TWM650775U - Low concentration ozone gas supply device - Google Patents

Abstract

A low-concentration ozone gas supply device is used to provide low-concentration ozone gas to one or more reaction chambers, and includes an ozone dilution tank, an ozone generator, a dilution gas supplier and a plurality of gas pressure storage barrels. There is a dilution space inside the ozone dilution tank, 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 a 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 continues to overflow from the overflow port. The gas pressure storage barrels 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 barrels.

Description

Low concentration ozone gas supply device

The present invention relates to ozone supply in semiconductor manufacturing processes, in particular to a low-concentration ozone gas supply device.

Ozone gas is often used in CVD/ALD processes, especially for cleaning wafer surfaces to remove contaminants on the wafer surface. However, in some processes, there are sometimes important functional groups on the surface of the wafer or powder that need to be applied in subsequent processes. These functional groups are easily destroyed by reaction with ozone. At this time, a lower concentration of ozone needs to be introduced into the reaction chamber to avoid damage to the functional groups.

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

In view of the above technical problems, the present invention proposes a low-concentration ozone gas supply device to stably provide low-concentration ozone gas to one or more reaction chambers.

The present invention proposes a low-concentration ozone gas supply device for providing low-concentration ozone gas to one or more reaction chambers, including an ozone dilution tank, an ozone generator, a dilution gas supplier and a plurality of gas pressure storage barrels. . There is a dilution space inside the ozone dilution tank, 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 a 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 continues to overflow from the overflow port. The gas pressure storage barrels are connected to the dilution space; the volume of the dilution space is greater than the sum of the volumes of the gas pressure storage barrels.

In at least one embodiment, the ozone dilution tank further has an ozone receiving port, and the ozone generator is connected to the ozone receiving port.

In at least one embodiment, the ozone generator is connected to an oxygen source to receive oxygen, and a high-voltage electric field is provided inside the ozone generator to convert oxygen into ozone.

In at least one embodiment, the ozone dilution tank further has a dilution gas receiving port, and the diluting gas supplier is connected to the diluting gas receiving port.

In at least one embodiment, 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 less than 10% weight percent concentration.

In at least one embodiment, 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 flow of the dilution gas source into the dilution space. Mass flow rate of dilution gas.

In at least one embodiment, the diluting gas is oxygen, the diluting gas source of the diluting gas supplier is an oxygen source, and the ozone generator receives oxygen from the oxygen source.

In at least one embodiment, the ozone dilution tank is provided with an ozone pressure gauge for monitoring the pressure in the dilution space to adjust the flow rate of ozone and dilution gas.

In at least one embodiment, the volume of the dilution space is greater than the sum of the volumes of the gas pressure storage tanks plus an addition, and the addition is greater than 10% of the total.

In at least one embodiment, each gas pressure storage barrel 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 barrel is: The corresponding ozone supply pipelines have the same length.

Through the low-concentration ozone gas supply device proposed by the present invention, the ozone and diluent gas system are first fully mixed into low-concentration ozone gas in the ozone dilution tank, and then the gas pressure storage barrel is pressurized with the low-concentration ozone gas. The pressure accumulation through the gas pressure storage barrel can ensure that the low-concentration ozone gas injected into the reaction chamber maintains a stable concentration and flow rate, making it easier to control the process conditions (such as wafer cleaning time and temperature) in the reflection chamber. , to maintain good process effects.

100: Low concentration ozone gas supply device

110:Ozone dilution tank

112: Ozone receiving port

114: Dilution gas receiving port

116: Overflow port

120:Ozone generator

130: Dilution gas supplier

132:Mass flow controller

141,142,143: Gas pressure storage barrel

150:Ozone supply pipeline

200:Reaction chamber

CT: cold trap

D:Ozone dissociation tank

G1: Ozone pressure gauge head

G2: Vacuum pressure gauge head

G3: Cavity pressure gauge head

S1:Oxygen source

S2: Argon gas source

P1, P2: Vacuum pump

V1: Pressure relief valve

V2:Inlet valve

V3: outlet valve

V4, V5: gas valve

V6, V7: closing valve

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

Figure 2 is a schematic diagram of the pipeline design of the medium and low concentration ozone gas supply device according to the embodiment of the present invention.

Figure 3 is a schematic diagram of the pipeline design of the medium and low concentration ozone gas supply device according to the embodiment of the present invention.

Figure 4 is a schematic diagram of the pipeline design of the medium and low concentration ozone gas supply device according to the embodiment of the present invention.

Figure 5 is a schematic diagram of the pipeline design of a medium- and low-concentration ozone gas supply device according to an embodiment of the present invention.

Figure 6 is a schematic diagram of the pipeline design of the medium and low concentration ozone gas supply device according to the embodiment of the present invention.

Please refer to FIGS. 1 and 2 . A low-concentration ozone gas supply device 100 disclosed in an embodiment of the present invention includes an ozone dilution tank 110 , an ozone generator 120 , a dilution gas supplier 130 and a plurality of gases. Pressure storage barrel 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 .

As shown in Figures 1 and 2, the ozone dilution tank 110 has a dilution space inside, and the ozone dilution tank 110 has an ozone receiving port 112, a diluting gas receiving port 114 and an overflow port 116, which are respectively connected to the dilution space. .

As shown in FIGS. 1 and 2 , 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 an oxygen source S1 for receiving oxygen (O2). A high-voltage electric field is provided inside the ozone generator 120 through the electrode plate, causing oxygen molecules to dissociate into individual oxygen atoms. The individual oxygen atoms are then combined with oxygen molecules to form ozone molecules (O3).

As shown in FIGS. 1 and 2 , the dilution gas supplier 130 is connected to the dilution gas receiving port 114 for supplying a dilution gas to the dilution space. The dilution gas and ozone are mixed in the dilution space to produce low-concentration ozone gas. According to the ozone mass flow rate 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 low concentration odor in the dilution space is The ozone weight percentage concentration (wt%) in the oxygen gas can be maintained at a predetermined concentration, for example, an ozone weight percentage concentration lower than 10%, but is not limited to less than 10%.

As shown in FIGS. 1 and 2 , 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 rate of the dilution gas flowing from the dilution gas source into the dilution space.

As shown in Figures 1 and 2, the diluting gas can be oxygen (O2) or argon (Ar). When the diluting gas is oxygen (O2), the ozone generator 120 and the diluting gas supplier 130 can share the oxygen source S1, that is, the oxygen source S1 is also the diluting gas source of the diluting 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 same oxygen source S1 to use the oxygen provided by the oxygen source S1 as a dilution gas.

As shown in FIG. 3 , when the diluting gas is argon (Ar), the mass flow controller 132 is connected to the argon gas source S2 , and the argon gas source S2 is used as the diluting gas source. The argon gas source in Figure 3 can be replaced with other types of gas sources, as long as they do not easily react with ozone and do not affect the surface characteristics of the wafer. The argon gas source S2 may also be another oxygen source, that is, the ozone generator 120 and the dilution gas supplier 130 are respectively connected to different oxygen sources without sharing a single oxygen source S1.

As shown in Figures 2 and 3, specifically, the ozone generator 120 continuously supplies ozone to the dilution space of the ozone dilution tank 110, and the dilution gas supplier 130 continuously supplies dilution gas to the dilution space of the ozone dilution tank 110, and the dilution The low-concentration ozone gas in the space also continues to overflow from the overflow port 116 to the ozone dissociation tank D, so that the low-concentration ozone gas is in a continuous replenishing and overflowing state in the ozone dilution tank 110, thereby maintaining the low-concentration ozone gas. concentration and pressure. It should be noted that the ozone generator 120 does not supply pure ozone gas, but supplies a mixed gas of ozone and oxygen.

As shown in Figures 1, 2 and 3, 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 D and the gas pressure storage barrels 141, 142 to prevent gas from flowing through the overflow port. 116 and/or the gas pressure storage barrels 141, 142 backflow and contaminate low-concentration ozone gas. The overflow port 116 can also be provided with a pressure relief valve V1. The pressure relief valve V1 opens when the pressure is greater than a predetermined value and closes when the pressure is less than a predetermined value. This can also prevent external gas from flowing back into the dilution space from the overflow port 116.

As shown in Figures 1, 2 and 3, a plurality of gas pressure storage barrels 141 and 142 are respectively connected to the dilution space of the ozone dilution tank 110 through an inlet valve V2, so as to receive low-concentration ozone gas from the dilution space. The inlet valve V2 can be closed in time to prevent 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 multiple gas pressure storage barrels 141 and 142 to ensure that the ozone dilution tank 110 can supply low-concentration ozone gas with sufficient pressure to the gas pressure storage barrels 141 and 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 storage barrels 141, 142 plus the sum. The bonus can be 10%, 20% or higher of the total.

As shown in FIG. 1 , each gas pressure storage barrel 141 and 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 storage barrels 141, 142. The outlet valve V3 is used to open or close the low-concentration ozone gas supplied to the reaction chamber 200 in a timely manner. That is, by selectively opening or closing multiple 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 only to individual reaction chambers 200.

In addition, the volume of the gas pressure storage barrels 141 and 142 and the corresponding length of the ozone supply pipeline 150 will affect the concentration and flow rate of ozone. In order to make the ozone received by each reaction chamber 200 concentrated The degree is consistent with the flow rate, and the volumes of the gas pressure storage barrels 141 and 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 a 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 evacuate the remaining gas inside the gas pressure storage barrels 141, 142.

When starting to supply low-concentration ozone gas, the outlet valve V3 can be closed first, so that the low-concentration ozone gas pressure in the gas pressure storage barrels 141 and 142 is filled to the same pressure as the ozone dilution tank 110, and then the outlet valve V3 can be opened to ensure The concentration and flow rate of ozone supplied to each reaction chamber 200 can be stabilized.

As shown in FIG. 4 , the two gas pressure storage barrels 141 and 142 are only an example. In fact, there may be more than two, for example, three gas pressure storage barrels 141, 142, and 143. Each gas pressure storage barrel 141, 142, 143 is connected to a corresponding reaction chamber 200 respectively.

As shown in FIG. 1 , 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 to allow the reaction chamber 200 to receive TMA gas; the gas valve V5 can be connected to a nitrogen gas source to allow the reaction chamber 200 to receive nitrogen gas. 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 change after the operation of the vacuum pump P2. 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 can also be connected to a chamber pressure gauge G3 through the closing valve V7 to monitor the pressure inside the reaction chamber 200 .

As shown in FIG. 5 , when the ozone generation amount of the ozone generator 120 is insufficient, the low-concentration ozone gas supply device 100 may include multiple ozone generators 120 , which are respectively connected to the ozone dilution tank 110 , or connected in parallel to the ozone dilution tank. 110 to ensure adequate ozone supply.

As shown in FIG. 5 , when the ozone generation amount of the ozone generator 120 is insufficient, the low-concentration ozone gas supply device 100 may include multiple ozone generators 120 , which are respectively connected to the ozone dilution tank 110 , or connected in parallel to the ozone dilution tank. 110 to ensure adequate ozone supply.

As shown in Figure 6, 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 multiple gas pressure storage barrels 141, 142, or the volume of the dilution space is smaller than the volume of multiple gas pressure storage barrels. When the sum of the volumes 141 and 142 is added, the low-concentration ozone gas supply device 100 may include a plurality of ozone dilution tanks 110 . The plurality of ozone dilution tanks 110 are interconnected to balance the pressure of ozone gas and the concentration of ozone. Multiple ozone dilution tanks 110 can be configured 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. Multiple ozone dilution tanks 110 can be configured in parallel. Ozone and dilution gas are injected into multiple ozone dilution tanks 110 at the same time. The low-concentration ozone gas output by multiple ozone dilution tanks 110 is combined through the manifold and then divided into each gas pressure storage tank. 141,142.

Through the low-concentration ozone gas supply device 100 proposed in the present invention, the ozone and diluent gas system are first fully mixed into low-concentration ozone gas in the ozone dilution tank 110, and then the gas pressure storage barrels 141 and 142 are pressurized with the low-concentration ozone gas. The pressure accumulation through 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 as to make it easier to reflect the process conditions in the chamber (such as wafer cleaning time and temperature) Control and maintain good process results.

100: Low concentration ozone gas supply device

110:Ozone dilution tank

112: Ozone receiving port

114: Dilution gas receiving port

116: Overflow port

120:Ozone generator

130: Dilution gas supplier

141,142: Gas pressure storage barrel

150:Ozone supply pipeline

200:Reaction chamber

CT: cold trap

D:Ozone dissociation tank

G1: Ozone pressure gauge head

G2: Vacuum pressure gauge head

G3: Cavity pressure gauge head

S1:Oxygen source

P1, P2: Vacuum pump

V1: Pressure relief valve

V2:Inlet valve

V3: outlet valve

V4, V5: gas valve

V6, V7: closing valve

Claims (10)

A low-concentration ozone gas supply device used to provide low-concentration ozone gas to one or more reaction chambers, including: an ozone dilution tank with a dilution space inside, and the ozone dilution tank has an overflow port connected to the dilution space; an ozone generator for continuously supplying ozone to the dilution space of the ozone dilution tank; a dilution gas supplier for supplying a dilution gas to the dilution space so that the ozone and the dilution gas are in The dilution space is mixed to form the low-concentration ozone gas, and the low-concentration ozone gas in the dilution space continues to overflow from the overflow port; and a plurality of gas pressure storage barrels are connected to the dilution space to receive the low-concentration ozone respectively. Gas; wherein the volume of the dilution space is greater than the sum of the volumes of the gas pressure storage barrels. The low-concentration ozone gas supply device of claim 1, wherein the ozone dilution tank further has an ozone receiving port, and the ozone generator is connected to the ozone receiving port. The low-concentration ozone gas supply device of claim 2, wherein the ozone generator is connected to an oxygen source to receive oxygen, and a high-voltage electric field is provided inside the ozone generator to convert oxygen into ozone. The low-concentration ozone gas supply device as claimed in claim 1, wherein the ozone dilution tank further has a dilution gas receiving port, and the diluting gas supplier is connected to the diluting gas receiving port. The low-concentration ozone gas supply device as claimed in claim 1, wherein the dilution gas supplier supplies dilution gas at a predetermined mass flow rate based on the ozone mass flow rate provided by the ozone generator. The gas is transferred to the dilution space so that the weight percentage of ozone in the low-concentration ozone gas in the dilution space is lower than the weight percentage concentration of 10%. The low-concentration ozone gas supply device as claimed in claim 5, wherein 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, and the mass flow controller is connected to The dilution gas source is used to control the mass flow rate of the dilution gas flowing into the dilution space from the dilution gas source. The low-concentration ozone gas supply device of claim 6, wherein the diluting gas is oxygen, the diluting gas source of the diluting gas supplier is an oxygen source, and the ozone generator receives oxygen from the oxygen source. The low-concentration ozone gas supply device as claimed in claim 1, wherein the ozone dilution tank is provided with an ozone pressure gauge for monitoring the pressure in the dilution space to adjust the flow rate of ozone and dilution gas. The low-concentration ozone gas supply device as claimed in claim 1, wherein the volume of the dilution space is greater than the sum of the volumes of the gas pressure storage tanks plus an addition, and the addition is greater than 10% of the total. The low-concentration ozone gas supply device as claimed in claim 1, wherein each gas pressure storage barrel is connected to a corresponding reaction chamber by an ozone supply pipeline to supply the low-concentration ozone gas to the corresponding reaction chamber. The reaction chamber, the volume of each gas pressure storage barrel and the length of the corresponding ozone supply pipeline are the same.

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