Gas-supply system and method

A gas-supply system includes a gas container filled with gas, a gas flow controller coupled to the gas container via a first tube, and an operation device electrically connected to the gas flow controller. The gas-supply system further includes a pressure transducer installed on a second tube connected to the gas flow controller and configured to generate a pressure signal to the operation device according to the pressure of the gas in the second tube. The operation device is configured to generate a control signal to the gas flow controller according the pressure signal, and the gas flow controller is configured to adjust the flow rate of the gas in the second tube according to the control signal.

BACKGROUND

Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic apparatuses. Semiconductor devices are fabricated by various semiconductor processes. However, since semiconductor devices with smaller size and greater performance are in constant demand, some semiconductor processes are improved and modified.

In an epitaxy process of semiconductor manufacturing, a high-pressure liquefied gas, such as HCl and Cl2, is utilized. Usually, the high-pressure liquefied gas is transmitted to the epitaxy apparatus at a very high pressure, to satisfy the flow rate and pressure requested by the epitaxy apparatus.

In another epitaxy process, a low-pressure liquefied gas is utilized. Due to the characteristics of the low-pressure liquefied gas, the gas cannot be transmitted at a high pressure, and may not satisfy the flow rate and pressure used by the epitaxy apparatus.

DETAILED DESCRIPTION

FIG. 1is a schematic view of a gas-supply system1aand a semiconductor apparatus2in accordance with some embodiments of the disclosure. The gas-supply system1asupplies gas to a semiconductor apparatus2.

The gas-supply system1aincludes gas containers10and gas regulators20a. The gas containers10are filled with gas. The gas containers10communicate with the semiconductor apparatus2via a tube T1, and supply the gas to the semiconductor apparatus2via the tube T1. The gas regulators20aare disposed on the tube T1. In some embodiments, a number of the valves E1are disposed on the tube T1. Each of the gas containers10is selectively to supply the gas to the semiconductor apparatus2via the valves E1. For example, when one of the gas containers10is empty, the valve E1connected to the empty gas container10is switched off, and another valve E1connected to another gas container10having the gas is switched on. Furthermore, the gas is continuously supplied to the semiconductor apparatus2from the gas container10having the gas, and the empty gas container10can be replaced by a new gas container.

In some embodiments, the gas containers10are high-pressure gas cylinders. The pressure in the gas containers10is in a range from about 500 PSIG (Pounds per Square Inch Gauge) to about 2500 PSIG. For example, the pressure in the gas containers10is detected by a pressure sensor (not shown), and is about 2000 PSIG. In some embodiments, the gas is a high-pressure liquefied gas, such as CF4, N2O, Cl2, NH3, HCl, CO2, HBr, or SF6. Further, the high-pressure liquefied gas is not liquefied in a low-pressure environment, such as lower than about 100 PSIG. Therefore, the high-pressure liquefied gas released from the gas containers10is not liquefied in the tube T1, or in the downstream of the gas regulators20a.

In some embodiments, the semiconductor apparatus2is an epitaxy apparatus. When the semiconductor apparatus2consumes the gas, the gas flows into the semiconductor apparatus2from the gas containers10due to the pressure in the gas containers10. The gas regulators20acan be adjusted manually to control a delivery pressure in the tube T1.

FIG. 2is a diagram of flow rate versus delivery pressure of the semiconductor apparatus2inFIG. 1in accordance with some embodiments of the disclosure. The working pressure of the high-pressure liquefied gas utilized by the semiconductor apparatus2is in a range of from about 60 PSIG to about 70 PSIG. The flow rate of the gas utilized by the semiconductor apparatus2is from about 5 SLPM (Stand Liter per Minute) to about 100 SLPM. Referring to the curve C1, as shown inFIG. 2, the delivery pressure of the high-pressure liquefied gas in the semiconductor apparatus2is within a range of from about 60 PSIG to about 70 PSIG. Therefore, the semiconductor apparatus2works fine with the high-pressure liquefied gas.

However, in another epitaxy process, the gas is replaced by a low-pressure liquefied gas, and the gas containers10are lower-pressure gas cylinders for containing the low-pressure liquefied gas. For example, the working pressure of the gas utilized by the semiconductor apparatus2is in a range of from about 5 PSIG to about 7 PSIG, and the flow rate of the gas utilized by the semiconductor apparatus2is from about 5 SLPM (Stand Liter per Minute) to about 100 SLPM.

The low-pressure liquefied gas includes ClF3, BCl3, SiH2Cl2(Dichlorosilane, DCS), C4F6, C5F8, HF or WF6. The low-pressure liquefied gas may be liquefied if the gas pressure exceeds a saturation vapor pressure at gas room temperature. The gas room temperature is in a range from about 20° C. to about 25° C. The low-pressure liquefied gas may be liquefied in a range from about 30 PSIG to about 100 PSIG. Therefore, the pressure in the tube T1is in a range from about −5 PSIG to about 15 PSIG at the gas room temperature to prevent the low-pressure liquefied gas from being liquefied.

Referring to the curve C2, as shown inFIG. 2, when the flow rate of the low-pressure liquefied gas in the tube T1is increased from about 0 SLPM to about 4 SLPM, the delivery pressure of the low-pressure liquefied gas in the semiconductor apparatus2is quickly decreased from about 6 PSIG to about 0 PSIG. The reason for this situation is that the gas regulator20ahas a high flow resistance. The flow resistance of the gas regulator20ais a result of the gas flowing through a poppet and a diaphragm (not shown) in the gas regulator20a. Due to flow resistance, the additional flow rate of the gas in the gas regulator20ainduces additional delivery pressure drop.

In some embodiments, if the delivery pressure is lower than a predetermined working pressure of the semiconductor apparatus2at a corresponding flow rate, such as at least 5 SLPM, of the low-pressure liquefied gas, the semiconductor apparatus2stops working.

FIG. 3is a schematic view of a gas-supply system1in accordance with some embodiments of the disclosure. The gas-supply system1includes gas containers10, gas flow controllers20, a buffer tank30, a pressure transducer40, and an operation device50. The gas is transmitted from the gas containers10, under the gas flow controllers20, and via the buffer tank30to the semiconductor apparatus2.

In some embodiments, the gas container10is a low-pressure liquefied gas cylinder. The pressure in the gas container10is in a range from about −10 PSIG to about 15 PSIG at the gas room temperature. The gas containers10are filled with gas and liquid, and the liquid naturally vaporizes to the gas at the gas room temperature. The gas is the low-pressure liquefied gas, such as DCS.

The gas flow controllers20are coupled to the gas containers10. The gas flow controllers20are a mass-flow controller configured to measure and control the flow rate of the gas flowing into the buffer tank30. The gas flow controllers20each adjust the flow rate of the gas to the buffer tank30. The buffer tank30is configured to provide a stable pressure of the gas to the semiconductor apparatus2. The buffer tank30is coupled to the gas flow controllers20and receives the gas from the gas container10via the gas flow controllers20. The semiconductor apparatus2is coupled to the buffer tank30and receives the gas from the buffer tank30.

In some embodiments, the gas flow controllers20are coupled with the gas containers10via a tube T2. The buffer tank30is coupled with the gas flow controllers20via a tube T3. The buffer tank30receives the gas from the gas container10via the tube T2, the gas flow controller20, and the tube T3. The semiconductor apparatus2is communicated with buffer tank30with a tube T4and receives the gas from the buffer tank30via the tube T4.

The pressure transducer40is disposed on the buffer tank30. The pressure transducer40detects the pressure in the buffer tank30and generates a pressure signal S1to the operation device50according to the pressure of the gas in the buffer tank30.

The operation device50is electrically connected to the gas flow controllers20and the pressure transducer40. In some embodiments, the operation device50is a computer. The operation device50generates a control signal S2to the gas flow controllers20according to the pressure signal S1, and the gas flow controllers20adjust the flow rate of the gas according to the control signal S2.

In some embodiments, the gas-supply system1further includes heating devices60. The heating device60heats the corresponding gas containers10, and keeps the temperature of the gas in the gas container10in a range of from about 30° C. to about 45° C. For illustration, the temperature of the gas in the gas container10is detected by a thermometer (not shown), and is about 40° C. In some embodiments, the environment temperature is in a range of from about 20° C. to about 24° C., and the ignition temperature of the gas is a range of from about 52° C. to about 58° C. The environment temperature is defined as the temperature around the gas-supply system1and the semiconductor apparatus2. In some embodiments, the environment temperature is about 22° C., and the ignition temperature of the gas is about 55° C.

When the temperature of the gas in the gas containers10increases, the pressure in the containers10increases. However, a higher temperature may cause the gas to ignite. In some embodiments, the temperature of the gas in the gas containers10is limited to being lower than the ignition temperature of the gas.

In some embodiments, the temperature of the gas in the buffer tank30is in a range from about 20° C. to about 25° C. For illustration, the temperature of the gas in the buffer tank30is detected by a thermometer (not shown) and is about 22° C., substantially equal to the environment temperature. In some embodiments, the pressure in the buffer tank30is in a range from about 5 PSIG to 7 PSIG. In such a condition, the gas may not be liquefied in the buffer tank30and in the tube T4.

FIG. 4is a schematic view of a gas flow controller20in accordance with some embodiments of the disclosure. The gas flow controller20includes a housing21, a first channel22, a second channel23, a flow-rate transducer24, a control module25, and a valve mechanism26. The first channel22, the second channel23, the flow-rate transducer24, the control module25, and the valve mechanism26are disposed in the housing21. The first channel22is coupled to the gas container10and the buffer tank30, as shown inFIG. 3. In some embodiments, the first channel22is communicated with the tube T2and T3.

The first channel22has a first section221and a second section222. The cross-sectional area of the first section221is greater than the cross-sectional area of the second section222. The cross-sectional area of the first section221is greater than the cross-sectional area of the second channel23.

The two ends of the second channel23are connected to the first section221of the first channel22. The flow-rate transducer24is disposed on the second channel23. The flow-rate transducer24is configured to detect the flow rate of the gas in the second channel23, and generate a measuring signal S3according to the flow rate of the gas in the second channel23. In some embodiments, the flow-rate transducer24includes a first temperature transducer241and a second temperature transducer242. The first temperature transducer241and the second temperature transducer242are separated from each other and detect the temperature of the second channel23at different locations. When the gas flows in the first channel22and the second channel23, the temperatures detected by the first temperature transducer241and the second temperature transducer242are different.

The control module25is electrically connected to the flow-rate transducer24, the valve mechanism26, and the operation device50(as shown inFIG. 3). The control module25is configured to receive the measuring signal S3.

In some embodiments, the flow rate of the gas can be calculated by the control module25according to the difference of the temperatures detected by the first temperature transducer241and the second temperature transducer242. For example, when the gas flows in the first channel22, the temperature detected by the temperature transducer241is about 22.03° C., and the temperature detected by the temperature transducer242is about 22.04° C. The difference of the temperatures of the temperature transducer241and the temperature transducer242is about 0.01° C., which corresponds to the flow rate of the gas.

In addition, when the first channel22is blocked by the valve mechanism26, the gas does not flow through the second section222of the first channel22. The temperatures detected by the first temperature transducer241and the second temperature transducer242are the same. Therefore, the control module25determines that the flow rate of the gas is zero due to the same temperatures being detected by the first temperature transducer241and the second temperature transducer242.

The valve mechanism26is disposed on the second section222of the first channel22. The valve mechanism26is controlled by the control module25. The flow rate of the gas is adjusted according to the position of the valve mechanism26in the second section222.

In some embodiments, the valve mechanism26includes a piezoelectric element261. The volume of the piezoelectric element261changes according the applied voltage V1on the piezoelectric element261. The position of the valve mechanism26is adjusted according to the volume of the piezoelectric element261. The control module25applies a corresponding voltage V1to the piezoelectric element261according to the control signal S2, and the volume of the piezoelectric element261is adjusted by the voltage V1. For example, when the volume of the piezoelectric element261increases, the flow rate of the gas in the first channel22decreases.

FIG. 5is a flow chart of a gas-supply method of the gas-supply system1as shown inFIG. 3in accordance with some embodiments of the disclosure. In step S101, the gas-supply system1and the semiconductor apparatus2are provided. In the gas-supply system1, the buffer tank30is coupled to the gas container10and the semiconductor apparatus2. The semiconductor apparatus2receives the gas from the buffer tank30.

In step S103, the pressure transducer40detects the pressure of the gas in the buffer tank30, and generates a pressure signal S1to the operation device50. In step S105, the operation device50generates a control signal S2according to a pressure signal S1and a predetermined pressure value.

The operation device50controls the gas flow controller20to keep the pressure of the gas in the buffer tank30in a predetermined pressure range. For example, the predetermined pressure range is in a range of from about 5 PSIG to about 7 PSIG.

In some embodiments, the predetermined pressure value is set in the operation device50, and the pressure signal S1corresponding to the pressure in the buffer tank30includes an active pressure value. If the active pressure value is lower than the predetermined pressure value, the operation device50generates a control signal S2to the gas flow controller20according to the difference between the active pressure value and the predetermined pressure value.

In step S107, the control module25of the gas flow controller20adjusts the flow rate of the gas flowing into the buffer tank30from the gas container10according to the control signal S2. In some embodiments, the flow-rate transducer24detects the flow rate of the gas flowing into the buffer tank30and generates a measuring signal S3to the control module25. The control module25of the gas flow controller20adjusts the flow rate of the gas flowing into the buffer tank30from the gas container10according to the control signal S2and the measuring signal S3. After the gas flows into the buffer tank30, the pressure in the buffer tank30gradually rises to the predetermined pressure range. In general, if the active pressure value is lower than the predetermined pressure value, the flow rate of the gas flowing into the buffer tank30increases.

If the pressure of the gas in the buffer tank30is in a predetermined pressure range, the operation device50continually fine-tunes the flow rate of the gas flowing into the buffer tank30to keep the pressure of the buffer tank30at about the predetermined pressure value. If the pressure of the gas in the buffer tank30is higher than the predetermined pressure range, the flow rate of the gas flowing into the buffer tank30is set to zero or substantially zero. Therefore, the gas flow controller20controls the valve mechanism26to close the second section222of the first channel22to block the gas flowing.

In step S109, the semiconductor apparatus2receives the gas from the buffer tank30. When the semiconductor apparatus2consumes the gas, the gas flows from the buffer tank30. In general, the semiconductor apparatus2does not continually consume the gas, and the quantity of the gas consumed by the semiconductor apparatus2depends on different semiconductor processes. As a result, the pressure in the buffer tank30is not constant. Therefore, by the gas-supply system1and the gas-supply method, the pressure in the buffer tank30can be kept in the predetermined pressure range.

Further, in some embodiments, the volume of the buffer tank30is at least two times greater than the volume of the gas container10. Since the gas transmitted from the buffer tank30to the semiconductor apparatus2does not pass through any gas regulator, the flow resistance of the gas flowing to the semiconductor apparatus2is lower. Therefore, although the flow rate of the gas consumed by the semiconductor apparatus2changes, the delivery pressure and the flow rate of the gas applied to the semiconductor apparatus2satisfies the requirements of the semiconductor apparatus2.

FIG. 6is a schematic view of a gas-supply system1in accordance with some embodiments of the disclosure. The buffer tank30inFIG. 3is excluded inFIG. 6. The gas is transmitted from the gas containers10to the semiconductor apparatus2via the gas flow controllers20.

The gas flow controllers20are coupled to the gas containers10via the tubes T5. In some embodiments, each of the tubes T5is connected to one of the gas flow controllers20and one of the gas containers10. In some embodiments, each of the tubes T5is connected to one of the gas flow controllers20and at least two gas containers10.

The gas flow controllers20are configured to control the flow rate of the gas flowing into the semiconductor apparatus2via a tube T6. In some embodiments, the tube T6is connected to the semiconductor apparatus2and the gas flow controllers20. The semiconductor apparatus2is coupled to the gas flow controllers20via the tube T6and is configured to receive the gas from the tube T6.

The pressure transducer40is installed on the tube T6. The pressure transducer40detects the pressure in the tube T6and generates a pressure signal S1to the operation device50according to the pressure of the gas in the tube T6.

The operation device50is electrically connected to the gas flow controllers20and the pressure transducer40. The operation device50generates a control signal S2to the gas flow controllers20according to the pressure signal S1, and the gas flow controllers20adjust the flow rate of the gas in the tube T6according to the control signal S2.

FIG. 7Ais a schematic view of a gas flow controller20in accordance with some embodiments of the disclosure. The gas flow controller20includes a housing21and a valve mechanism26. The housing21is disposed on the tube T6. In some embodiments, the housing21covers a section T61of the tube T6. The section T61and the housing21are formed as a single piece.

The valve mechanism26is disposed in the housing21. The position of the valve mechanism26in the section T61of the tube T6is according to the control signal. The flow rate of the gas in the tube T6is adjusted according to the position of the valve mechanism26in the section T61of the tube T6. The flow rate of the gas in the tube T6is increased when the volume of the valve mechanism26in the section T61is decreased. The flow rate of the gas in the tube T6is decreased when the volume of the valve mechanism26in the section T61is increased.

In some embodiments, the valve mechanism26is a proportional valve, such as an electric proportional valve. In some embodiments, the valve mechanism26includes a piezoelectric element261. The position of the valve mechanism26is adjusted according to the volume of the piezoelectric element261. The volume of the piezoelectric element261is adjusted according to the control signal S2. For example, when the volume of the piezoelectric element261increases, the flow rate of the gas in the tube T6decreases.

FIG. 7Bis a schematic view of a gas flow controller20in accordance with some embodiments of the disclosure. In some embodiments, the pressure transducer40is integrated into the gas flow controller20. The pressure transducer40is disposed in the housing21. The pressure transducer40contacts the gas in the tube T6within the housing21.

FIG. 7Cis a schematic view of a gas flow controller20in accordance with some embodiments of the disclosure. In some embodiments, the valve mechanism26includes a core262, a coil263, and an elastic element264. The core262is moveably disposed in the housing21. The core262is made from a magnetic material.

The coil263is disposed in the housing21, and around the core262. When power is applied to the coil263, the coil263generates a magnetic force to move the core262along a first direction D1. The magnetic force is changed according to the strength of the power. The strength of the power applied to the coil263is according to the control signal S2.

The elastic element264is disposed in the housing21. The elastic element264is configured to apply an elastic force to move the core262along a second direction D2. In some embodiments, the second direction D2is an inverse direction of the first direction D1.

The position of the core262is adjusted according to the magnetic force generated by the coil263, and the strength of the magnetic force is according to the control signal S2. The flow rate of the gas in the tube T6is adjusted according to the position of the core262in the section T61of the tube T6.

FIG. 8is a flow chart of a gas-supply method of the gas-supply system1as shown inFIG. 6in accordance with some embodiments of the disclosure. In step S201, the gas-supply system1and the semiconductor apparatus2are provided. In the gas-supply system1, the gas flow controllers20are coupled to the gas containers10via the tube T5, and coupled to the semiconductor apparatus2via the tube T6. The semiconductor apparatus2receives the gas from the tube T6.

In step S203, the pressure transducer40detects the pressure of the gas in the tube T6, and generates a pressure signal S1to the operation device50. In step S205, the operation device50generates a control signal S2according to the pressure signal S1and a predetermined pressure value.

In some embodiments, the predetermined pressure value is set in the operation device50, and the pressure signal S1corresponding to the pressure in the tube T6includes an active pressure value. In some embodiments, when the active pressure value is lower than the predetermined pressure value, the operation device50generates a control signal S2to the gas flow controller20according to the difference between the active pressure value and the predetermined pressure value. For example, the difference is greater, and the flow rate of the gas in the tube T6is greater according to the control signal S2.

In step S107, the operation device50controls the gas flow controller20to keep the pressure of the gas in the tube T6in a predetermined pressure range. The gas flow controller20adjusts the flow rate of the gas in the tube T6according to the control signal S2. If the active pressure value is lower than the predetermined pressure value, the flow rate of the gas in the tube T6is increased by the operation device50. If the active pressure value is higher than the predetermined pressure value, the flow rate of the gas in the tube T6is decreased by the operation device50.

If the pressure of the gas in the tube T6is in a predetermined pressure range, the operation device50continually fine-tunes the flow rate of the gas in the tube T6to keep the pressure of the tube T6at about the predetermined pressure value. If the pressure of the gas in the tube T6is higher than the predetermined pressure range, the flow rate of the gas in the tube T6is set to zero or substantially zero. In some embodiments, the gas flow controller20controls the valve mechanism26to block the gas in the section T61flowing.

In step S209, the semiconductor apparatus2receives the gas from the tube T6.

FIG. 9is a diagram of flow rate versus delivery pressure of the semiconductor apparatus1in accordance with some embodiments of the disclosure. The flow rate of the lower pressure liquefied gas utilized by the semiconductor apparatus2is from 10 SLPM to 100 SLPM. The working pressure of the gas utilized by the semiconductor apparatus2is in a range from about 5 PSIG to about 7 PSIG. Referring to the curve C3, as shown inFIG. 9, the delivery pressure of the low-pressure liquefied gas in the semiconductor apparatus2is within the working pressure. Therefore, the semiconductor apparatus2works fine with the low-pressure liquefied gas.

Some embodiments for a gas-supply system are provided. The gas-supply system keeps the pressure of a gas being transferred to semiconductor apparatus in a predetermined pressure range. Further, the flow rate and pressure of low-pressure liquefied gas utilized by the semiconductor apparatus is satisfied by the gas-supply system.

In some embodiments, a gas-supply system is provided. The gas-supply system includes a gas container filled with gas, a gas flow controller coupled to the gas container via a first tube, and an operation device electrically connected to the gas flow controller. The gas-supply system further includes a pressure transducer installed on a second tube connected to the gas flow controller and configured to generate a pressure signal to the operation device according to the pressure of the gas in the second tube. The operation device is configured to generate a control signal to the gas flow controller according to the pressure signal, and the gas flow controller is configured to adjust a flow rate of the gas in the second tube according to the control signal.

In some embodiments, a gas-supply system is provided. The gas-supply system includes a gas container filled with gas and a gas flow controller coupled with the gas container via a first tube. The gas is a low-pressure liquefied gas. The gas-supply system also includes a pressure transducer installed on a second tube connected to the gas flow controller and configured to generate a pressure signal according to a pressure of the gas in the second tube. The gas-supply system further includes an operation device receiving the pressure signal and configured to generate a control signal to the gas flow controller according the pressure signal and a predetermined pressure value. The gas flow controller is configured to adjust the flow rate of the gas in the second tube according to the control signal to keep the pressure of the gas in the in the second tube within a predetermined pressure range. The semiconductor apparatus is coupled to the gas flow controller via the second tube and is configured to receive the gas from the second tube.

In some embodiments, a gas-supply method is provided. The method includes providing a gas flow controller coupled to a gas container via a first tube and detecting pressure of a gas in a second tube coupled to the gas flow controller and generating a pressure signal. The method further includes generating a control signal according the pressure signal and a predetermined pressure value. The method further includes adjusting a flow rate of a gas flowing in the second tube via the gas flow controller according to the control signal, and receiving the gas from the second tube.