffer layer 13. The single crystal substrate includes the sapphire substrate 12, the buffer layer 13, and the undoped GaN layer 14.

Further, in the nitride semiconductor light-emitting device 11 of the first embodiment, a film thickness of GaN containing bismuth (Si) doped with 1 × 10 ¹⁸ /cm ³ is formed on the single crystal substrate to be about 5 μm. N-type contact layer 15 (high carrier concentration n ⁺ layer). A plurality of layers 16 are formed on the n-type contact layer 15, and a light-emitting layer 17 of a multiple quantum well structure is formed on the multiple layers 16.

In the multiple layer 16, a plurality of layers including In _x Ga _1-x N (0 < x < 0.3) and a second layer containing GaN are alternately laminated. Here, in the multiple layer 16, for example, five pairs of a first layer including In _0.03 Ga _0.97 N having a film thickness of 3 nm and a second layer including GaN having a film thickness of 20 nm are laminated.

In the first layer of the multiple layers 16, Si is added as a conductive impurity, and the concentration thereof is 5 × 10 ¹⁶ cm ^-3 to 1 × 10 ¹⁸ cm ^-3 (more preferably 1 × 10 ^17). In the range of cm ^-3 to 1 × 10 ¹⁸ cm ^-3 ), the electrostatic breakdown energy (mJ/cm ² ) which the luminescent layer 17 receives is 20 or more and 40 or less (more preferably 20 or more and 35 or less).

Specifically, the relationship between the electrostatic breakdown energy (mJ/cm ² ) received by the light-emitting layer 17 and the Si concentration in the first layer of the multiple layers 16 is represented by the reverse electrical characteristic (reverse current) of the specific item as a parameter. In the curve, the concentration of Si corresponding to the minimum value of the electrostatic breakdown energy (mJ/cm ² ) is set.

The well layer of the light-emitting layer 17 of the multiple quantum well structure contains In _y Ga _1-y N (0 ≦ y < 0.3) containing at least In. As described above, in the light-emitting layer 17 of the multiple quantum well structure, for example, three pairs of well layers including In _0.2 Ga _0.8 N having a film thickness of 3 nm and a barrier layer containing GaN having a film thickness of 20 nm are laminated.

Further, in the nitride semiconductor light-emitting device 11 of the second embodiment, p-type Al _0.15 Ga _0.85 including a film doped with 2 × 10 ¹⁹ /cm ³ of Mg and having a film thickness of 25 nm is formed on the light-emitting layer 17 . The p-type layer of N is the electron blocking layer 18. On the electron blocking layer 18, a p-type contact layer 19 containing p-type GaN doped with 8 × 10 ¹⁹ Mg and having a film thickness of 100 nm was formed.

On the p-type contact layer 19, a light-transmissive thin film electrode 20 (ITO, Indium Tin Oxide, indium tin oxide) which is formed by metal deposition is formed. A p-electrode 21 is formed on a portion of the translucent thin film electrode 20.

On the other hand, the end portion of the n-type contact layer 15 is exposed to the middle, and the n-electrode 22 is formed thereon. On the uppermost portion of the p-electrode 21 and the n-electrode 22, a protective film 23 containing a SiO ₂ film as a Si _x O _y film for humidity resistance or the like is formed.

The protective film 23 is formed on the exposed surfaces of the translucent film electrode 20, the p-electrode 21, the n-electrode 22, and the n-type contact layer 15, and is formed on the plurality of layers 16 to the end of the end portion of the n-type contact layer 15, The luminescent layer 17, the electron blocking layer 18, the p-type contact layer 19, and the translucent thin film electrode 20 (ITO) are etched away on the side surface.

In this manner, the protective film 23 covers the p-electrode 21, the n-electrode 22, and the surface of the element for protection. Protective film 23 may be a single layer structure of SiO ₂ film, it may also be used as SiN Si _x N _y film of the film, on which the two-layer structure as membrane ₂ Si _x O SiO _y of the film. Further, also upside down, as a Si _x O SiO _y film of the film _2, on which the two-layer structure as SiN Si _x N _y film of the film. In such cases, the SiN film functions as a passivation film.

In short, the protective film 23 contains at least a Si _x O _y film of a Si _x O _y film, a Si _x N _y film, and a Si _x O _y N _z film.

Next, a method of manufacturing the nitride semiconductor light-emitting device 11 having the above configuration will be described. Bright.

As shown in FIG. 10, the method for manufacturing the nitride semiconductor light-emitting device 11 of the second embodiment includes a substrate housing step of the sapphire substrate 12, wherein the sapphire substrate 12 is housed at a specific position, and a surface unevenness processing step is performed on the sapphire. The surface of the substrate 12 is formed with irregularities at a specific aspect ratio; a MOCVD (Metal Organic Chemical Vapor Deposition) step is performed on the surface of the sapphire substrate 12 by the MOCVD method, in order Forming a buffer layer 13, an undoped GaN layer 14, an n-type contact layer 15, a multiple layer 16, a light-emitting layer 17 of a multiple quantum well structure, an electron blocking layer 18, and a p-type contact layer 19; a transparent electrode forming step A transparent thin film electrode 20 is formed on the p-type contact layer 19; an electrode forming step of the p-electrode 21 and the n-electrode 22 is performed by etching the end portion of the substrate to the middle of the n-type contact layer 15 to form an n-type contact layer. The end portion of the 15 is exposed halfway, an n-electrode 22 is formed on the end surface of the n-type contact layer 15, and a p-electrode 21 is formed on a surface of a portion of the translucent thin film electrode 20; a protective film forming step a protective film 23 for moisture resistance or the like is formed on the exposed surfaces of the transparent thin film electrode 20, the p-electrode 21, the n-electrode 22, and the n-type contact layer 15, and further, an electrode opening portion is formed on the etching removal side surface; The protective film 23 on the p electrode 21 and the n electrode 22 is opened, respectively.

In the method of manufacturing the nitride semiconductor light-emitting device 11 as a method of manufacturing a semiconductor device, the surface unevenness processing step of forming the unevenness on the surface of the sapphire substrate 12 and the etching of the substrate end portion to the n-type contact layer 15 are performed. In the etching step in which the end portion of the n-type contact layer 15 is exposed in the middle, the substrate processing method according to the first embodiment described above is used to accurately perform a more excellent plasma etching treatment. In the manufacturing method of the nitride semiconductor light-emitting device 11, the substrate processing method using the above-described first embodiment is included in the processing gas pressure adjusting step of adjusting the pressure of the processing gas supplied into the processing chamber 2 to a specific pressure. In the plasma etching step, in the substrate processing method according to the first embodiment, only the electric power supplied to the processing chamber 2 is plasma-charged to the upper electrode 3, and the wafer substrate 5 is charged and the crystal is charged. The circular substrate 5 is electrostatically adsorbed to the lower electrode 4 side.

Therefore, in the method of manufacturing the nitride semiconductor light-emitting device 11 of the second embodiment, in the plasma etching step, the area on the insulator substrate can be utilized to the maximum extent, and the number of wafers that can be obtained per one substrate can be increased. Moreover, the adsorption member can be effectively manufactured without additional need for manufacturing, thereby making the manufacturing cost-effective.

In the second embodiment, a method of manufacturing the nitride semiconductor light-emitting device 11 of an LED (light emitting diode) has been described. However, the present invention is not limited thereto, and the first embodiment is used as described above. The method of manufacturing the semiconductor device in the plasma etching step of the substrate processing method may be used.

The present invention has been exemplified as described above using the preferred embodiments 1 and 2 of the present invention, but the present invention is not limited to the first and second embodiments. It is to be understood that the invention is to be construed as limited only by the scope of the claims. The present invention can be understood from the description of the preferred embodiments 1 and 2 of the present invention, and equivalents can be made according to the description of the present invention and the technical knowledge. The patents, patent applications, and documents cited in the present specification are to be understood as being specifically described in the specification.

[Industrial availability]

The substrate processing apparatus used for electrostatically adsorbing and fixing a substrate to be processed, and performing specific processing such as plasma dry etching on the substrate to be processed, and a substrate processing method using the same, and a method of manufacturing the semiconductor device using the same In the process gas pressure adjustment step of adjusting the pressure of the processing gas supplied to the processing chamber to a specific pressure, only the electric power is supplied to the upper electrode to plasma the processing gas supplied into the processing chamber, so that the substrate is provided with The electric charge electrostatically adsorbs the substrate to the lower electrode side, so that the area on the insulator substrate can be utilized to the maximum extent, and the number of wafers that can be obtained per one substrate can be increased, and the manufacturing member can be efficiently manufactured without additionally requiring an adsorption member. Thereby making the manufacturing cost-effective.

1‧‧‧Substrate processing unit

2‧‧‧Processing chamber

3‧‧‧Upper electrode

4‧‧‧ lower electrode

5‧‧‧ Wafer Substrate

6‧‧‧ Plasma

7‧‧‧ESC electrode

Claims (6)

A substrate processing method comprising a substrate processing step of disposing a substrate in a processing chamber, separately supplying electric power to the upper electrode and the lower electrode, and plasma-treating the processing gas in the processing chamber to perform a substrate Processing, and the substrate processing method includes a substrate adsorption step in the process gas pressure adjustment step of adjusting the pressure of the processing gas supplied to the processing chamber to a specific pressure before the substrate processing step, wherein the substrate adsorption step is only The upper electrode supplies electric power, and plasmas the processing gas supplied into the processing chamber, and charges the substrate to electrostatically adsorb the substrate on the lower electrode side. The substrate processing method according to claim 1, wherein a gas species having a higher electron emission rate which is easier to be plasma-pulverized than the inert gas is selected as the processing gas. The substrate processing method of claim 2, wherein the processing gas system contains a gas of at least one of O (oxygen) and Cl (chlorine). The substrate processing method of claim 1, which secures an electrostatic adsorption force which ensures the pressure of the refrigerant required for cooling the back surface of the substrate. A method of fabricating a semiconductor device, comprising a plasma etching step using the substrate processing method according to any one of claims 1 to 4. A substrate processing apparatus for arranging a substrate in a processing chamber, supplying electric power independently to the upper electrode and the lower electrode, and plasma-treating the processing gas in the processing chamber to perform substrate processing, and the substrate can be implemented in the following state Processing: only supplying electric power to the upper electrode, and plasma-treating the processing gas supplied to the processing chamber with a higher electron emission rate than the inert gas, so that the substrate is charged and the substrate is electrostatically charged. Adsorbed to the lower electrode side.