XeF2 etching equipment
By designing an XeF2 etching device that includes a loading cavity, a transport cavity, a deposition self-assembly monolayer module, and an XeF2 etching process module, the problems of Si surface oxide formation, excessively high water vapor pressure in the etching cavity, and etching non-uniformity were solved, achieving a highly efficient and uniform etching and deposition process, and improving the quality and production capacity of microelectronic products.
Patent Information
- Application Number
- CN202422401871.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-09-30
AI Technical Summary
Existing XeF2 etching technology suffers from problems such as reduced etching rate and uniformity due to the formation of oxides on the Si surface, excessively high water vapor pressure in the etching chamber affecting the etching effect, waste of XeF2 gas and uneven etching, and lag in the movement of etched components, which affect the quality and production capacity of microelectronic products.
A XeF2 etching apparatus was designed, comprising a loading chamber, a transport chamber, a deposition self-assembled monolayer module, a plasma etching chamber, and a XeF2 etching process module, to achieve vacuum loading of workpieces/wafers, surface plasma pre-cleaning, XeF2 etching, and SAM deposition, ensuring the uniformity of the etching and deposition processes.
Vacuum treatment and plasma pre-cleaning reduce the impact of surface impurities, improve the uniformity and rate of etching and deposition, reduce XeF2 gas waste, and ensure the smoothness of the etched structure and product quality.
Smart Images
Figure CN223501815U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of etching technology, and more specifically to an XeF2 etching device. Background Technology
[0002] XeF2 is a white solid in its unevaporated state, with a saturated vapor pressure of 3.8 Torr at room temperature. It can chemically react with Si at room temperature to form gaseous Xe, SiF4, and other compounds: 2XeF2 + Si → 2Xe(g) + SiF4(g). XeF2 is widely used in microelectronic device manufacturing to etch Si materials, and it can also etch materials such as Mo, W, Ti, Zr, V, and Ta.
[0003] Using XeF2 to etch Si has several advantages over wet etching and other dry etching methods such as CF4, SF6, and Cl2:
[0004] 1. This etching process does not require external energy (such as heating, ion sources, etc.), and the etching equipment and methods are simple.
[0005] 2. This is a dry etching process. The etching reactants are all volatile and can be removed by a vacuum system. With the help of exhaust gas combustion treatment, there is almost no etching pollution.
[0006] 3. This etching process has a high selectivity for commonly used materials in microelectronic device manufacturing, such as SiO2, photoresist, and Al thin film, typically >1000:1. Therefore, this etching process will not damage these materials and can also be used as a mask. It also helps to etch Si "cleanly and thoroughly", making the formed structure "free-standing" and basically not "sticking" to the substrate.
[0007] 4. This etching is an isotropic etching; it can etch in all directions of Si material, making it very suitable for "hollowing out" (etching) the Si material under the surface film to form a suspended structure of the surface film.
[0008] 5. This etching process has a very high etching rate, typically reaching several µm / min.
[0009] However, many problems have also been found in the use of XeF2 to etch Si:
[0010] 1. When samples are exposed to air, SiO2 typically forms on the Si surface to be etched. This severely reduces the etching rate and uniformity of Si, and may even cause etching to stop. Therefore, before etching XeF2, the sample is usually soaked in HF to remove surface SiO2, then rinsed with deionized water, dried, and then placed in the etching equipment. This significantly reduces the precision and reliability of the etching process, which is detrimental to the continuous industrial production of microelectronic products.
[0011] 2. At the same time, if the residual water vapor pressure in the etching chamber is too high, it will cause the F and H2O generated during the XeF2 etching process to react chemically and produce HF, which will etch the SiO2 layer used as a mask. Therefore, the water vapor bias pressure in the etching chamber must be kept extremely low.
[0012] 3. XeF2 is extremely expensive. Currently, XeF2 etching equipment typically employs two etching methods: continuous etching and pulsed etching. The former continuously introduces XeF2 gas into the etching chamber, maintaining gas pressure and controlling etching time to achieve the desired etching thickness and other requirements. The latter introduces XeF2 gas into the etching chamber, stopping the gas introduction and closing the evacuation valve when a preset pressure is reached. The pressure in the chamber increases during the XeF2 gas etching of Si. When the preset pressure is reached, the evacuation valve is opened to create a vacuum. When the vacuum reaches a predetermined value, the evacuation valve is closed, and XeF2 gas is reintroduced into the etching chamber, forming a cycle. Typically, multiple cycles (1~100) are required to achieve the desired etching thickness and other requirements. In both methods, any XeF2 gas not used in the etching process is removed by the vacuum pump, resulting in waste. Meanwhile, due to the diffusion of gas between the expansion cavity and the etching cavity, once pressure equilibrium is reached, the gas flow rate decreases, which is very detrimental to the uniformity of etching.
[0013] 4. Although XeF2 etching can basically solve the problem of "adhesion" between the etched structure and the substrate, in actual production, the etched parts still have a "stiffness" phenomenon when they move. That is, the etching ultimately fails to form a very smooth, free-standing suspended part, which affects the quality and production capacity of the product. Utility Model Content
[0014] To address the shortcomings of existing technologies, this invention provides an XeF2 etching apparatus that can vacuum load and transfer workpieces / wafers, and perform surface plasma pre-cleaning, XeF2 etching, further surface plasma pre-cleaning, SAM deposition, and loading of the wafer, thereby completing the entire XeF2 etching and SAM deposition process, and ensuring uniformity in both XeF2 etching and SAM deposition.
[0015] To achieve the above objectives, the present invention provides the following technical solution:
[0016] A XeF2 etching apparatus, comprising:
[0017] The loading chamber is used to load the workpiece or wafer that needs to be etched, and a first vacuum valve is provided between it and the outside world.
[0018] The transport cavity is equipped with a robotic arm, which is connected to the loading cavity, the deposition self-assembly monolayer module, the plasma etching cavity, and the XeF2 etching process module. A second vacuum valve is provided between the transport cavity and the loading cavity, the deposition self-assembly monolayer module, the plasma etching cavity, and the XeF2 etching process module.
[0019] A self-assembled monolayer module for deposition, comprising a deposition chamber, for SAM deposition on a workpiece or wafer;
[0020] Plasma etching chamber, which is used to perform plasma etching on workpieces or wafers;
[0021] The XeF2 etching process module includes an XeF2 etching chamber for XeF2 etching of workpieces or wafers.
[0022] Furthermore, the XeF2 etching process module also includes an XeF2 gas source, an N2 gas source, an expansion chamber, a circulating pump, and a first vacuum pump group. The XeF2 gas source is connected to the expansion chamber via pipeline one, and valve one is installed on pipeline one. The N2 gas source is connected to pipeline one, the expansion chamber, and the XeF2 etching chamber via pipeline two, and valves five, six, seven, and a gas flow meter one are respectively installed between pipeline two and pipeline one, the expansion chamber, the XeF2 etching chamber, and the N2 gas source. The expansion chamber is connected to the XeF2 etching chamber via pipeline three. The XeF2 etching chamber is connected to the transport chamber, and the XeF2 etching chamber is connected to the circulation pump and the first vacuum pump group through the fourth and fifth pipes respectively. The fourth pipe is equipped with a valve eight, and the fifth pipe is equipped with a valve three. The expansion chamber is connected to the first vacuum pump group through the sixth pipe, and the sixth pipe is equipped with a valve four. The circulation pump is connected to the expansion chamber and the XeF2 etching chamber through the seventh and eighth pipes respectively. The seventh pipe is equipped with a valve nine, and the eighth pipe is equipped with a valve ten.
[0023] Furthermore, the deposition self-assembled monolayer module also includes a carrier gas source, a first storage tank, a second storage tank, and a second vacuum pump group. The carrier gas source is connected to the deposition chamber via pipeline eleven, and a valve eleven is installed on pipeline eleven. The carrier gas source is connected to the first storage tank and the second storage tank via pipeline twelve, and a valve twelfth and a gas flow meter second are installed between pipeline twelfth and the first storage tank. A valve thirteenth and a gas flow meter third are installed between pipeline twelfth and the second storage tank. The first storage tank and the second storage tank are connected to the deposition chamber via pipeline thirteen. The deposition chamber is connected to the transport chamber and connected to the second vacuum pump group via pipeline fourteen, and a valve fourteen is installed on pipeline fourteen. Both the first storage tank and the second storage tank are equipped with heating devices.
[0024] Furthermore, the deposition self-assembly monolayer module also includes a carrier gas source, a steam generator, a first storage tank, a second storage tank, and a second vacuum pump group. The carrier gas source is connected to the evaporator via pipeline 15, and a gas flow meter 4 is installed on pipeline 15. The carrier gas source is connected to the first and second storage tanks via pipeline 16, and a gas flow meter 5 is installed between the carrier gas source and pipeline 16. Valves 15 and 16 are respectively installed between the first and second storage tanks and pipeline 16. The first and second storage tanks are connected to the evaporator via pipeline 17, and liquid flow meters 1 and 2 are respectively installed between the first and second storage tanks and pipeline 17. The evaporator is connected to the deposition chamber via pipeline 18. The deposition chamber is connected to the transport chamber and connected to the second vacuum pump group via pipeline 19, and a valve 17 is installed on pipeline 19.
[0025] Compared with the prior art, the beneficial effects of this utility model are:
[0026] This invention, by setting up an loading cavity, a transport cavity, a self-assembled monolayer deposition module, a plasma etching cavity, and an XeF2 etching process module, can perform vacuum loading and transport of workpieces / wafers. The wafer undergoes surface plasma pre-cleaning, XeF2 etching, further surface plasma pre-cleaning, SAM deposition, and loading, thus completing the entire XeF2 etching and SAM deposition process. Both XeF2 etching and SAM deposition can ensure uniformity. Furthermore, surface plasma pre-cleaning is performed before XeF2 etching and SAM deposition to reduce the influence of surface impurities and improve the uniformity and rate of etching and deposition. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:
[0028] Figure 1 This is a schematic diagram of the structure of an XeF2 etching device;
[0029] Figure 2 This is a schematic diagram of the XeF2 etching process module;
[0030] Figure 3 This is a schematic diagram of an embodiment of a self-assembled monolayer module.
[0031] Figure 4 This is a schematic diagram of Example 2, which illustrates the deposition of a self-assembled monolayer module.
[0032] The following are labeled in the figure: 1. Loading chamber; 2. Transport chamber; 3. XeF2 etching process module; 4. Plasma etching chamber; 5. Deposition self-assembled monolayer module; 501. First storage tank; 502. Second storage tank; 503. Deposition chamber; 504. Heating device; 6. Robotic arm. Detailed Implementation
[0033] In the description of this utility model, it should be noted that the directional terms such as "center", "horizontal (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this utility model.
[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this utility model, "several" or "a number" means two or more, unless otherwise explicitly specified.
[0035] A type of XeF2 etching apparatus, such as Figure 1 As shown, it includes:
[0036] The loading cavity 1 is used to load the workpiece or wafer to be etched, and is equipped with a first vacuum valve between it and the outside world.
[0037] The transport cavity 2 is equipped with a robotic arm 6, which is connected to the loading cavity 1, the deposition self-assembled monolayer module 5, the plasma etching cavity 4 and the XeF2 etching process module 3 respectively. A second vacuum valve is provided between the transport cavity 2 and the loading cavity 1, the deposition self-assembled monolayer module 5, the plasma etching cavity 4 and the XeF2 etching process module 3.
[0038] A self-assembled monolayer deposition module 5, comprising a deposition chamber 503, is used for SAM deposition on a workpiece or wafer.
[0039] Plasma etching chamber 4 is used to perform plasma etching on workpieces or wafers;
[0040] XeF2 etching process module 3, which includes an XeF2 etching cavity for XeF2 etching of workpieces or wafers;
[0041] The method of using the XeF2 etching equipment includes the following steps:
[0042] S1. Open the first vacuum valve, place the wafer into the loading chamber 1, then close the first vacuum valve and evacuate the loading chamber 1.
[0043] S2. When the vacuum level in the loading chamber 1 reaches the predetermined value, the second vacuum valve between the loading chamber 1 and the transport chamber 2 is opened, and the robotic arm 6 in the transport chamber 2 loads the wafer into the transport chamber 2. Then the second vacuum valve between the transport chamber 2 and the loading chamber 1 is closed.
[0044] S3. Open the second vacuum valve between the plasma etching chamber 4 and the transport chamber 2. The robotic arm 6 in the transport chamber 2 loads the wafer into the plasma etching chamber 4. Then close the second vacuum valve between the plasma etching chamber 4 and the transport chamber 2.
[0045] S4. Apply power or other means to the plasma etching chamber to generate plasma and perform surface plasma pre-cleaning on the wafer.
[0046] S5. After plasma pre-cleaning is completed, open the second vacuum valve between the plasma etching chamber and the transport chamber 2. The robot arm 6 takes out the wafer. At the same time, open the second vacuum valve between the XeF2 etching chamber and the transport chamber 2. The robot arm 6 in the transport chamber 2 loads the wafer into the XeF2 etching chamber. Then close the second vacuum valve between the XeF2 etching chamber and the transport chamber 2.
[0047] S6. Within the XeF2 etching chamber, perform any one of multiple undiluted pulse etching processes, multiple undiluted continuous etching processes, or multiple undiluted continuous etching processes on the wafer to complete the XeF2 etching of the wafer.
[0048] S7. After XeF2 etching is completed, the second vacuum valve between the XeF2 etching chamber and the transport chamber 2 is opened, and the robot arm 6 takes out the wafer. At the same time, the second vacuum valve between the plasma etching chamber and the transport chamber 2 is opened, and the robot arm 6 puts the wafer into the plasma etching chamber. In the plasma etching chamber, power is applied to generate plasma, and the wafer is pre-cleaned with plasma again.
[0049] S8. After plasma pre-cleaning is completed, the second vacuum valve between the plasma etching chamber and the transport chamber 2 is opened, and the robot arm 6 takes out the wafer. At the same time, the second vacuum valve between the deposition chamber 503 and the transport chamber 2 is opened, and the robot arm 6 puts the wafer into the deposition chamber 503.
[0050] S9. In the deposition chamber 503, SAM material is deposited on the wafer using the bubble method or the vaporization method.
[0051] After S10 and SAM deposition are completed, the second vacuum valve between the deposition chambers 503 and 503 is opened, and the robot arm 6 takes out the wafer. At the same time, the second vacuum valve between the deposition chamber 503 and the loading chamber 1 is opened, and the robot arm 6 puts the wafer into the loading chamber 1.
[0052] S11. Once the vacuum in the loading cavity 1 is broken, the wafer can be removed, completing the entire XeF2 etching and SAM deposition process.
[0053] Preferably, the plasma etching chamber 4 can use plasma to etch SiO2 oxide, moisture, and other impurities from the Si surface. Since the Si surface is etched in a vacuum and remains in a vacuum state during subsequent transport and processing, secondary contamination of the sample by the atmosphere (formation of SiO2 and adsorption of moisture and other impurities on the surface) is avoided. This allows the "fresh" Si surface to be directly etched by XeF2, ensuring the uniformity and rate of etching. Argon gas (Ar) is usually introduced, and plasma can be generated using known methods such as CCP (capacitively coupled plasma), ICP (inductively coupled plasma), Microwave, and other remote ion sources to bombard the workpiece / wafer.
[0054] Preferred, such as Figure 2As shown, the XeF2 etching process module 3 further includes an XeF2 gas source, an N2 gas source, an expansion chamber, a circulating pump, and a first vacuum pump group. The XeF2 gas source is connected to the expansion chamber via pipeline one, and valve one is installed on pipeline one. The N2 gas source is connected to pipeline one, the expansion chamber, and the XeF2 etching chamber via pipeline two, and valves five, six, seven, and a gas flow meter one are respectively installed between pipeline two and pipeline one, the expansion chamber, the XeF2 etching chamber, and the N2 gas source. The expansion chamber is connected to the XeF2 etching chamber via pipeline three. The XeF2 etching chamber is connected to the transport chamber 2, and the XeF2 etching chamber is connected to the circulation pump and the first vacuum pump group through the fourth and fifth pipes respectively. The fourth pipe is equipped with valve eight, and the fifth pipe is equipped with valve three. The expansion chamber is connected to the first vacuum pump group through the sixth pipe, and the sixth pipe is equipped with valve four. The circulation pump is connected to the expansion chamber and the XeF2 etching chamber through the seventh and eighth pipes respectively. The seventh pipe is equipped with valve nine, and the eighth pipe is equipped with valve ten.
[0055] Specifically, the etching process of XeF2 includes two processes: "continuous" and "pulsed".
[0056] Preferably, a non-diluted continuous etching process includes the following steps:
[0057] 1) Valves one, two, and three are opened, while the remaining valves are closed. XeF2 gas enters the XeF2 etching chamber, and the timer starts timing. At the same time, valve three is continuously adjusted to make the pressure in the XeF2 etching chamber reach the specified value.
[0058] 2) When the set etching time is reached, close valves one and two, and fully open valve three to evacuate the etching chamber to a low vacuum.
[0059] A typical process flow can be:
[0060] Cy10-etch15s-3TorrX;
[0061] That is, 10 pulse cycles: each pulse etches for 15 seconds, and the etching pressure of XeF2 is 3 Torr.
[0062] Preferably, a dilution continuous etching process includes the following steps:
[0063] 1) Valves one, two, three, and five are opened, while the remaining valves are closed. XeF2 gas enters the XeF2 etching chamber, and the timer starts timing at the same time. At the same time, valve three is adjusted to make the pressure in the etching chamber reach the specified value.
[0064] 2) When the set etching time is reached, close valves one, two, and five, and fully open valve three to evacuate the XeF2 etching chamber to a low vacuum.
[0065] A typical process flow can be:
[0066] Cy10-etch15s-3TorrX-3TorrN;
[0067] That is, 10 pulse cycles: each pulse etch for 15 seconds, etching XeF2 gas pressure 3 Torr, N2 gas pressure 3 Torr.
[0068] Specifically, in practical applications, the "pulse" process is often used.
[0069] Preferably, a non-diluted pulse etching process includes the following steps:
[0070] 1) Once the valve is opened, all other valves are closed, and XeF2 gas enters the expansion chamber. When the gas pressure in the expansion chamber reaches a predetermined value (usually 5-10 Torr), the valve closes.
[0071] 2) Valves 2, 8, and 9 are opened, while the remaining valves are closed. At the same time, the timer starts. Since the etching chamber is initially in a vacuum state, XeF2 gas diffuses from the expansion chamber to the XeF2 etching chamber and performs chemical etching on the wafer inside the XeF2 etching chamber. Simultaneously, the circulation pump starts running to fully and evenly distribute the gas in the expansion chamber and the XeF2 etching chamber, which can improve the etching uniformity and the utilization rate of the etching gas. When the pressure inside the etching chamber reaches the predetermined value (usually 1-5 Torr), valves 2 and 9 close, valve 8 remains open, and valve 10 opens to continue the gas flow inside the XeF2 etching chamber until the timer reaches the predetermined time value.
[0072] 3) Valves two and three are opened, and the remaining valves are closed. The XeF2 gas in the expansion chamber and the XeF2 etching chamber is pumped away by the first vacuum pump group until the vacuum in the etching chamber reaches a predetermined value, usually <5e-5Torr.
[0073] 4) Valves two and three are closed, valve four is open, and the remaining valves are closed. The XeF2 gas in the expansion chamber is pumped away by the first vacuum pump group until the vacuum in the expansion chamber reaches the predetermined value, then valve four is closed.
[0074] Steps 1) to 4) above constitute a non-diluted pulse etching process. Typically, etching requires 1 to 100 pulse etching processes to complete wafer etching. It is also possible to pause between each pulse process (usually the pause time is 0-300 seconds) to reduce the substrate temperature. After all pulse processes are completed, if necessary, gas flow meter one can be turned on to introduce N2, and valves four and six can be opened to purge the expansion chamber; valves three and seven can be opened to purge the etching chamber.
[0075] A typical process flow can be:
[0076] Cy10-etch30s-3TorrX-0TorrN-10sCool3TorrN-Delay10s
[0077] That is, 10 pulse cycles: each pulse etches for 30 seconds, with an XeF2 gas pressure of 3 Torr and an N2 gas pressure of 0 Torr; cooling for 10 seconds between each pulse, with an N2 cooling pressure of 3 Torr; and a delay of 10 seconds between each pulse.
[0078] Preferably, a dilution pulse etching process includes the following steps:
[0079] Open gas flow meter 1, valves 1 and 5 open, and the remaining valves are closed. N2 and XeF2 gases enter the expansion chamber. When the gas pressure in the expansion chamber reaches the predetermined value (usually 5-10 Torr), valves 1 and 5 close.
[0080] Valves 2, 8, and 9 are opened, while the remaining valves are closed. Simultaneously, the timer starts. Since the XeF2 etching chamber is initially under vacuum, N2 and XeF2 gases diffuse from the expansion chamber into the etching chamber, chemically etching the wafer within. At the same time, the circulation pump starts operating, ensuring a more uniform and even distribution of gas within the expansion and XeF2 etching chambers, improving etching uniformity and gas utilization. When the pressure within the XeF2 etching chamber reaches a predetermined value (typically 1-5 Torr), valves 2 and 9 close; valve 8 remains open, while valve 10 opens, continuing gas flow within the etching chamber until the timer reaches the predetermined time value.
[0081] When valves two and three are opened and the remaining valves are closed, the XeF2 gas in the expansion chamber and the XeF2 etching chamber is pumped away by the first vacuum pump group until the vacuum in the XeF2 etching chamber reaches a predetermined value, usually <5e-5Torr.
[0082] Valves two and three are closed, valve four is open, and the remaining valves are closed. The XeF2 gas in the expansion chamber is pumped away by the vacuum pump until the vacuum in the expansion chamber reaches a predetermined value, at which point valve four is closed.
[0083] Steps 1)-4) above constitute a dilution pulse etching process. Typically, etching requires 1 to 100 pulse etching processes to complete wafer etching. It is also possible to pause between each pulse process (usually the pause time is 0-300 seconds) to reduce the substrate temperature. After all pulse processes are completed, if necessary, gas flow meter one can be turned on to introduce N2, and valves four and six can be opened to purge the expansion chamber. Valves three and seven can be opened to purge the etching chamber.
[0084] A typical process flow can be:
[0085] Cy10-etch30s-3TorrX-3TorrN-10sCool3TorrN-Delay10s;
[0086] That is, 10 pulse cycles: each pulse etches for 30 seconds, with an XeF2 gas pressure of 3 Torr and an N2 gas pressure of 3 Torr; cooling for 10 seconds between each pulse, with an N2 cooling pressure of 3 Torr; and a delay of 10 seconds between each pulse.
[0087] In practice, for MEMS devices, the method of depositing self-assembled monolayers (SAM) is usually adopted immediately after the etching is completed and the microstructure is released.
[0088] This invention employs a dry vapor phase SAM coating, which has major advantages over traditional wet chemical coatings. In particular, the vacuum deposition environment eliminates the problem of moisture variation, which is crucial for creating repeatable and robust surface coatings. At the same time, precise control of the equipment process can reduce the amount of chemicals used, provide excellent surface properties, and improve surface energy control.
[0089] The deposition chamber 503 is connected to the XeF2 etching chamber through the transport chamber, allowing the MEMS structure to be processed without disrupting the vacuum, thereby maximizing the yield.
[0090] The function of SAM depends on the chemical composition used. The head group can make the sample hydrophobic, bioactive, hydrophilic, or have a completely different function. The tail group, that is, the end that binds to the device surface, can also be selected according to the surface it binds to. It can be a chlorosilane group (SiCl3), which ultimately forms Si-Si bonds on the substrate and releases a very small amount of chlorine gas. This can typically bind to silicon, silicon oxide, and silicon nitride surfaces, as well as a range of metal surfaces. Another common group, thiols, reacts with gold surfaces via sulfur bonds.
[0091] The most commonly used SAM coating is:
[0092] FDTS: CF3(CF2)7(CH2)2SiCl3, perfluorodecyltrichlorosilane / perfluorodecyltrichlorosilane
[0093] OTS: CH3(CH2)17(CH2)2SiCl3, octadecyltrichlorosilane
[0094] FOTS: CF3(CF2)5(CH2)2SiCl3
[0095] FOTES: CF3(CF2)5(CH2)2Si(OC2H5)3
[0096] FOMDS: CF3(CF2)5(CH2)2Si(CH3)Cl2
[0097] FOMMS: CF3(CF2)5(CH2)2Si(CH3)2Cl
[0098] DDMS: Dichlorodimethylsilane
[0099] Most raw materials for SAM coatings are liquids at room temperature. For example, FDTS is a colorless liquid at room temperature with a density of 1.7 g / mol and a boiling point of 224°C at normal pressure.
[0100] In practical applications, liquid SAM raw materials are usually required to be converted into a gaseous state for thin film deposition. At the same time, the wafer substrate can also be heated, usually to 120°C, to enhance the reaction efficiency.
[0101] Preferred, such as Figure 3 As shown, Example 1 of the deposition of self-assembled monolayer module 5:
[0102] The self-assembled monolayer deposition module 5 further includes a carrier gas source, a first storage tank 501, a second storage tank 502, and a second vacuum pump group. The carrier gas source is connected to the deposition chamber 503 via pipeline eleven, which is equipped with valve eleven. The carrier gas source is connected to the first storage tank 501 and the second storage tank 502 via pipeline twelve, which is equipped with valve twelve and gas flow meter two between pipeline twelve and the first storage tank 501. It is equipped with valve thirteen and gas flow meter three between pipeline twelve and the second storage tank 502. The first storage tank 501 and the second storage tank 502 are connected to the deposition chamber 503 via pipeline thirteen. The deposition chamber 503 is connected to the transport chamber 2 and is connected to the second vacuum pump group via pipeline fourteen, which is equipped with valve fourteen. Both the first storage tank 501 and the second storage tank 502 are equipped with heating devices 504.
[0103] Specifically, the SAM material is deposited on the wafer using the bubble method, which includes the following methods:
[0104] Liquid SAM is sealed and stored in a first storage tank 501. The first storage tank 501 can be precisely heated to create a vapor pressure of SAM in the upper space of the first storage tank 501. Valve 12 is opened, and the carrier gas flow rate is precisely controlled by gas flow meter 2. The carrier gas is blown into the liquid SAM to further increase the vapor pressure of SAM in the upper space of the first storage tank 501. At the same time, gaseous SAM is blown into the deposition chamber 503 through pipeline 13. The carrier gas is usually Ar or N2. Pipeline 13 is also precisely heated to maintain a constant gas pressure. After the SAM gas enters the deposition chamber 503, it is precisely and uniformly deposited on the sample surface through the spray pipeline in the deposition chamber 503 to form a SAM coating.
[0105] Sometimes, two SAM materials, or other auxiliary deposition materials, are required. Then:
[0106] SAM-1 liquid raw material is sealed and stored in the first storage tank 501. The first storage tank 501 can be precisely heated to form the vapor pressure of SAM-1 raw material in the upper space of the first storage tank 501. SAM-2 or other auxiliary liquid raw materials are sealed and stored in the second storage tank 502. The second storage tank 502 can be precisely heated to form the vapor pressure of SAM-2 or other auxiliary raw materials in the upper space of the second storage tank 502. Valves 12 and 13 are opened, and the carrier gas flow rate is precisely controlled by gas flow meter 2 and gas flow meter 3 respectively. The carrier gas is blown into the liquid raw material to further increase the vapor pressure of the raw material in the upper space of the storage tank. At the same time, the gaseous material is blown into the deposition chamber 503 through pipe 13. The carrier gas is usually Ar or N2. Pipe 13 is also precisely heated to maintain a constant gas pressure. After the gas enters the deposition chamber 503, it is precisely and uniformly deposited on the sample surface through the spray pipe in the deposition chamber 503 to form a coating.
[0107] Preferred, such as Figure 4 As shown, Example 2 of the deposition of self-assembled monolayer module 5:
[0108] The self-assembled monolayer deposition module 5 further includes a carrier gas source, a steam generator, a first storage tank 501, a second storage tank 502, and a second vacuum pump group. The carrier gas source is connected to the evaporator via pipeline 15, and a gas flow meter 4 is installed on pipeline 15. The carrier gas source is connected to the first storage tank 501 and the second storage tank 502 via pipeline 16, and a gas flow meter 5 is installed between the carrier gas source and pipeline 16. Valves 15 and 16 are installed between the first storage tank 501, the second storage tank 502, and pipeline 16, respectively. The first storage tank 501 and the second storage tank 502 are connected to the evaporator via pipeline 17, and liquid flow meter 1 and liquid flow meter 2 are installed between the first storage tank 501, the second storage tank 502, and pipeline 17, respectively. The evaporator is connected to the deposition chamber 503 via pipeline 18. The deposition chamber 503 is connected to the transport chamber 2 and is connected to the second vacuum pump group via pipeline 19, and a valve 17 is installed on pipeline 19.
[0109] Specifically, SAM material is deposited on the wafer using a vaporization method, including the following methods:
[0110] SAM liquid raw material is sealed and stored in the first storage tank 501;
[0111] The carrier gas flow rate is precisely controlled by a gas flow meter and enters the steam generator;
[0112] At the same time, valve 15 is opened, and the carrier gas is precisely controlled by gas flow meter 5 and blown into the first storage tank 501. The gas pressure forces the liquid SAM raw material into pipeline 17, and the liquid flow is precisely controlled by liquid flow meter 1 and transmitted to the steam generator.
[0113] The steam generator vaporizes the SAM liquid and carries / blows the SAM gas into the deposition chamber 503 by a carrier gas, which is usually Ar or N2. After the SAM gas enters the deposition chamber 503, it is precisely and uniformly deposited on the sample surface through the spray pipes inside the deposition chamber 503 to form a SAM coating.
[0114] Sometimes, two SAM materials or other auxiliary deposition materials are required, which can be done as follows:
[0115] SAM-1 liquid raw material is sealed and stored in the first storage tank 501, while SAM-2 or other liquid raw materials are sealed and stored in the second storage tank 502.
[0116] The carrier gas flow rate is precisely controlled by a gas flow meter and enters the steam generator;
[0117] At the same time, valves 15 and 16 are opened, and the carrier gas is precisely controlled by gas flow meter 5 and blown into the first storage tank 501 and the second storage tank 502. The gas pressure forces the liquid raw material into pipeline 17, and the liquid flow is precisely controlled by liquid flow meter 1 and liquid flow meter 2 and transmitted to the steam generator.
[0118] The steam generator vaporizes the liquid raw material and carries / blows the raw material gas into the deposition chamber 503 by a carrier gas, which is usually Ar or N2. After the raw material gas enters the chamber, it is precisely and uniformly deposited on the sample surface through the spray pipes in the deposition chamber 503 to form a coating.
[0119] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.
Claims
1. An XeF2 etching apparatus, characterized in that, include: The loading chamber is used to load the workpiece or wafer that needs to be etched, and a first vacuum valve is provided between it and the outside world. The transport cavity is equipped with a robotic arm, which is connected to the loading cavity, the deposition self-assembly monolayer module, the plasma etching cavity, and the XeF2 etching process module. A second vacuum valve is provided between the transport cavity and the loading cavity, the deposition self-assembly monolayer module, the plasma etching cavity, and the XeF2 etching process module. A self-assembled monolayer module for deposition, comprising a deposition chamber, for SAM deposition on a workpiece or wafer; Plasma etching chamber, which is used to perform plasma etching on workpieces or wafers; The XeF2 etching process module includes an XeF2 etching chamber for XeF2 etching of workpieces or wafers.
2. The XeF2 etching apparatus according to claim 1, characterized in that: The XeF2 etching process module also includes an XeF2 gas source, an N2 gas source, an expansion chamber, a circulating pump, and a first vacuum pump group. The XeF2 gas source is connected to the expansion chamber via pipeline one, and pipeline one is equipped with valve one. The N2 gas source is connected to pipeline one, the expansion chamber, and the XeF2 etching chamber via pipeline two, and pipeline two is equipped with valve five, valve six, valve seven, and a gas flow meter one between pipeline one, the expansion chamber, the XeF2 etching chamber, and the N2 gas source. The expansion chamber is connected to the XeF2 gas source via pipeline three. The etching chamber is connected, and valve 2 is provided on pipe 3. The XeF2 etching chamber is connected to the transport chamber, and the XeF2 etching chamber is connected to the circulation pump and the first vacuum pump group through pipe 4 and pipe 5 respectively. Valve 8 is provided on pipe 4 and valve 3 is provided on pipe 5. The expansion chamber is connected to the first vacuum pump group through pipe 6, and valve 4 is provided on pipe 6. The circulation pump is connected to the expansion chamber and the XeF2 etching chamber through pipe 7 and pipe 8 respectively. Valve 9 is provided on pipe 7 and valve 10 is provided on pipe 8.
3. The XeF2 etching apparatus according to claim 1, characterized in that: The self-assembled monolayer deposition module further includes a carrier gas source, a first storage tank, a second storage tank, and a second vacuum pump assembly. The carrier gas source is connected to the deposition chamber via pipeline eleven, which is equipped with valve eleven. The carrier gas source is connected to the first and second storage tanks via pipeline twelve, which is equipped with valve twelve and gas flow meter two between pipeline twelve and the first storage tank. Pipeline twelve is equipped with valve thirteen and gas flow meter three between pipeline twelve and the second storage tank. The first and second storage tanks are connected to the deposition chamber via pipeline thirteen. The deposition chamber is connected to the transport chamber and to the second vacuum pump assembly via pipeline fourteen, which is equipped with valve fourteen. Both the first and second storage tanks are equipped with heating devices.
4. The XeF2 etching apparatus according to claim 1, characterized in that: The self-assembled monolayer deposition module further includes a carrier gas source, a steam generator, a first storage tank, a second storage tank, and a second vacuum pump assembly. The carrier gas source is connected to the evaporator via pipeline 15, and a gas flow meter 4 is installed on pipeline 15. The carrier gas source is connected to the first and second storage tanks via pipeline 16, and a gas flow meter 5 is installed between the carrier gas source and pipeline 16. Valves 15 and 16 are installed between the first and second storage tanks and pipeline 16, respectively. The first and second storage tanks are connected to the evaporator via pipeline 17, and liquid flow meters 1 and 2 are installed between the first and second storage tanks and pipeline 17, respectively. The evaporator is connected to the deposition chamber via pipeline 18. The deposition chamber is connected to the transport chamber and connected to the second vacuum pump assembly via pipeline 19, and a valve 17 is installed on pipeline 19.