Low-concentration ozone gas supply device

Abstract

The invention relates to a low-concentration ozone gas supply device which is used for supplying low-concentration ozone gas to one or more reaction cavities and comprises an ozone dilution tank, an ozone generator, a diluted gas supply device and a plurality of gas pressure storage barrels. A dilution space is formed in the ozone dilution tank, and the ozone dilution tank is provided with an overflow port communicated with the dilution space. The ozone generator is used for continuously supplying ozone to the dilution space of the ozone dilution tank. The dilution gas supplier is used for supplying dilution gas to the dilution space, so that ozone and the dilution gas are mixed in the dilution space to form low-concentration ozone gas, and the low-concentration ozone gas in the dilution space continuously overflows from the overflow port. The plurality of gas pressure storage barrels are connected to the dilution space; the volume of the dilution space is larger than the sum of the volumes of the gas pressure storage barrels.

Description

Technical Field

[0001] The invention relates to an ozone supply in a semiconductor process, in particular to a low-concentration ozone gas supply device. Background Art

[0002] Ozone gas is often used in CVD / ALD processes, especially for cleaning the surface of wafers to remove contaminants on the surface of wafers. However, in some processes, there are sometimes important functional groups on the surface of wafers or powders that need to be used in subsequent processes. These functional groups are easily destroyed by reaction with ozone. At this time, it is necessary to pass ozone at a lower concentration into the reaction chamber to avoid damage to the functional groups.

[0003] The ozone dilution is to connect the ozone generator in parallel with the dilution gas (O2 or Ar) supply source, and control the output of the dilution gas through a mass flow controller, so that the ozone is diluted by the dilution gas to produce low-concentration ozone gas. However, the flow rate and concentration of the low-concentration ozone gas of this mechanism are prone to instability, making it difficult to control the ozone effect in the reaction chamber. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a low-concentration ozone gas supply device for stably providing low-concentration ozone gas to one or more reaction chambers.

[0005] The present invention proposes a low-concentration ozone gas supply device for providing low-concentration ozone gas to one or more reaction chambers, comprising an ozone dilution tank, an ozone generator, a dilution gas supplier, and a plurality of gas pressure storage tanks. The ozone dilution tank has a dilution space inside, and the ozone dilution tank has an overflow port connected to the dilution space. The ozone generator is used to continuously supply ozone to the dilution space of the ozone dilution tank. The dilution gas supplier is used to supply dilution gas to the dilution space, so that ozone and dilution gas are mixed in the dilution space to form low-concentration ozone gas, and the low-concentration ozone gas in the dilution space continuously overflows from the overflow port. The plurality of gas pressure storage tanks are connected to the dilution space; wherein the volume of the dilution space is greater than the sum of the volumes of the gas pressure storage tanks.

[0006] Preferably, the ozone dilution tank further includes an ozone receiving port, and the ozone generator is connected to the ozone receiving port.

[0007] Preferably, the ozone generator is connected to an oxygen source for receiving oxygen, and a high voltage electric field is provided inside the ozone generator to convert oxygen into ozone.

[0008] Preferably, the ozone dilution tank further includes a dilution gas receiving port, and the dilution gas supplier is connected to the dilution gas receiving port.

[0009] Preferably, according to the ozone mass flow rate provided by the ozone generator, the dilution gas supplier supplies the dilution gas to the dilution space at a predetermined mass flow rate, so that the weight percentage of ozone in the low-concentration ozone gas in the dilution space is lower than 10% by weight.

[0010] Preferably, the dilution gas supplier comprises a dilution gas source and a mass flow controller, the dilution gas source is used to supply the dilution gas, and the mass flow controller is connected to the dilution gas source to control the mass flow of the dilution gas flowing from the dilution gas source into the dilution space.

[0011] Preferably, the degassing gas is oxygen, the dilution gas source of the dilution gas supplier is an oxygen source, and the ozone generator receives oxygen from the oxygen source.

[0012] Preferably, the ozone dilution tank is provided with an ozone pressure gauge for monitoring the pressure in the dilution space to adjust the flow of ozone and dilution gas.

[0013] Preferably, the volume of the dilution space is greater than the sum of the volumes of the gas pressure accumulator tanks plus the sum, and the sum is greater than 10% of the sum.

[0014] Preferably, each gas pressure storage tank is connected to a corresponding reaction chamber by an ozone supply pipeline to supply low-concentration ozone gas to the corresponding reaction chamber, and the volume of each gas pressure storage tank and the length of each corresponding ozone supply pipeline are the same.

[0015] Through the low-concentration ozone gas supply device proposed in the present invention, ozone and dilution gas system are first fully mixed in the ozone dilution tank to form low-concentration ozone gas, and then the gas pressure storage tank is pressurized with the low-concentration ozone gas. The pressure storage of the gas pressure storage tank can ensure that the low-concentration ozone gas injected into the reaction chamber maintains a stable concentration and flow rate, so that the process conditions in the reflection chamber (such as wafer cleaning time and temperature) are easier to control and maintain good process effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the pipeline design of a low-concentration ozone gas supply device and multiple reaction chambers in an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of the pipeline design of a low-concentration ozone gas supply device in an embodiment of the present invention.

[0018] Figure 3 It is a schematic diagram of the pipeline design of a low-concentration ozone gas supply device in an embodiment of the present invention.

[0019] Figure 4 It is a schematic diagram of the pipeline design of a low-concentration ozone gas supply device in an embodiment of the present invention.

[0020] Figure 5 It is a schematic diagram of the pipeline design of a low-concentration ozone gas supply device in an embodiment of the present invention.

[0021] Figure 6 It is a schematic diagram of the pipeline design of a low-concentration ozone gas supply device in an embodiment of the present invention.

[0022] Explanation of the reference numerals: 100 - low concentration ozone gas supply device; 110 - ozone dilution tank; 120 - ozone generator; 130 - dilution gas supplier; 141, 142, 143 - gas pressure storage tanks; 200 - reaction chamber; 112 - ozone receiving port; 114 - dilution gas receiving port; 116 - overflow port; 132 - mass flow controller; CT - cold trap; G1 - ozone pressure gauge; G2 - vacuum pressure gauge; G3 - chamber pressure gauge; S1 - oxygen source; S2 - argon source; S3 - trimethylaluminum gas source; S4 - nitrogen source; P1, P2 - vacuum pump; V1 - pressure relief valve; V2 - inlet valve; V3 - outlet valve; V4, V5 - gas valve; V6, V7 - shut-off valve. DETAILED DESCRIPTION

[0023] See also Figure 1 and Figure 2 As shown, a low-concentration ozone gas supply device 100 disclosed in an embodiment of the present invention comprises an ozone dilution tank 110, an ozone generator 120, a dilution gas supplier 130, and a plurality of gas pressure storage tanks 141, 142. The low-concentration ozone gas supply device 100 is used to provide low-concentration ozone gas with stable pressure and flow to one or more reaction chambers 200.

[0024] like Figure 1 and Figure 2 As shown, the ozone dilution tank 110 has a dilution space inside, and the ozone dilution tank 110 has an ozone receiving port 112, a dilution gas receiving port 114 and an overflow port 116, which are respectively connected to the dilution space.

[0025] like Figure 1 and Figure 2 As shown, the ozone generator 120 is connected to the ozone receiving port 112 for continuously supplying ozone to the dilution space of the ozone dilution tank 110. Specifically, the ozone generator 120 is connected to the oxygen source S1 for receiving oxygen (O2). The ozone generator 120 provides a high voltage electric field through the electrode plate inside, so that the oxygen molecules are dissociated into individual oxygen atoms, and the individual oxygen atoms are combined with oxygen molecules to form ozone molecules (O3).

[0026] like Figure 1 and Figure 2As shown, the dilution gas supplier 130 is connected to the dilution gas receiving port 114 for supplying the dilution gas to the dilution space. The dilution gas is mixed with ozone in the dilution space to generate low-concentration ozone gas. According to the mass flow rate of ozone provided by the ozone generator 120, the dilution gas supplier 130 supplies the dilution gas to the dilution space at a predetermined mass flow rate, so that the ozone weight percentage concentration (wt%) in the low-concentration ozone gas in the dilution space can be maintained at a predetermined concentration, for example, an ozone weight percentage concentration of less than 10%, but not limited to less than 10%.

[0027] like Figure 1 and Figure 2 As shown, the dilution gas supplier 130 includes a dilution gas source and a mass flow controller 132. The dilution gas source is used to supply dilution gas. The mass flow controller 132 is connected to the dilution gas source and the dilution gas receiving port 114 to control the mass flow of the dilution gas flowing from the dilution gas source into the dilution space.

[0028] like Figure 1 and Figure 2 As shown, the dilution gas may be oxygen (O2) or argon (Ar). When the dilution gas is oxygen (O2), the ozone generator 120 and the dilution gas supplier 130 may share the oxygen source S1, that is, the oxygen source S1 is also the dilution gas source of the dilution gas supplier 130. That is, the oxygen source S1 provides oxygen to the ozone generator 120, and the mass flow controller is also connected to the oxygen source S1 to use the oxygen provided by the oxygen source S1 as the dilution gas.

[0029] like Figure 3 As shown, when the dilution gas is argon (Ar), the mass flow controller 132 is connected to the argon source S2, and the argon source S2 is used as the dilution gas source. Figure 3 The argon source in the embodiment can be replaced by other types of gas sources, as long as they are not easily reacted with ozone and do not affect the surface characteristics of the wafer. The argon source S2 can also be another oxygen source, that is, the ozone generator 120 and the dilution gas supplier 130 are each connected to different oxygen sources, and do not share a single oxygen source S1.

[0030] like Figure 2 and Figure 3As shown, specifically, the ozone generator 120 continuously supplies ozone to the dilution space of the ozone dilution tank 110, the dilution gas supplier 130 continuously supplies dilution gas to the dilution space of the ozone dilution tank 110, and the low-concentration ozone gas in the dilution space also continuously overflows from the overflow port 116 to the ozone dissociation tank D, so that the low-concentration ozone gas is in a continuous replenishment and overflow flow state in the ozone dilution tank 110, so as to maintain the concentration and pressure of the low-concentration ozone gas. It should be noted that the ozone generator 120 does not supply pure ozone gas, but supplies a mixed gas of ozone and oxygen.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, the ozone dilution tank 110 is provided with an ozone pressure gauge G1. The ozone pressure gauge G1 is used to monitor the pressure in the dilution space to adjust the flow of ozone and dilution gas, and ensure that the pressure in the dilution space is greater than the pressure of the ozone dissociation tank R3 and the gas pressure storage tanks 141, 142, to prevent the gas from flowing back from the overflow port 116 and / or the gas pressure storage tanks 141, 142 and contaminating the low-concentration ozone gas. The overflow port 116 can also be provided with a pressure relief valve V1, which opens when the pressure is greater than a predetermined value and closes when the pressure is less than a predetermined value, which can also prevent the external gas from flowing back from the overflow port 116 to the dilution space.

[0032] like Figure 1 , Figure 2 and Figure 3 As shown, a plurality of gas pressure accumulators 141, 142 are respectively connected to the dilution space of the ozone dilution tank 110 through an inlet valve V2 to receive low-concentration ozone gas from the dilution space. The inlet valve V2 can be closed in time to prevent the gas from flowing back to the dilution space through the pipeline. Specifically, the volume of the dilution space is greater than the sum of the volumes of the plurality of gas pressure accumulators 141, 142 to ensure that the ozone dilution tank 110 can supply low-concentration ozone gas with sufficient pressure to the gas pressure accumulators 141, 142 at any time. Preferably, the volume of the dilution space is greater than the sum of the volumes of the plurality of gas pressure accumulators 141, 142 plus the sum. The addition may be 10%, 20% or more of the total.

[0033] like Figure 1As shown, each gas pressure accumulator 141, 142 is connected to a corresponding reaction chamber 200 by an ozone supply pipeline 150 to supply low-concentration ozone gas to the corresponding reaction chamber 200. The ozone supply pipeline 150 may be provided with an outlet valve V3, located between the reaction chamber and the corresponding gas pressure accumulator 141, 142. The outlet valve V3 is used to timely open or close the low-concentration ozone gas supplied to the reaction chamber 200. That is, by selectively opening or closing a plurality of outlet valves V3, low-concentration ozone gas can be supplied to each reaction chamber 200 at the same time, or low-concentration ozone gas can be supplied to only individual reaction chambers 200.

[0034] In addition, the volume size of the gas pressure accumulator barrels 141, 142 and the length of the corresponding ozone supply pipeline 150 will affect the concentration and flow rate of ozone. In order to make the ozone concentration and flow rate received by each reaction chamber 200 consistent, the volume size of the gas pressure accumulator barrels 141, 142 and the length of the corresponding ozone supply pipeline 150 must be the same. The middle section of the ozone supply pipeline 150 can also be bypassed to the vacuum pump P1. Before starting to supply low-concentration ozone gas, the inlet valve V2 and the outlet valve V3 can be closed first, and the vacuum pump P1 can be started to exhaust the residual gas inside the gas pressure accumulator barrels 141, 142.

[0035] When the low-concentration ozone gas is supplied, the outlet valve V3 may be closed first, and when the pressure of the low-concentration ozone gas in the gas pressure storage tanks 141, 142 is filled to be consistent with the pressure of the ozone dilution tank 110, the outlet valve V3 may be opened to ensure that the concentration and flow rate of the ozone supplied to each reaction chamber 200 are stable.

[0036] like Figure 4 As shown, the two gas pressure storage tanks 141 and 142 are only for illustration. In fact, there may be more than two, for example, three gas pressure storage tanks 141, 142, 143. Each gas pressure storage tank 141, 142, 143 is connected to a respective reaction chamber 200.

[0037] like Figure 1As shown, the reaction chamber 200 can also be connected to different working gases through gas valves V4 and V5 for subsequent CVD / ALD processes. For example, the gas valve V4 can be connected to a trimethylaluminum (TMA) gas source S3 to allow the reaction chamber 200 to receive TMA gas; the gas valve V5 can be connected to a nitrogen source S4 to allow the reaction chamber 200 to receive nitrogen. The reaction chamber 200 can also be connected to a vacuum pump P2 to evacuate the reaction chamber 200 and maintain a low pressure inside the reaction chamber 200. A cold trap CT can be set between the reaction chamber 200 and the vacuum pump P2 to collect substances with high condensation points in the gas. A vacuum pressure gauge G2 can be set between the cold trap CT and the vacuum pump P2 to monitor the pressure changes after the vacuum pump P2 is operated. A closing valve V6 can be set between the cold trap CT and the vacuum pump P2 to close the pipeline when the vacuum pump P2 stops operating. The reaction chamber 200 may also be connected to a chamber pressure gauge G3 via a closing valve V7 to monitor the pressure inside the reaction chamber 200 .

[0038] like Figure 5 As shown, when the ozone generation amount of the ozone generator 120 is insufficient, the low-concentration ozone gas supply device 100 may include a plurality of ozone generators 120, which are connected to the ozone dilution tank 110 respectively, or connected to the ozone dilution tank 110 in parallel to ensure sufficient ozone supply.

[0039] like Figure 5 As shown, when the ozone generation amount of the ozone generator 120 is insufficient, the low-concentration ozone gas supply device 100 may include a plurality of ozone generators 120, which are connected to the ozone dilution tank 110 respectively, or connected to the ozone dilution tank 110 in parallel to ensure sufficient ozone supply.

[0040] like Figure 6 As shown, when the capacity of the ozone dilution tank 110 is insufficient, for example, the capacity of a single ozone dilution tank 110 is less than the sum of the volumes of the multiple gas pressure storage tanks 141, 142, or the volume of the dilution space is less than the sum of the volumes of the multiple gas pressure storage tanks 141, 142, the low-concentration ozone gas supply device 100 may include multiple ozone dilution tanks 110. The multiple ozone dilution tanks 110 are interconnected to balance the pressure and concentration of the ozone gas. The multiple ozone dilution tanks 110 can be arranged in series, with a single ozone dilution tank 110 receiving ozone and dilution gas, and a single ozone dilution tank 110 outputting low-concentration ozone gas. The multiple ozone dilution tanks 110 can be arranged in parallel, with ozone and dilution gas being injected into the multiple ozone dilution tanks 110 at the same time, and the low-concentration ozone gas output by the multiple ozone dilution tanks 110 is merged through a manifold and then divided to each gas pressure storage tank 141, 142.

[0041] Through the low-concentration ozone gas supply device 100 proposed by the present invention, ozone and dilution gas system are first fully mixed into low-concentration ozone gas in the ozone dilution tank 110, and then the low-concentration ozone gas is used to pressurize the gas pressure storage barrels 141 and 142. The pressure storage of the gas pressure storage barrels 141 and 142 can ensure that the low-concentration ozone gas injected into the reaction chamber maintains a stable concentration and flow rate, so that the process conditions in the reflection chamber (such as wafer cleaning time and temperature) are easier to control and maintain good process effects.

[0042] The above is only one embodiment of the present invention and is not intended to limit the scope of the present invention. That is, all equivalent changes and modifications to the shape, structure, characteristics and spirit described in the claims of the present invention should be included in the scope of protection requested by the present invention.

Claims

1. A low-concentration ozone gas supply device for providing low-concentration ozone gas to one or more reaction chambers, characterized in that: include: An ozone dilution tank having a dilution space therein, and the ozone dilution tank having an overflow port connected to the dilution space; an ozone generator, used for continuously supplying ozone to the dilution space of the ozone dilution tank; a dilution gas supplier, used for supplying dilution gas to the dilution space, so that the ozone and the dilution gas are mixed in the dilution space to form the low-concentration ozone gas, and the low-concentration ozone gas in the dilution space continuously overflows from the overflow port; and A plurality of gas pressure storage tanks are connected to the dilution space to receive the low-concentration ozone gas respectively; wherein the volume of the dilution space is greater than the sum of the volumes of the plurality of gas pressure storage tanks.

2. The low-concentration ozone gas supply device according to claim 1, characterized in that: The ozone dilution tank also includes an ozone receiving port, and the ozone generator is connected to the ozone receiving port.

3. The low-concentration ozone gas supply device according to claim 2, characterized in that: The ozone generator is connected to an oxygen source for receiving oxygen, and a high voltage electric field is provided inside the ozone generator to convert oxygen into ozone.

4. The low-concentration ozone gas supply device according to claim 1, characterized in that: The ozone dilution tank also includes a dilution gas receiving port, and the dilution gas supplier is connected to the dilution gas receiving port.

5. The low-concentration ozone gas supply device according to claim 1, characterized in that: According to the ozone mass flow rate provided by the ozone generator, the dilution gas supplier supplies the dilution gas to the dilution space at a predetermined mass flow rate, so that the weight percentage of ozone in the low-concentration ozone gas in the dilution space is lower than 10% by weight.

6. The low-concentration ozone gas supply device according to claim 5, characterized in that: The dilution gas supplier includes a dilution gas source and a mass flow controller. The dilution gas source is used to supply the dilution gas. The mass flow controller is connected to the dilution gas source to control the mass flow of the dilution gas flowing from the dilution gas source into the dilution space.

7. The low-concentration ozone gas supply device according to claim 6, characterized in that: The dilution gas is oxygen, the dilution gas source of the dilution gas supplier is an oxygen source, and the ozone generator receives oxygen from the oxygen source.

8. The low-concentration ozone gas supply device according to claim 1, characterized in that: The ozone dilution tank is provided with an ozone pressure gauge for monitoring the pressure in the dilution space to adjust the flow of ozone and dilution gas.

9. The low-concentration ozone gas supply device according to claim 1, characterized in that: The volume of the dilution space is greater than the sum of the volumes of the gas pressure storage tank plus an addition, and the addition is greater than 10% of the sum.

10. The low-concentration ozone gas supply device according to claim 1, characterized in that: Each of the gas pressure storage tanks is connected to a corresponding reaction chamber by an ozone supply pipeline to supply the low-concentration ozone gas to the corresponding reaction chamber, and the volume of each of the gas pressure storage tanks and the length of the corresponding ozone supply pipelines are the same.

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