Water vapor generating device, liquid level control method and semiconductor process chamber

Abstract

The invention discloses a water vapor generating device, a liquid level control method and a semiconductor process chamber. The device comprises a water tank, the bottom of the water tank is connected with a water supplementing pipeline, the top of the water tank is communicated with the process chamber through a steam conveying pipeline, a water supplementing valve is arranged on the water supplementing pipeline, and a gas flow control piece is arranged on the steam conveying pipeline; the water tank is provided with a heating piece, a temperature detection piece, a pressure detection piece and a liquid level detection piece; the controller is respectively connected with the water replenishing valve, the heating piece, the temperature detection piece, the pressure detection piece and the liquid level detection piece; and the controller is used for controlling the opening or closing of the water replenishing valve to carry out circulating water replenishing according to the pressure and temperature of the water vapor and the set temperature and pressure conditions when the liquid level of the deionized water in the water tank is lower than the set water replenishing liquid level, so that the pressure and temperature of the water vapor in the water tank always meet the process requirements in the water replenishing process. According to the invention, the water vapor required by the process can be continuously and stably supplied to the process chamber in the water replenishing process.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor equipment, and more specifically, relates to a water vapor generating device, a liquid level control method and a semiconductor process chamber. Background Art

[0002] In the application environment of semiconductor equipment, after the metal etching process, the vacuum transfer platform will transfer the etched wafer to the degumming process chamber for degumming and passivation processes. The degumming process chamber usually uses three gases, including oxygen, nitrogen, and water vapor. The degumming process consists of three steps: wafer heating, passivation, and degumming. In the passivation step, a certain amount of water vapor will be introduced into the chamber. In a microwave environment, the water vapor will be ionized to generate hydrogen ions and oxygen ions. The oxygen ions react with the aluminum on the surface of the wafer to form a dense aluminum oxide layer to protect the aluminum surface. The hydrogen ions react with the residual chloride generated by the metal etching process on the wafer surface to generate hydrogen chloride gas, which is pumped out of the chamber through a dry pump to achieve dechlorination. During the passivation process, the stability and continuity of the water vapor supply directly affects the process yield of the degumming process chamber. The water vapor used in the degumming process chamber is usually provided by a water vapor generator by heating liquid deionized water to vaporize it. During the process of the degumming process chamber, as the water vapor is consumed, the water vapor generator needs to continuously replenish deionized water. The water replenishment control method is one of the key technologies for controlling the water vapor supply in the degumming process chamber.

[0003] The water vapor generating device of the existing degumming process chamber has the problem of unstable water vapor supply during the replenishment process. Summary of the invention

[0004] The purpose of the present invention is to provide a water vapor generating device, a liquid level control method and a semiconductor process chamber, so as to realize an uninterrupted and stable supply of water vapor required for the process to the process chamber during the water replenishment process.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a water vapor generating device for use in a semiconductor process chamber, the device comprising:

[0006] A water tank for storing deionized water and water vapor, wherein the bottom of the water tank is connected to a water supply pipeline, and the top of the water tank is connected to the process chamber through a steam delivery pipeline, wherein a water supply valve is provided on the water supply pipeline, and a gas flow control element is provided on the steam delivery pipeline;

[0007] The water tank is provided with a heating element, a temperature detecting element, a pressure detecting element and a liquid level detecting element, wherein the heating element is used to heat the water tank to generate saturated water vapor, the temperature detecting element is used to detect the temperature of the water vapor in the water tank, the pressure detecting element is used to detect the pressure of the water vapor in the water tank, and the liquid level detecting element is used to detect the liquid level of deionized water in the water tank;

[0008] A controller, wherein the controller is respectively connected to the water supply valve, the heating element, the temperature detection element, the pressure detection element and the liquid level detection element;

[0009] The controller is used to: when the liquid level of deionized water in the water tank is lower than the set water replenishment level, control the water replenishment valve to open or close for circulating water replenishment according to the pressure and temperature of the water vapor and the set temperature and pressure conditions, so that the pressure and temperature of the water vapor in the water tank always meet the process requirements during the water replenishment process.

[0010] Optionally, the water replenishment valve comprises a high-frequency solenoid valve.

[0011] Optionally, the controller includes a control chip and a liquid level acquisition module, a pressure acquisition module, a temperature acquisition module and a digital signal output module respectively connected to the control chip;

[0012] The liquid level acquisition module is connected to the liquid level detection element and is used to read the liquid level signal measured by the liquid level detection element;

[0013] The pressure acquisition module is connected to the pressure detection element and is used to read the pressure signal measured by the pressure detection element;

[0014] The temperature acquisition module is connected to the temperature detection element and is used to read the temperature signal measured by the temperature detection element;

[0015] The control chip is used to execute a water replenishment control process according to the liquid level signal, the pressure signal and the temperature signal;

[0016] The digital signal output module is connected to the water supply valve and is used to send a control signal to the water supply valve.

[0017] Optionally, a normally open water inlet pneumatic valve is further provided on the water replenishment pipeline, the water inlet pneumatic valve is arranged in the upstream pipeline of the water replenishment valve, and the water inlet pneumatic valve is connected to the digital signal output module.

[0018] Optionally, the gas flow control element comprises a mass flow controller;

[0019] The steam delivery pipeline is also provided with a chamber air intake valve, and the chamber air intake valve is arranged in the downstream pipeline of the gas flow control component.

[0020] Optionally, a drainage pipeline is provided at the bottom of the box body, and a drainage valve is provided on the drainage pipeline.

[0021] Optionally, a purge gas pipeline is further included, the purge gas pipeline is connected to the water supply pipeline, and the purge gas pipeline is used to pass purge gas into the water tank;

[0022] The purge gas pipeline is provided with an air intake pneumatic valve and a one-way valve in sequence along the upstream to downstream direction of the air flow.

[0023] In a second aspect, the present invention provides a liquid level control method for the water vapor generating device according to the first aspect, comprising:

[0024] Real-time monitoring of whether the liquid level of deionized water in the water tank is lower than the set water replenishment level, if so, executing the water replenishment process, the water replenishment process includes:

[0025] When the temperature of the water vapor in the water tank is greater than the first set temperature and the pressure of the water vapor is greater than the first set pressure, the water replenishment valve is controlled to open to replenish water;

[0026] When the temperature of the water vapor in the water tank is less than or equal to the first set temperature or the pressure of the water vapor is less than or equal to the first set pressure, the water replenishment valve is controlled to be closed until the temperature of the water vapor is heated to a temperature greater than or equal to the second set temperature and the pressure of the water vapor is greater than or equal to the second set pressure. The water replenishment valve is controlled to be opened and the steps of determining whether the temperature of the water vapor is greater than the first set temperature and whether the pressure of the water vapor is greater than the first set pressure are re-executed until the liquid level of the deionized water in the water tank reaches the set target liquid level, and the water replenishment process is stopped.

[0027] Optionally, the first set pressure is greater than the minimum pressure required for water vapor in the water tank;

[0028] The first set temperature is the temperature corresponding to when the water vapor in the water tank reaches the first set pressure;

[0029] The second set temperature is a set target temperature for controlling the temperature of the water tank;

[0030] The second set pressure is the pressure corresponding to when the water vapor in the water tank reaches the second set temperature.

[0031] Optionally, the minimum pressure required for the water vapor in the water tank is in the range of 400 Tor to 450 Tor;

[0032] The first set pressure ranges from 450 Tor to 526 Tor;

[0033] The second set pressure ranges from 526 Tor to 600 Tor.

[0034] Optionally, it also includes:

[0035] When the pressure of the water vapor in the water tank is lower than the minimum pressure required for the water vapor in the water tank, an alarm is issued.

[0036] Optionally, the method further includes: providing an alarm when the liquid level of the deionized water in the water tank is lower than a set minimum liquid level or higher than a set maximum liquid level.

[0037] In a third aspect, the present invention provides a semiconductor device, comprising a semiconductor process chamber and the water vapor generating device described in the first aspect.

[0038] The beneficial effects of the present invention are:

[0039] The present invention monitors the state of steam in the water tank by adding a pressure detection component and a temperature detection component to the water tank. During the water replenishment process, the controller controls the opening or closing of the water replenishment valve based on the pressure and temperature of the water vapor and the set temperature and pressure conditions to perform intermittent cyclic water replenishment. During the period when the water replenishment valve is closed, the water vapor temperature and pressure in the water tank can be heated to reach the desired state, so that the pressure and temperature of the water vapor in the water tank can always meet the process requirements during the water replenishment process, thereby achieving an uninterrupted and stable supply of water vapor required for the process to the process chamber while the water tank is replenished.

[0040] The system of the present invention has other characteristics and advantages, which will be apparent from the drawings incorporated herein and the following detailed description, or will be described in detail in the drawings incorporated herein and the following detailed description, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which like reference numerals generally represent like components.

[0042] Figure 1 A schematic diagram of a water vapor generating device according to prior art 1 is shown.

[0043] Figure 2 A schematic diagram of a water vapor generating device of prior art II is shown.

[0044] Figure 3 A schematic diagram of a water vapor generating device according to Example 1 of the present invention is shown.

[0045] Figure 4 A control flow chart of a liquid level control method for a water vapor generating device according to Embodiment 2 of the present invention is shown.

[0046] Figure 5 A saturated water vapor temperature-pressure curve diagram in a liquid level control method for a water vapor generating device according to Example 2 of the present invention is shown.

[0047] Figure 6 A timing diagram of water vapor pressure, liquid level, and water inlet high-frequency electromagnetic valve switching in a liquid level control method for a water vapor generating device according to Example 2 of the present invention is shown. DETAILED DESCRIPTION

[0048] A water vapor generating device for a degumming process chamber disclosed in the prior art Figure 1 As shown in the figure, the liquid level gauge is a sensor for judging the liquid level in the water tank. The scales of the liquid level gauge are L (Low), M (Middle), H (High), and HH (High High) from low to high. When the liquid level is lower than L or higher than HH, the water vapor generating device alarms. The normal working water level is between L and HH. During process use, when the liquid level is lower than M, the water inlet pneumatic valve and the water inlet solenoid valve automatically open to inject deionized water. When the liquid level reaches H, water replenishment stops.

[0049] This solution has the following disadvantages:

[0050] The deionized water provided by factory services in the semiconductor industry is liquid water at room temperature of 25°C. After entering the water tank, the temperature of the water and the tank drops rapidly, which can easily cause condensation of water vapor in the water tank. Condensation causes the water vapor pressure to drop, and the flow control of the mass flow controller is unstable, which in turn leads to unstable water vapor supply entering the degumming process chamber, resulting in a decrease in process yield.

[0051] A water vapor generating device for a degumming process chamber disclosed in the prior art 2 is as follows Figure 2 As shown, on the basis of the prior art one, an air box is added to the box structure. The water tank is mainly used to store deionized water and heat the deionized water to vaporize it, and the air box is used to store the water vapor generated by the water tank. An isolation solenoid valve is added between the two boxes to isolate and control the on and off of the two boxes. When the air is flowing, the isolation solenoid valve is opened to allow water vapor to enter the air box. After the air box pressure reaches the set value, the isolation solenoid valve is closed. When the air box pressure drops to the minimum allowable pressure, the isolation solenoid valve is opened again to replenish water vapor to the air box. When replenishing water, the isolation solenoid valve is closed to isolate the air box from the water tank to avoid the rapid decrease in the water vapor concentration and pressure in the air box during water replenishment. The water replenishment control method of the prior art two is the same as the prior art one, which is to start replenishing water when the liquid level is lower than M and stop when the liquid level reaches H.

[0052] The second prior art has the following disadvantages:

[0053] 1. The added gas box significantly increases the volume of the water vapor generator. The volume of the degumming process chamber is smaller than that of other plasma equipment, and it is mostly mounted on the Load Lock station of the transfer chamber. The space is small, and the increase in volume is prone to assembly risks.

[0054] 2. One of the key technical indicators of the degumming process chamber is metal contamination. In order to avoid metal contamination, the water vapor generator box of the degumming process chamber is made of pure titanium or titanium alloy. The cost of adding a box in the existing technology is extremely expensive.

[0055] 3. When the pressure in the gas tank is lower than the set value for allowing gas flow and water vapor needs to be supplemented, when the water tank liquid level is critically close to M, if the deionized water in the water tank is vaporized during the heating process and the liquid level drops to M, water replenishment is triggered, water vapor condenses in the water tank and the pressure drops. At the same time, the isolation solenoid valve cannot be opened at the same time as the water inlet solenoid valve, and the water vapor supply will be interrupted due to the inability to replenish gas.

[0056] The present invention provides a water vapor generating device, a liquid level control method and a semiconductor process chamber, which can realize water replenishment without increasing the volume and on the basis of controllable cost, and at the same time supply water vapor to the degumming process chamber uninterruptedly and stably.

[0057] The present invention will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0058] Example 1

[0059] like Figure 3 As shown, this embodiment provides a water vapor generating device, which is applied to a semiconductor process chamber, and the device includes:

[0060] A water tank 1 is used to store deionized water and water vapor. The bottom of the water tank 1 is connected to a water supply pipeline. The top of the water tank 1 is connected to a process chamber 3 through a steam delivery pipeline. A water supply valve 9 is provided on the water supply pipeline. A gas flow control element 8 is provided on the steam delivery pipeline.

[0061] The water tank 1 is provided with a heating element 4, a temperature detection element 5, a pressure detection element 6 and a liquid level detection element 7. The heating element 4 is used to heat the water tank 1 to generate saturated water vapor, the temperature detection element 5 is used to detect the temperature of the water vapor in the water tank 1, the pressure detection element 6 is used to detect the pressure of the water vapor in the water tank 1, and the liquid level detection element 7 is used to detect the liquid level of deionized water in the water tank 1;

[0062] The controller 2 is connected to the water supply valve 9, the heating element 4, the temperature detection element 5, the pressure detection element 6 and the liquid level detection element 7 respectively;

[0063] The controller 2 is used to: when the liquid level of deionized water in the water tank 1 is lower than the set water replenishment level, control the water replenishment valve 9 to open or close for circulating water replenishment according to the pressure and temperature of the water vapor and the set temperature and pressure conditions, so that the pressure and temperature of the water vapor in the water tank 1 always meet the process requirements during the water replenishment process.

[0064] Preferably, the water replenishment valve 9 in this embodiment is a high-frequency solenoid valve.

[0065] In this embodiment, the process chamber is a degumming process chamber 3, the heating element 4 is a resistance heating belt, the temperature detection element 5 is a thermocouple, the pressure detection element 6 is a pressure gauge, the liquid level detection element 7 is a liquid level gauge, and the gas flow control element 8 is a mass flow controller 2.

[0066] In this embodiment, a normally open water inlet pneumatic valve 11 is also provided on the water supply pipeline. The water inlet pneumatic valve 11 is arranged in the upstream pipeline of the water supply valve 9 , and the water inlet pneumatic valve 11 is connected to the digital signal output module 205 .

[0067] Specifically, deionized water enters the water tank 1 through the water inlet pneumatic valve 11 and the high-frequency solenoid valve. The water inlet pneumatic valve 11 is normally open when the water vapor generator is in working state, and the water inlet high-frequency solenoid valve is switched on and off based on the data collection of the liquid level meter, the pressure gauge and the thermocouple. Compared with the prior art 1, the solenoid valve on the water supply pipeline is replaced with a high-frequency solenoid valve, and the high-frequency solenoid valve is used to improve the response speed of the water supply valve 9 on and off, and millisecond-level switching can be achieved.

[0068] In this embodiment, the controller 2 includes a control chip 201 and a liquid level acquisition module 202, a pressure acquisition module 203, a temperature acquisition module 204 and a digital signal output module 205 respectively connected to the control chip 201;

[0069] The liquid level acquisition module 202 is connected to the liquid level detection component 7, and is used to read the liquid level signal measured by the liquid level detection component 7; the pressure acquisition module 203 is connected to the pressure detection component 6, and is used to read the pressure signal measured by the pressure detection component 6; the temperature acquisition module 204 is connected to the temperature detection component 5, and is used to read the temperature signal measured by the temperature detection component 5; the control chip 201 is used to execute the water replenishment control process according to the liquid level signal, pressure signal and temperature signal; the digital signal output module 205 is connected to the water replenishment valve 9, and is used to send a control signal to the water replenishment valve 9.

[0070] In this embodiment, the liquid level acquisition module 202, the pressure acquisition module 203 and the temperature acquisition module 204 are all analog acquisition modules, and the control chip 201 can be a single-chip microcomputer chip. In other embodiments, the controller 2 can also be a PLC controller 2. In this embodiment, the controller 2 also includes a power supply module 206.

[0071] Specifically, the liquid level meter indicates the liquid level in the water tank 1 through voltage output, and reads the real-time liquid level value through the liquid level acquisition module 202 in the controller 2. The pressure gauge indicates the water vapor pressure in the water tank 1 through voltage output, and reads the real-time pressure through the pressure acquisition module 203 in the liquid level control board. The thermocouple reads the temperature in the water tank 1 through the temperature acquisition module 204. After the three types of information are collected into the control chip 201, the control chip 201 performs logical judgment control and drives the high-frequency solenoid valve switch through the digital signal output module 205.

[0072] In this embodiment, a chamber air inlet valve 10 is further provided on the steam delivery pipeline, and the chamber air inlet valve 10 is arranged in the downstream pipeline of the gas flow control element 8. The chamber air inlet valve 10 is kept open when the process chamber 3 is working, and is closed when the process stops.

[0073] In this embodiment, a drainage pipeline is provided at the bottom of the box body, and a drainage valve 14 is provided on the drainage pipeline.

[0074] The device also includes a purge gas pipeline, which is connected to the water supply pipeline, and the purge gas pipeline is used to pass the purge gas into the water tank 1;

[0075] An air inlet pneumatic valve 12 and a one-way valve 13 are provided in sequence along the upstream to downstream direction of the air flow on the purge gas pipeline.

[0076] The drain valve 14 is a solenoid valve, and the purge gas is pure nitrogen.

[0077] Specifically, when the water tank 1 and the pipeline need to be cleaned, the deionized water in the water tank 1 can be discharged first by opening the drain, and then nitrogen is introduced into the tank body by opening the air inlet pneumatic valve 12 on the purge gas pipeline to purge the water tank 1.

[0078] Example 2

[0079] like Figure 4 As shown, this embodiment provides a liquid level control method for the water vapor generating device of embodiment 1, comprising:

[0080] Real-time monitoring of whether the liquid level of deionized water in the water tank 1 is lower than the set water replenishment level. If so, the water replenishment process is executed. The water replenishment process includes:

[0081] When the temperature of the water vapor in the water tank 1 is greater than the first set temperature and the pressure of the water vapor is greater than the first set pressure, the water replenishment valve 9 is controlled to open to replenish water;

[0082] When the temperature of the water vapor in the water tank 1 is less than or equal to the first set temperature or the pressure of the water vapor is less than or equal to the first set pressure, the water replenishment valve 9 is controlled to be closed until the temperature of the water vapor is heated to a temperature greater than or equal to the second set temperature and the pressure of the water vapor is greater than or equal to the second set pressure. The water replenishment valve 9 is controlled to be opened and the steps of determining whether the temperature of the water vapor is greater than the first set temperature and whether the pressure of the water vapor is greater than the first set pressure are re-executed until the liquid level of the deionized water in the water tank 1 reaches the set target liquid level, and the water replenishment process is stopped.

[0083] Wherein, the first set pressure is greater than the minimum pressure required for water vapor in the water tank 1;

[0084] The first set temperature is the temperature corresponding to when the water vapor in the water tank 1 reaches the first set pressure;

[0085] The second set temperature is a set target temperature for controlling the temperature of the water tank 1;

[0086] The second set pressure is the pressure corresponding to when the water vapor in the water tank 1 reaches the second set temperature.

[0087] The range of the first set pressure and the second set pressure needs to be set according to the front-end and rear-end pressure difference range of the normal operation of the mass flow controller 2 and the required water vapor flow rate, water vapor pressure and other conditions in the process chamber.

[0088] Specifically, Figure 3 As shown, the liquid level in the water tank 1 is divided into five areas, less than L, L~M, M~H, H~HH, and greater than HH. Under normal supply of water vapor, the liquid level of deionized water in the water tank 1 operates between L and HH. When the liquid level is lower than M, it is set to enter the water replenishment process.

[0089] In the water replenishment process, the pressure judgment of water vapor is based on the front-end and rear-end pressure difference range that can meet the normal operation of the mass flow controller 2, and the gas pressure in the front-end water tank 1 needs to be greater than the chamber pressure of the rear-end degumming process chamber 3. Among them, the front-end and rear-end working pressure difference range of the high-temperature gas mass flow controller 2 is approximately 375~2625Tor, and the chamber pressure of the degumming process chamber 3 is 1~9Tor.

[0090] The ideal gas state equation in a certain volume of space is: pV = nRT, where p is pressure, V is volume, n is the amount of substance, R is the universal gas constant, and T is the absolute temperature;

[0091] When the volume and temperature of the water tank 1 of the water vapor generating device are constant, according to the above ideal gas state equation, it can be known that the amount of water vapor in the water tank 1 is proportional to the pressure, and the water vapor flow rate required by the degumming process chamber 3 is 1-3L / min, and the process time is 10-20min. Therefore, in the state where the water vapor flow rate required by the process can be output, the minimum pressure value required for the water vapor in the water tank 1 is p1 (400-450Tor). Combining the pressure difference requirements of the mass flow meter (375Tor-2625Tor), the pressure difference requirements between the water tank 1 and the chamber (>1-9Tor), and the process flow pressure requirements (>400-450Tor), it can be known that when it is lower than p1 (400-450Tor), the water vapor generating device will not be able to output the amount of water vapor that meets the process requirements. Therefore, the minimum pressure value p1 required for the water vapor in the water tank 1 is the lower limit of the pressure value of the water vapor output by the water tank 1. In this embodiment, the minimum pressure required for the water vapor in the water tank 1 is in the range of 400 Tor to 450 Tor.

[0092] like Figure 5 As shown, when the water vapor pressure in the water tank 1 is p1, the temperature in the water tank 1 can be obtained as T1 according to the saturated water vapor curve. The water vapor generating device adopts temperature control heating, and the set target temperature of heating is T0. According to the saturated water vapor curve, the corresponding target pressure of saturated water vapor can be obtained as p0. When T0 is 90-95°C, the target pressure p0 of saturated water vapor is about 526-600Tor, that is, the range of the second set pressure is 526Tor-600Tor.

[0093] When the liquid level is at M, the mass of water with the original temperature T0 in water tank 1 is m0. According to the specific heat capacity formula: Q=cm(ΔT) (where Q is heat, c is specific heat capacity, m is mass, and ΔT is temperature change), when the water supply valve 9 is opened, the mass of 25°C deionized water entering water tank 1 per second is m1 (0.26~0.56g / s). At this time, the heat released by the original water in water tank 1 is Q0=cm0(T0-ΔT), and the heat absorbed by the new water entering water tank 1 is Q1=cm1(ΔT1-25°C), Q1=Q0. Under the ideal state of not considering heating within one second, the temperature of the replenished water drops by ΔT(℃ / s)=(m0T0+25m1) / (m0+m1) per second at the water level M and temperature T0, which is about 0.11~0.24℃ / s at the heating temperature of 90℃. The temperature in water tank 1 will drop with the replenishment of water. According to the saturated water vapor curve, the saturated water vapor pressure decreases synchronously with the decrease in temperature.

[0094] Based on the above principle of pressure and temperature drop during water replenishment, Figure 5As shown, in this embodiment, p2 is preferably selected between p0 and p1 as the first set pressure in the water replenishment control process, and the preferred range of the first set pressure p2 is 450Tor~526Tor. In the saturated water vapor temperature-pressure curve, the temperature value corresponding to the first set pressure p2 is T2, which is used as the first set temperature. At the same time, the temperature control target temperature T0 is selected as the upper limit of the temperature for heating the water vapor in the water replenishment process, and the steam target pressure p0 corresponding to the temperature control target temperature T0 is the upper limit of the pressure for heating the water vapor in the water replenishment process.

[0095] Based on the above principles, reference Figure 4 The water replenishment control logic of the water level control method of this embodiment is: when the liquid level is lower than M, the water replenishment process is entered. At this time, the controller 2 enters the pressure and temperature judgment. When the pressure is greater than the first set pressure p2 and the temperature is greater than the first set temperature T2, the water inlet high-frequency solenoid valve is controlled to open for water replenishment. When the pressure is less than the first set pressure p2 or the temperature is lower than the first setting T2, the water inlet high-frequency solenoid valve is controlled to close, and the water tank 1 is heated until the water vapor pressure reaches the second set pressure p0 and the temperature reaches the second setting T0, and the water inlet high-frequency solenoid valve is opened to replenish water. The above process is repeated until the water level reaches H, and the water replenishment process ends.

[0096] The timing diagram of liquid level control during water replenishment is as follows: Figure 6 As shown, the temperature and pressure of the water vapor in the tank fluctuate along the curve between (T2, p2) and (T0, p0). The water vapor pressure is always kept at a position higher than the minimum allowable pressure p1, which can ensure the continuous and stable supply of water vapor, and the liquid level is gradually replenished from the M water level to the H water level. The smaller the difference between p2 and p0, the smaller the fluctuation of the water vapor pressure in the water tank 1, the more stable the gas flow, and the higher the switching frequency of the water inlet high-frequency solenoid valve. When the difference between p2 and p0 approaches 0, the water vapor pressure in the water tank 1 approaches a constant. On the basis of not affecting the stability of the gas flow, considering the water replenishment time and the life of the solenoid valve switching times, it is preferred that p2 should be selected between 480 and 500 Tor. According to the temperature drop rate per second during water replenishment and the corresponding pressure drop rate, it can be estimated that the water replenishment process from M to H (liquid level 170ml to 210ml, a total of 40ml water replenishment) will be divided into 6 to 25 times.

[0097] Preferably, the method of this embodiment further includes:

[0098] When the pressure of the water vapor in the water tank 1 is lower than the minimum pressure required for the water vapor in the water tank 1, an alarm is triggered.

[0099] When the liquid level of the deionized water in the water tank 1 is lower than the set minimum liquid level or higher than the set maximum liquid level, an alarm is triggered.

[0100] Specifically, p1 is used as the lower limit of the pressure monitoring in the water tank 1. When the pressure in the water tank 1 is lower than p1, the water vapor generating device issues a low pressure alarm. At this time, the degumming process chamber 3 cannot start the process until the pressure is greater than p1 and the alarm is eliminated. When the liquid level is lower than L or higher than HH, the system liquid level alarm is issued. If the liquid level is lower than L, the degumming process chamber 3 process needs to be stopped and the water replenishment process needs to be executed; if the liquid level is higher than HH, the drain valve 14 can be opened to drain water and adjust the liquid level to between M and H.

[0101] Example 3

[0102] This embodiment provides a semiconductor device, including a semiconductor process chamber and the water vapor generating device of embodiment 1.

[0103] In one example, reference Figure 3 The semiconductor process chamber can be a degumming process chamber 3, which is also connected to a process gas delivery pipeline. A process gas inlet valve is provided on the process gas delivery pipeline. The process gas delivery pipeline is used to introduce oxygen and nitrogen required for the degumming process into the degumming process chamber 3.

[0104] The water vapor generating device of Example 1 is used and the water level control method of Example 2 is applied during the process to execute the water replenishment process for the water vapor generating device. During the water replenishment process, the water vapor required for the process can be continuously and stably supplied to the degumming process chamber 3, effectively ensuring the supply of water vapor required for the degumming process and improving the quality of the degumming process.

[0105] It should be noted that the above-mentioned semiconductor process chamber is not limited to a degumming process chamber, but can also be other semiconductor process chambers that require a stable supply of water vapor. The same technical effect can also be achieved by using the water vapor generating device of the present invention.

[0106] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A water vapor generating device, used in a semiconductor process chamber, characterized in that: The device comprises: A water tank for storing deionized water and water vapor, wherein the bottom of the water tank is connected to a water supply pipeline, and the top of the water tank is connected to the process chamber through a steam delivery pipeline, wherein a water supply valve is provided on the water supply pipeline, and a gas flow control element is provided on the steam delivery pipeline; The water tank is provided with a heating element, a temperature detecting element, a pressure detecting element and a liquid level detecting element, wherein the heating element is used to heat the water tank to generate saturated water vapor, the temperature detecting element is used to detect the temperature of the water vapor in the water tank, the pressure detecting element is used to detect the pressure of the water vapor in the water tank, and the liquid level detecting element is used to detect the liquid level of deionized water in the water tank; A controller, wherein the controller is respectively connected to the water supply valve, the heating element, the temperature detection element, the pressure detection element and the liquid level detection element; The controller is used to: when the liquid level of deionized water in the water tank is lower than the set water replenishment level, control the water replenishment valve to open or close for circulating water replenishment according to the pressure and temperature of the water vapor and the set temperature and pressure conditions, so that the pressure and temperature of the water vapor in the water tank always meet the process requirements during the water replenishment process.

2. The water vapor generating device according to claim 1, characterized in that: The water supply valve comprises a high-frequency solenoid valve.

3. The water vapor generating device according to claim 1, characterized in that: The controller includes a control chip and a liquid level acquisition module, a pressure acquisition module, a temperature acquisition module and a digital signal output module respectively connected to the control chip; The liquid level acquisition module is connected to the liquid level detection element and is used to read the liquid level signal measured by the liquid level detection element; The pressure acquisition module is connected to the pressure detection element and is used to read the pressure signal measured by the pressure detection element; The temperature acquisition module is connected to the temperature detection element and is used to read the temperature signal measured by the temperature detection element; The control chip is used to execute a water replenishment control process according to the liquid level signal, the pressure signal and the temperature signal; The digital signal output module is connected to the water supply valve and is used to send a control signal to the water supply valve.

4. The water vapor generating device according to claim 3, characterized in that: The water replenishment pipeline is also provided with a normally open water inlet pneumatic valve, the water inlet pneumatic valve is arranged in the upstream pipeline of the water replenishment valve, and the water inlet pneumatic valve is connected to the digital signal output module.

5. The water vapor generating device according to claim 1, characterized in that: The gas flow control element includes a mass flow controller; The steam delivery pipeline is also provided with a chamber air intake valve, and the chamber air intake valve is arranged in the downstream pipeline of the gas flow control component.

6. The water vapor generating device according to claim 1, characterized in that: A drainage pipeline is provided at the bottom of the box body, and a drainage valve is provided on the drainage pipeline.

7. The water vapor generating device according to claim 1, characterized in that: It also includes a purge gas pipeline, the purge gas pipeline is connected to the water supply pipeline, and the purge gas pipeline is used to pass purge gas into the water tank; The purge gas pipeline is provided with an air intake pneumatic valve and a one-way valve in sequence along the upstream to downstream direction of the air flow.

8. A liquid level control method for a water vapor generating device according to any one of claims 1 to 7, characterized in that: include: Real-time monitoring of whether the liquid level of deionized water in the water tank is lower than the set water replenishment level, if so, executing the water replenishment process, the water replenishment process includes: When the temperature of the water vapor in the water tank is greater than the first set temperature and the pressure of the water vapor is greater than the first set pressure, the water replenishment valve is controlled to open to replenish water; When the temperature of the water vapor in the water tank is less than or equal to the first set temperature or the pressure of the water vapor is less than or equal to the first set pressure, the water replenishment valve is controlled to be closed until the temperature of the water vapor is heated to a temperature greater than or equal to the second set temperature and the pressure of the water vapor is greater than or equal to the second set pressure. The water replenishment valve is controlled to be opened and the step of determining whether the temperature of the water vapor is greater than the first set temperature and whether the pressure of the water vapor is greater than the first set pressure is re-executed until the liquid level of the deionized water in the water tank reaches the set target liquid level, and the water replenishment process is stopped.

9. The liquid level control method according to claim 8, characterized in that: The first set pressure is greater than the minimum pressure required for water vapor in the water tank; The first set temperature is the temperature corresponding to when the water vapor in the water tank reaches the first set pressure; The second set temperature is a set target temperature for controlling the temperature of the water tank; The second set pressure is the pressure corresponding to when the water vapor in the water tank reaches the second set temperature.

10. The liquid level control method according to claim 9, characterized in that: The minimum pressure required for the water vapor in the water tank is in the range of 400Tor to 450Tor; The first set pressure ranges from 450 Tor to 526 Tor; The second set pressure ranges from 526 Tor to 600 Tor.

11. The liquid level control method according to claim 9, characterized in that: Also includes: When the pressure of the water vapor in the water tank is lower than the minimum pressure required for the water vapor in the water tank, an alarm is issued.

12. The liquid level control method according to claim 8, characterized in that: Also includes: When the liquid level of the deionized water in the water tank is lower than a set minimum liquid level or higher than a set maximum liquid level, an alarm is triggered.

13. A semiconductor device, characterized in that: The invention comprises a semiconductor process chamber and a water vapor generating device as claimed in any one of claims 1 to 7.

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