Microvalve-based mass flow control chemical vapor reaction apparatus for semiconductor and pan-semiconductor, and semiconductor device

Abstract

The present invention relates to the technical field of semiconductor manufacturing, and provides a microvalve-based mass flow control chemical vapor reaction apparatus for a semiconductor and a pan-semiconductor, and a semiconductor device. The apparatus comprises: multiple nozzles, the nozzles being connected to multiple microvalves, wherein gases passing through the nozzles are controlled by means of the multiple microvalves, the gases flow to a substrate after passing through the nozzles to perform a semiconductor process, and the microvalves are configured to adjust the opening degrees thereof so as to adjust the flow rate of the gases passing through the nozzles. In the present invention, precise and adjustable mass flow control of openings can be performed, thereby greatly improving the deposition uniformity of CVD, PECVD, and ALD; and the sequential cycle time of an ALD process can be shortened, the gas residence time can be reduced, and the film-forming speed can be increased, thereby improving the production capacity of devices. In addition, a showerhead can also be applicable to processes such as plasma ashing, plasma surface treatment and plasma etching, thus providing a common available apparatus for chemical and plasma-based vacuum process reaction chambers.

Description

A chemical vapor reaction device and semiconductor equipment for semiconductors and pan-semiconductors based on microvalve mass flow control Technical Field

[0001] The present invention generally relates to the field of semiconductor manufacturing technology. Specifically, the present invention relates to a chemical vapor reaction device and semiconductor equipment for semiconductors and pan-semiconductors based on microvalve mass flow control. Background Art

[0002] FIG1 shows a schematic diagram of the structure of a showerhead reactor in the prior art. As shown in FIG1 , in a chemical vapor deposition (CVD) device, a showerhead reactor typically has a showerhead plane parallel to the substrate, and the showerhead is capable of distributing the reaction gas uniformly or according to specified requirements on the substrate. Since the substrate can be heated separately from the gas distributor and the chamber wall, only the surface of the substrate needs to be kept at the process temperature, so the showerhead reactor is typically a cold-wall reactor. This helps to minimize deposition on the chamber walls. A coolant can be provided to help control the temperature of the showerhead to prevent deposition reactions from occurring inside the showerhead and clogging the pores in the showerhead.

[0003] The hole configuration of the showerhead is important for ensuring deposition uniformity. Typically, showerheads with different hole densities are configured to accommodate different processes. These can be quickly disassembled and switched to the appropriate showerhead as needed. This can be achieved by adding baffles or changing the air inlet. Furthermore, plasma chemical vapor deposition (PECVD) equipment operating at high pressures (greater than a few Torr) requires small holes; otherwise, localized hollow cathode discharges may occur in the holes, leading to heating and erosion.

[0004] Single-wafer atomic layer deposition (ALD) equipment also typically uses showerheads. Because single-wafer ALD requires the rapid and precise injection of precursor, carrier, and purge gases in a timed sequence, showerheads require independent pipelines for the three different gases and a large number of fine nozzles at the showerhead outlet to ensure uniform and rapid mixing or purging of these gases with different functions.

[0005] Traditionally, gas distribution is usually achieved by configuring the fluid mechanics of the pipes passing through the showerhead. Since different showerhead outlets have different pipe lengths, bends, and flow resistances from the upstream valves, repeated experiments or finite element analysis are required to obtain the optimal configuration. For ALD, since the flow rate switches at high speed according to a time sequence, it is a non-steady-state calculation process with a massive grid, and the difficulty or amount of calculation required to find the optimal solution increases exponentially. In addition, the control of gas flow in semiconductor equipment always requires the control of mass flow. The mass flow meter of the showerhead is located upstream of the showerhead, and it is not possible to achieve precise and adjustable mass flow control for each showerhead opening or a group of showerhead openings at each nozzle of the showerhead.

[0006] Sprinkler Injector Sprinkler Unit Injector Sprinkler Unit Summary of the Invention

[0007] To at least partially solve the above-mentioned problems in the prior art, the present invention provides a chemical vapor reaction device for semiconductors and pan-semiconductors based on microvalve mass flow control. The chemical vapor reaction device comprises:

[0008] A plurality of nozzles are connected to a plurality of microvalves, wherein the gas passing through the nozzles is controlled by the plurality of microvalves, and the gas flows to the substrate after passing through the nozzles to perform semiconductor processing, wherein the microvalves are configured to adjust their openings to adjust the flow rate of the gas passing through the nozzles.

[0009] In one embodiment of the present invention, it is provided that the microvalve comprises a proportional control valve, and the proportional control valve comprises a diaphragm valve.

[0010] In one embodiment of the present invention, the microvalve is connected to a pressure sensor and a temperature sensor, wherein the microvalve is configured to perform mass flow control on the gas passing through the nozzle based on a pressure flow control rate.

[0011] In one embodiment of the present invention, the microvalve includes a heater, a laminar flow element, a pressure sensor, and a temperature sensor, wherein the microvalve is configured to control the mass flow of the gas passing through the nozzle based on a temperature flow control rate.

[0012] In one embodiment of the present invention, it is provided that a plurality of microvalves are closely arranged on a plane; and / or

[0013] A plurality of nozzles are arranged below a plane where the microvalves are arranged, wherein the plurality of nozzles are closely arranged so that the gas passing through the nozzles covers the substrate to be processed.

[0014] In one embodiment of the present invention, a plurality of gases are configured to be mixed after passing through the nozzle and then flow toward the substrate to be processed.

[0015] In one embodiment of the present invention, it is provided that the nozzles for passing different types of gases are closely arranged in an interlaced manner.

[0016] In one embodiment of the present invention, it is provided that at least two of the multiple gases share a same microvalve.

[0017] In one embodiment of the present invention, the chemical vapor reaction device includes a plurality of shower head units closely arranged on a plane, wherein the upper portion of the shower head unit is connected to a micro valve, and the lower portion of the shower head unit is provided with a nozzle.

[0018] In one embodiment of the present invention, the shower head unit is in the shape of a polygon, a sector, or an arc segment.

[0019] In one embodiment of the present invention, it is stipulated that the semiconductor process includes chemical vapor deposition (CVD), plasma chemical vapor deposition (PECVD), atomic layer deposition (ALD), plasma atomic layer deposition (PEALD), plasma ashing (Plasma Ashing), photolithography (Light Etch), chemically assisted plasma etching (Chemical Assisted Plasma Etch) and plasma etching (Plasma Etch).

[0020] In one embodiment of the present invention, the outer diameter of the microvalve is less than or equal to 1.125 inches; and / or

[0021] The number of the valves is greater than or equal to 7.

[0022] In one embodiment of the present invention, the chemical vapor reaction device further comprises:

[0023] A plasma source is disposed between the microvalve and the substrate.

[0024] In one embodiment of the present invention, the plasma source comprises an inductively coupled plasma (ICP), a capacitively coupled plasma (CCP), a microwave device and a hollow cathode; and / or

[0025] The plasma source includes a micro plasma source or a plasma source micro array, wherein the plasma source micro array includes a micro discharge structure.

[0026] In one embodiment of the present invention, it is provided that the cavity of the micro-discharge structure serves as a gas flow channel of the shower head unit.

[0027] In one embodiment of the present invention, it is provided that the micro-discharge structure is arranged in a gas flow channel through which a plasma-insensitive gas passes.

[0028] In one embodiment of the present invention, a plurality of nozzles are arranged above the substrate, and the gas flows toward the substrate in a direction perpendicular to the plane of the substrate; or

[0029] A plurality of nozzles are arranged on the side of the substrate, and the gas flows toward the substrate in a direction parallel to the substrate plane.

[0030] In one embodiment of the present invention, it is provided that the gas pipeline without the function of uniform gas distribution or plasma chamber is constructed so that the microvalve is as close as possible to the substrate to eliminate the dead volume.

[0031] In order to ensure the accuracy of mass flow control to the surface of the substrate, an extremely important design criterion is to minimize the residual gas in the shower head. In the present invention, the physical control node of the mass flow is each microvalve, so the volume of the total pipeline from the microvalve to the outlet of the shower head is minimized, and the absence of dead corners in fluid flow is an extremely important design principle. For example, the plasma source chamber is directly implanted in each shower head unit and is integrated with the uniform gas pipeline of the shower head unit. After the microvalve, there are no pipelines that have the function of uniform gas distribution or plasma chamber but are simply used to transport gas. The microvalve should be moved further to the substrate side by optimizing the spatial layout to eliminate the invalid volume (residual gas volume).

[0032] The present invention further provides a semiconductor device, comprising:

[0033] a shower head, which is arranged above the substrate, the shower head being the chemical vapor reaction device, and performing diffuse purge on the top of the substrate; and

[0034] A horizontal injection valve is arranged on the side of the substrate, and the horizontal injection valve is configured to inject laminar flow to enable the substrate to undergo epitaxial growth, wherein the epitaxial growth includes etching and cyclic etching epitaxy, wherein silicon, silicon carbide, gallium nitride, and gallium oxide are epitaxially grown, wherein the shower head and / or the horizontal injection valve is provided with a plasma source microarray.

[0035] In one embodiment of the present invention, the plasma source microarray is configured to perform zone control so that different zones of a plane obtain different plasma power densities.

[0036] In one embodiment of the present invention, it is provided that the plasma source microarray has a bias voltage device, and the bias voltage device includes an AC bias or a DC bias.

[0037] The present invention further provides a semiconductor device, comprising:

[0038] a plurality of microvalves configured to control the flow of gas to the substrate; and

[0039] a plasma source disposed between the microvalve and the substrate;

[0040] The plasma source includes inductively coupled plasma, capacitively coupled plasma, microwave plasma, hollow cathode, dielectric barrier discharge structure; and / or

[0041] The plasma source includes a micro plasma source or a plasma source micro array, wherein the plasma source micro array includes a micro discharge structure, a dielectric barrier discharge structure or a hollow cathode.

[0042] The present invention has at least the following beneficial effects: It proposes a showerhead for semiconductor equipment that enables precise and adjustable mass flow control of the openings, thereby significantly improving deposition uniformity in CVD, PECVD, and ALD processes. Furthermore, it shortens the ALD process cycle time, reduces gas retention, and increases film formation speed, thereby increasing equipment productivity. The showerhead is also applicable to processes such as plasma ashing, plasma surface treatment, and plasma etching, providing a common, usable device for both chemical and plasma-based vacuum process chambers. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] To further illustrate the advantages and features of various embodiments of the present invention, a more detailed description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings depict only typical embodiments of the present invention and are not to be considered as limiting the scope of the present invention. In the drawings, for clarity, identical or corresponding components will be represented by the same or similar reference numerals.

[0044] FIG1 shows a schematic structural diagram of a shower head reactor in the prior art.

[0045] FIG2 shows a schematic structural diagram of a diaphragm valve in an embodiment of the present invention.

[0046] FIG3 shows a schematic diagram of the arrangement of the shower head units in one embodiment of the present invention.

[0047] FIG4 is a schematic structural diagram of a semiconductor device according to an embodiment of the present invention.

[0048] FIG5 shows a schematic structural diagram of a shower head unit in an embodiment of the present invention.

[0049] 6A and 6B are schematic diagrams showing the connection arrangement of a shower head unit in one embodiment of the present invention.

[0050] FIG. 7A shows a piping topology diagram of a showerhead unit having at least one valve according to an embodiment of the present invention.

[0051] FIG. 7B shows a piping topology diagram of a showerhead unit having three valves according to an embodiment of the present invention.

[0052] FIG8 shows a schematic diagram of the gas pipeline topology of a microvalve-based shower head according to an embodiment of the present invention.

[0053] FIG9 shows a schematic diagram of gas inlet and outlet at a valve in one embodiment of the present invention.

[0054] FIG10 is a schematic diagram showing changes in pressure and flow rate of a blocked flow in one embodiment of the present invention.

[0055] Figure 11 shows a schematic diagram of a mass flow control device with a variable porosity. Figure 12 shows a schematic diagram of the piping topology of a shower head based on a microvalve in one embodiment of the present invention.

[0056] FIG13 is a schematic diagram showing a pipeline topology of a shower head having multiple groups of shower head units according to an embodiment of the present invention.

[0057] 14A-C are schematic structural diagrams showing a group of showerhead units according to an embodiment of the present invention.

[0058] 15A-C are schematic diagrams showing the layout of multiple groups of showerhead units according to one embodiment of the present invention.

[0059] FIG. 16A is a schematic structural diagram of a reactor in which a plasma source is arranged above a shower head in one embodiment of the present invention.

[0060] FIG. 16B shows a schematic structural diagram of a reactor in which a plasma source is arranged inside a shower head in one embodiment of the present invention.

[0061] FIG17A shows a schematic diagram of a structure with a hollow cathode cavity.

[0062] FIG. 17B shows a schematic diagram of the piping topology of a shower head having a hollow cathode plasma source according to an embodiment of the present invention.

[0063] FIG. 18 shows a schematic structural diagram of a microvalve showerhead with a dielectric barrier microarray ion source according to an embodiment of the present invention.

[0064] FIG19 shows a schematic diagram of the pipeline topology of a microvalve showerhead with a dielectric barrier microarray ion source.

[0065] 20A-C are schematic diagrams showing group control of plasma sources of a microarray according to one embodiment of the present invention.

[0066] FIG21 shows a chemical vapor deposition system using microvalves. DETAILED DESCRIPTION

[0067] It should be noted that the components in the drawings may be shown exaggeratedly for the sake of illustration and are not necessarily correct to scale. In the drawings, identical or functionally identical components are provided with the same reference numerals.

[0068] In the present invention, unless otherwise specified, the phrases "disposed on," "disposed above," and "disposed above" do not exclude the presence of intermediate components. Furthermore, "disposed on or above" merely indicates the relative positional relationship between two components and, in certain circumstances, such as after reversing the product orientation, can be converted to "disposed below or below," and vice versa.

[0069] In the present invention, each embodiment is only intended to illustrate the aspects of the present invention and should not be construed as limiting.

[0070] In the present invention, unless otherwise specified, the quantifiers "a" and "an" do not exclude the presence of multiple elements.

[0071] It should also be noted that in the embodiments of the present invention, for the sake of clarity and simplicity, only a portion of the parts or components may be shown, but those skilled in the art will understand that, under the teachings of the present invention, the required parts or components can be added according to the needs of the specific scenario. In addition, unless otherwise stated, the features of different embodiments of the present invention can be combined with each other. For example, a feature in the second embodiment can be used to replace a corresponding or functionally identical or similar feature in the first embodiment, and the resulting embodiment also falls within the scope of disclosure or description of this application.

[0072] It should also be noted that, within the scope of the present invention, terms such as "same," "equal," and "equal to" do not imply absolute equality of values, but rather allow for a certain reasonable error. In other words, such terms also encompass "substantially the same," "substantially equal," and "substantially equal." Similarly, in the present invention, terms such as "perpendicular to" and "parallel to" indicating direction also encompass the meaning of "substantially perpendicular to" and "substantially parallel to."

[0073] In addition, the numbering of the steps of the methods of the present invention does not limit the order in which the steps are to be performed. Unless otherwise specified, the steps of the methods may be performed in different orders.

[0074] The present invention will be further described below with reference to the accompanying drawings in conjunction with specific embodiments.

[0075] When the present invention is used for single-wafer cyclic CVD based on microvalve, it has the following advantages: (1) It realizes precise control of each unit and the whole or region. (2) The gas stroke is short, shortening the cycle time. (3) High Tput, more cycles at the same time. (4) It has digital process adjustability. (5) Each valve is a mass flow control, precise process control. (6) There is no residual gas between the nozzle and the mass flow control valve (after the mass flow control stops working, the gas from the mass flow control valve outlet to the nozzle outlet can be regarded as residual gas in the ALD process because it has been separated from the measurement and control of the mass flow meter but has not yet entered the reaction chamber. Its existence interferes with the precise injection of the next gas flow). The control valve is placed in front of the nozzle outlet to minimize the existence of this section of gas. (7) For traditional mass flow control, the residual gas volume reaches the milliliter level and cannot achieve a sccm level of mass flow control. The present invention can achieve precise mass flow control at the sccm level at the nozzle outlet. (8) It can use a flow compensation algorithm. (9) No need to replace the gas distribution plate, the uniformity can be set digitally.

[0076] Figure 2 shows a schematic structural diagram of a diaphragm valve in one embodiment of the present invention. The diaphragm valve can be used in the chemical vapor reaction device proposed in the present invention.

[0077] The present invention can utilize Horiba's slim DZ100 mass flow controller, which has a lateral width of less than 10 mm. That is, the outer diameter (OD) of its mini Piezo valve is less than 10 mm. This allows for a maximum close-packing of approximately 30 valves along a 300 mm diameter substrate.

[0078] FIG3 shows a schematic diagram of the arrangement of the showerhead units in one embodiment of the present invention. A showerhead unit (honeycomb) with a diagonal of 40 mm can achieve dense tiling on a plane. This results in 8-9 honeycombs on the diameter. A honeycomb with a diagonal of 30 mm (1.125 inches) can achieve dense tiling on a plane. This results in 10-11 honeycombs on the diameter. A honeycomb with a diagonal of 20 mm can achieve dense tiling on a plane. This results in 16-17 honeycombs on the diameter. A honeycomb with a diagonal of 10 mm can achieve dense tiling on a plane. This results in 30-31 honeycombs on the diameter.

[0079] 4 shows a schematic structural diagram of a semiconductor device according to an embodiment of the present invention. The semiconductor device includes a chemical vapor reaction device according to the present invention.

[0080] FIG5 is a schematic diagram showing the structure of a shower head unit in one embodiment of the present invention. FIG6A and FIG6B are schematic diagrams showing the connection arrangement of a shower head unit in one embodiment of the present invention. The shower head unit (honeycomb) composed of the airflow control valve and the air uniformity mechanism can achieve hexagonal plane tiling. Quadrilaterals or triangles can also form tiling. Hexagons are closer to circles and are a better choice for semiconductor wafer equipment. Solar energy equipment can preferably choose quadrilaterals to complete tiling (photovoltaic substrates are quadrilaterals). The fine gas outlet structure on the bottom surface achieves the maximum gas distribution effect.

[0081] Figure 7A shows the piping topology of a showerhead unit with at least one valve in one embodiment of the present invention. Figure 7B shows the piping topology of a showerhead unit with three valves in one embodiment of the present invention. As shown in Figures 7A and 7B, fine nozzles for two or more independent gases are interlaced and densely distributed to achieve sufficient mixing of the gases before reaching the substrate.

[0082] FIG8 shows a schematic diagram of the gas pipeline topology of a microvalve-based shower head in one embodiment of the present invention. There is only one valve for each of the three gas groups. Multiple valves for the same group (precursor gas) of gases have a common temperature and pressure measurement strategy. The outlet flow of the valve (valve) is proportional to Pup (blocked flow) or proportional to Pup. 2 -Pdown 2 Therefore, the mass flow rate of each valve can be precisely controlled through fluid mechanics, or the mass flow rate of the gas at each valve outlet can be proportionally distributed from another angle.

[0083] Auxiliary gases (carrier and purge gases) may not need to have their own microvalves in the injector showerhead unit. Gas distribution can be done by mass flow control in the upstream manifold according to the traditional pipeline strategy.

[0084] A microvalve-based showerhead consists of multiple showerhead units equipped with microvalves. Each injector showerhead unit contains one or more proportional control valves (desirably, the valves are small enough to allow for sufficient number, so smaller valves or even microvalves are preferred) and densely distributed nozzles. Each injector showerhead unit can have multiple independent gas outlets, such as precursors, reaction gases, etching gases, carrier gases, and / or purge gases. The valves are preferably diaphragm valves or other proportional valves.

[0085] Multiple valves for the same group of gases have a common temperature and pressure measurement strategy. The outlet flow of the valve is proportional to Pup (blocked flow) or Pup- 2 Pdown 2Therefore, the mass flow rate of each valve can be precisely controlled through fluid mechanics, or the mass flow rate of the gas at each valve outlet can be proportionally distributed from another angle.

[0086] The assist gas may not require its own microvalve in the injector showerhead unit, but rather be distributed using a traditional pipeline strategy with mass flow control in the upstream manifold.

[0087] The blocking flow and non-blocking flow are explained below.

[0088] Blockage occurs when the flow velocity at a certain section of a pipe reaches the speed of sound. Regardless of how much the pressure outside the pipe outlet decreases, the velocity and pressure of the airflow before the sonic section remain unchanged, and the flow rate remains constant. Blockage is prone to occur in a variety of situations, including starting blockage in supersonic wind tunnels (see wind tunnel), aircraft inlet blockage, friction tube blockage, and heating tube blockage.

[0089] Taking the blockage in the aircraft inlet as an example, when the airflow Mach number is far ahead of the inlet, 00 When the Mach number at the throat is less than 1, the airflow velocity in front of the inlet increases, the velocity at the throat increases, and the flow rate increases. 00 = 1, even if the airflow velocity in front of the inlet increases, the flow rate will no longer increase, only supersonic flow and shock wave will appear after the throat; when the Mach number of the airflow far ahead is Ma 00 When the ratio is greater than 1, the supersonic airflow flows directly into the inlet without any disturbance before the inlet. When the throat area is large enough to allow all incoming gas to pass through, the inlet is unobstructed. When the throat area is too small, and the flow rate that can pass is less than the flow rate that would enter directly, the throat becomes blocked, gas accumulates before the throat, and the pressure rises, forming a shock wave before the inlet. Some excess airflow overflows the outlet, resulting in a supersonic region and shock wave after the throat. Blockage in an aircraft's inlet significantly increases the aircraft's drag and significantly reduces the engine's thrust.

[0090] Figure 9 shows a schematic diagram of the inlet and outlet of a valve in one embodiment of the present invention. As shown in Figure 9, for a compressible fluid, if the pressure P1 at the valve's inlet remains constant and the pressure P2 at the outlet gradually decreases, the mass flow rate through the valve will gradually increase to a maximum value. At this point, further reducing P2 will no longer increase the flow rate. This situation is called choked flow. To form a choked flow, it is usually necessary to make P1 ≥ 2P2 (the specific ratio is related to the specific heat capacity of the gas). At this time, the flow rate through the valve is only related to P1 and is proportional to the absolute value of P1.

[0091] FIG10 shows a schematic diagram of the change of pressure and flow rate of a blocked flow in one embodiment of the present invention. The blocking point of the fluid is determined by the pressure recovery factor F of the liquid.L And the critical pressure difference ratio coefficient X of the gas without an attached tube T The liquid forms vapor and the gas reaches the speed of sound at the contraction neck. The critical pressure value can be calculated by the following formula: F F =0.96-0.28(P V / P C ) 1 / 2

[0092] Among them, F F Indicates the liquid critical pressure ratio factor, P V represents the fluid vapor pressure, P C represents the thermodynamic critical pressure.

[0093] Blockage critical pressure P at the valve choked The ratio between P1 and P2 can be expressed as follows:

[0094] Where n represents the exponent of isentropic expansion / compression. For ideal gases in a thermal system, n is the ratio of specific heats: n = Cp / C v , where C p Indicates specific heat at constant pressure, C v It represents the specific heat at constant volume. For most process steams operating in the wet zone, n = 1.135, for superheated steam n = 1.30, for air n = 1.4, for methane n = 1.31, and for helium n = 1.667.

[0095] For air, the calculation of the critical pressure ratio can be expressed as:

[0096] The corresponding relationships between n and the critical pressure ratio of other gases may be 1.1135, 0.577; 1.300, 0.546; 1.400, 0.528; 1.667, 0.487.

[0097] The mass flow rate of the choked flow through the valve, that is, the sonic flow with the minimum pressure equal to the critical pressure, can be expressed as follows:

[0098] Among them, m c Indicates the mass flow rate of sonic flow (kg / s), A c Indicates the nozzle area (m 2 ), ρ1 represents the density of the valve inlet (kg / m 3 ).

[0099] For non-blocked flow, the pressure function upstream and downstream of the valve is The secondary flow rate can be determined by the following formula: Q = k × Function (P UP , P DOWN ).

[0100] At the valve of non-blocking flow, the flow rate Specifically, it can be expressed as the following formula:

[0101] According to the above formula, in P UP 、P DOWN Under the same conditions, the flow rate Q at the valve of non-blocking flow is i The opening area A is proportional to the non-blocked flow. In the present invention, the opening area A can be adjusted by an electrical control circuit and controlled by a control unit.

[0102] The mass flow control method of the microvalve-based shower head proposed in the present invention is similar to the mass flow control method controlled by a mass flow regulating device with a variable porosity. FIG11 shows a schematic diagram of a mass flow regulating device with a variable porosity. The mass flow control principle thereof will be described below in conjunction with FIG11. As shown in FIG11, the device includes: a variable porosity LFE or valve, so that the opening area A(x) is a function of an input electrical signal; pressure sensors located upstream and downstream of the opening; a temperature sensor T; the opening area A(x) is controlled by the input signal to obtain a specified mass flow rate; the mass flow rate is a function of Pup, Pdown, A, and T, and obeys the respective fluid mechanics according to blocked flow and non-blocked flow.

[0103] The V00 mass flow control device includes: the upstream of multiple valves is connected to a pressure distribution vessel (PDV); the pressure sensors upstream and downstream of the multiple valves measure a pressure drop of ΔP i = Pupstream i - Ppdv generated by the flow from Ppdv to valve i, and the pressure drop satisfies the continuity relationship of the fluid; for each proportional flow demand, the opening ratio Ai that meets the requirement is calculated to obtain the specified Qi at Oi (the Pup i at valve i determines the flow of Qi to Pchamber and the opening area Ai. That is, the flow is a data set based on (Ppdv, ΔP i, Pchamber, Ai). Through the relationship between fluid mechanics flow and differential pressure, and through actual calibration data Qi (Ppdv, ΔP i, Pchamber, Ai).

[0104] Multiple mass flow controllers located upstream of the PDV provide the mass flow rates of multiple reactant gases and mix them to provide a total gas volume that needs to be proportionally distributed. Downstream systems distribute the output to multiple ports according to the specified mass percentages.

[0105] There is a mass flow meter for gas upstream of the PDV. The downstream pressure equalizing vessel PDV can be a pipe, a preset channel in the injector, a sprinkler, etc. The vessel should be designed as reasonably as possible in the available physical space (reduce bends, the inlet is located in the center of each outlet, and the largest container inner diameter is used when possible) so that the pressure of each valve located downstream or at its outlet is similar. The pressure regulating valve located at the upstream inlet of the pressure equalizing vessel PDV allows the vessel to obtain a given pressure P pdv. The pressure gauge PT upstream and the temperature gauge of the equalizing vessel PDV are used to measure P upstream or P pdv (P upstream or P pdv can be the one closest to the inlet P up i).

[0106] When the pressure equalization vessel is ineffective (e.g., a vessel that is too long or too thin, causing a significant pressure drop, or a large difference in downstream valve opening size, causing a significant local pressure drop), it is necessary to configure PT up1 through PT up n at each outlet (upstream of n valves) to obtain the accurate pressure upstream of the valve. ΔPi = P up iP pdv.

[0107] n valves located at the outlet of the pressure-equalizing vessel. These valves are variable-opening valves, meaning their openings can be automatically adjusted. These variable valves can be laminar flow elements (LFEs). n pressure transducers (PTs) located downstream of the N valves.

[0108] There are two situations where the downstream pressure gauge can be combined or the pressure gauge output value P chamber of the chamber itself can be used instead: when the flow is blocked, the flow rate is insensitive to the downstream (P up > 2*P down); when the downstream reaction chamber is large, the pressure gradient at each outlet is small and P down is similar.

[0109] The reaction chamber is pressure-measured using a PT chamber. A downstream vacuum pump or exhaust system evacuates the chamber. The pressure control valve (PCV) between the chamber and the pump is adjusted to maintain the desired pressure. The pressure gauge, mass flow control, and mass flow meter are controlled by the same controller.

[0110] The device can be a standalone controller similar to a mass flow controller. It is connected to the chamber via a pipe. The device is integrated with an injector. Specifically, the injector has n nozzles, each with a V00 and Pup sensor. The PDV is connected to the V00 and Pup sensors within the injector via a pipe or VCR connector.

[0111] Figure 12 shows a schematic diagram of the piping topology of a microvalve-based shower head according to one embodiment of the present invention. As shown in Figure 12, the mass flow control method of each injector shower head unit is as follows:

[0112] Multiple valves for the same group (precursor gas) of gases have a common temperature and pressure measurement strategy. The outlet flow of the valve is proportional to Pup (blocked flow) or proportional to Pup 2 -Pdown 2 Therefore, the mass flow rate of each valve can be precisely controlled through fluid mechanics, or the mass flow rate of the gas at each valve outlet can be proportionally distributed from another angle.

[0113] Auxiliary gases (carrier and purge gases) may not need to have their own microvalves in the injector showerhead unit. Gas distribution can be done by mass flow control in the upstream manifold according to the traditional pipeline strategy.

[0114] Pressure sensors P are added upstream and downstream of the outlet of each microvalve, so that the mass flow rate at the outlet of each microvalve can be accurately controlled by the flow control method of the sprinkler head.

[0115] In multiple independent gas systems, the second and / or third gases share a common microvalve compared to the first and / or second gases, reducing the number of microvalves. In many processes, two or more process gases need to be mixed. This is particularly true for deposition processes like CVD and ALD, where premature mixing of two gases is undesirable due to concerns about condensation or premature deposition. Therefore, within a single showerhead unit, it is desirable to precisely control the mass flow of the second gas.

[0116] In one embodiment of the present invention, a showerhead unit has two or more valves to achieve mass flow control for two or more gas lines. In this embodiment, a single showerhead unit requires two or more control valves, making the unit too bulky (using the aforementioned valves, the OD of a single showerhead unit is nearly 20 mm). Therefore, further optimization is being considered.

[0117] Figure 13 shows a schematic diagram of the piping topology of a showerhead with multiple showerhead units, according to one embodiment of the present invention. As shown in Figure 13, in a preferred embodiment of the present invention, several showerhead units are grouped to form rings, zones, and groups. Each showerhead unit has at least one control valve corresponding to one reactant gas path, providing mass flow control for that gas path.

[0118] Another gas path or multiple gas paths of a group of showerhead units have an upper mass flow control valve. This control valve also implements precise mass flow control of the total amount of gas in this path based on the aforementioned flow control principle.

[0119] Below the valve, the pipelines of each sprinkler head unit are optimized, such as being symmetrical in all directions, so that the flow resistance of each flow channel is equal, thereby achieving equal flow distribution between each sprinkler head unit under the mass flow control valve.

[0120] The same gas in several rings / zones / groups is connected to the mass flow controller (or mass flow meter) of the gas box. These several rings / zones / groups of showerhead units realize the dense paving of the substrate plane.

[0121] Figures 14A-C illustrate the structure of a group of showerhead units in one embodiment of the present invention. As shown in Figures 14A-C, the showerhead units are hexagonal in shape. Seven hexagonal showerhead units form a zone, with each showerhead unit controlling the mass flow of a first gas, typically a precursor. The second and third gases of the seven showerhead units share a common upper-level control valve, which controls the total mass flow of the seven showerhead units.

[0122] In multiple independent gas channels, the second and / or third gases use a common microvalve compared to the first and / or second gases, reducing the number of microvalves. Seven valves for the first gas and the valves shared by the second and third gases form a control unit.

[0123] Figures 15A-C show a schematic layout diagram of multiple groups of shower head units in one embodiment of the present invention. Each injector shower head unit has 7 control valves for the first gas, and each valve can independently and accurately control the mass flow rate of the first gas, with a total of 7 control points. Each injector shower head unit has two control valves for the second gas and the third gas, which accurately control the mass flow rate of the second gas and the third gas respectively. There are a total of ring 1 + ring 2 + ring 3, a total of 1+6+12=19 injector shower head units. There are 133 mass flow control points for the first gas, 19 mass flow control points for the second gas and 19 mass flow control points for the third gas, a total of 171 microvalves. By setting up multiple microvalves, the flexibility of process control can be far greater than that of the existing technology, the distance from the valve to the inject outlet can be greatly shortened, and the capacity of the residual gas is also significantly reduced.

[0124] Using nine-valve hexagonal showerhead units to achieve planar tiling allows for modularization of the showerhead unit, significantly reducing the number of different components. The disadvantage is that the resulting tiling results in a jagged hexagonal shape. Squares and equilateral triangles can also be used for tiling. Instead of pursuing polygonal planar tiling, more complex topologies or less symmetrical plane divisions can be used, such as sector-based showerhead unit organization. Each cell injector is located at a different angular orientation on a different ring, making this a better choice for circular semiconductor wafers from a process perspective.

[0125] Figure 16A shows a schematic diagram of a reactor structure in which a plasma source is positioned above a showerhead, according to one embodiment of the present invention. As shown in Figure 16A , for a microvalve structure, a corresponding small plasma source is required to ensure that each microvalve or showerhead unit has a corresponding independent plasma source. One approach is to use a traditional plasma source, such as a miniaturized toroidal ICP, a small parallel-plate CCP plasma source, or a small microwave plasma source. Generally speaking, plasma-activated gases have a significant ablative and even disruptive effect on microvalves, necessitating their placement behind the valves. Larger traditional plasma sources (ranging from tens to several centimeters) are often difficult to embed within the showerhead and must be conventionally positioned externally. Plasma sources that are too far away can lead to extensive plasma recombination and annihilation. Another approach is to use a microplasma source, such as a microdischarge. This allows each microvalve or showerhead unit to become an independent plasma, resulting in a highly uniform surface plasma source.

[0126] FIG16B shows a schematic diagram of the structure of a reactor in which a plasma source is arranged inside a showerhead in one embodiment of the present invention. As shown in FIG16B , a small parallel plate (capacitively coupled plasma (CCP)) plasma source is embedded in the showerhead, and Gas 1 enters the reaction chamber through an opening below under mass flow control. Gas 2 and Gas 3 have multiple microvalves, and the mass flow gas controlled by each microvalve enters the gas distribution structure below through its own pipeline passing through the CCP plasma source cavity, and is distributed to more shower outlets through branch pipes. After the showerhead outlet, Gas 1 and Gas 2 & 3 complete the convergence to perform the process on the substrate below.

[0127] FIG17A shows a schematic diagram of a structure with a hollow cathode cavity. As shown in FIG17A , the typical diameter D of a hollow cathode tube is about several mm to several cm. The inner diameter of a 1 / 8-inch metal pipe commonly used in semiconductors is about 2.1 mm, and the diameter of a shower head unit is about 20 mm, which is sufficient to serve as a discharge cavity for a small hollow cathode plasma source. FIG17B shows a schematic diagram of the piping topology of a shower head with a hollow cathode plasma source in one embodiment of the present invention. As shown in FIG17B , the diameter of the hollow cathode cavity is 6 mm. At the outlet of the shower head, the nozzle diameter can be controlled to a sub-millimeter diameter of about 0.1-0.5 mm, so that parasitic hollow cathode discharge does not occur at the nozzle outlet.

[0128] In addition to using traditional plasma sources, such as miniaturized spiral tube ICP, small flat CCP or traditional hollow cathode plasma source, another way is to use micro plasma source, such as micro discharge. In this way, each micro valve or shower head unit can become an independent plasma, thus obtaining a very uniform surface plasma source.

[0129] Figure 18 shows a schematic diagram of the structure of a microvalve showerhead with a dielectric barrier microarray ion source, according to one embodiment of the present invention. As shown in Figure 18 , an electrode microarray is located beneath the channel, with a dielectric material separating the positive and negative electrodes in the microarray. The gaps between the electrode microarrays allow plasma to pass through.

[0130] Microdischarge, with its low power and high density, has long been considered a promising method for generating stable DC non-thermal plasmas at relatively high pressures. Depending on the electrode structure used to generate the microdischarge, it can be categorized as micro-dielectric barrier discharge, micro-corona discharge, capillary discharge, jet discharge, and micro-hollow cathode discharge. Micro-hollow cathode discharge is a common microdischarge method that reduces the cavity size to millimeter or even submillimeter scales based on the hollow cathode discharge structure. Compared to other discharge methods, hollow cathode discharge possesses a unique discharge characteristic known as the hollow cathode effect, enabling higher charged particle densities at the same pressure. Hollow cathode discharge also boasts a wide pressure range, capable of generating stable plasmas from high vacuum to atmospheric pressure. This allows it to cover the entire semiconductor process pressure range, from vacuum to reduced pressure to atmospheric pressure.

[0131] The inner diameter of a 1 / 8-inch metal pipe commonly used in semiconductors is approximately 2.1 mm. The inner diameter of the millimeter and submillimeter micro-discharge cavity in the present invention exactly matches the inner diameter of the pipe of the injector showerhead unit. Therefore, the gas pipeline in the injector can be directly used as the cavity for micro-discharge. In terms of topological structure, different gases have different connection layers. In particular, in the topmost Gas1 connection layer, there are no large number of Gas2 and Gas3 pipes in this plane, which can achieve selective excitation of only the Gas1-excited plasma, thereby avoiding the premature occurrence of deposition or decomposition reactions inside the showerhead unit.

[0132] Figure 19 shows a schematic diagram of the pipeline topology of a microvalve showerhead with a dielectric barrier microarray ion source. As shown in Figure 19 , the dielectric discharge cavity ends at a dielectric barrier plate. Electrodes are placed on both sides of the dielectric barrier plate, forming a dielectric barrier discharge (DBD) structure. A dielectric capillary (capillary or residual gas source) or nozzle is located in the center of the dielectric barrier plate. The inner diameter of the capillary is approximately 0.2 mm. The capillaries are connected to the showerhead outlet one by one. The inner diameter of the plasma source cavity ranges from 1 to 30 mm and can be embedded within the interior of the aforementioned single showerhead unit. That is, each microvalve has a corresponding independent plasma source cavity. Therefore, for example, the 133 mass flow control points described in the aforementioned embodiment can each have an independent plasma source distributed across the entire 300 mm substrate surface. Ideally, these 133 plasmas can be equipped with 133 independent power supplies, enabling independent control of each plasma source. Alternatively, the valve modules can be grouped, such as in the aforementioned embodiment, each controlled by an independent plasma power supply, for a total of 19 independent plasma power supplies for zoned control. Compared with the device shown in FIG18 , the plasma source chamber selectively plasmatizes only gas2, and Gas1 and Gas3 merge with the plasma of Gas2 after leaving the shower head, thereby reducing parasitic effects such as deposition and decomposition that may occur when Gas1, Gas2, and Gas3 are in the plasma state together.

[0133] Figures 20A-C show a schematic diagram of group control of the plasma sources of a microarray in one embodiment of the present invention. For a micro plasma source array, the consistency of each micro source is very high, and a surface plasma with very high consistency can be obtained. In practical applications, it is necessary to adjust the distribution of the plasma sources to obtain higher film formation consistency. The plasma sources of the microarray can be grouped and controlled in the design. As shown in Figures 20A-C, the plasma source array is divided into three partitions: red, green, and pink. Each partition is controlled by an independent plasma power supply, so that the three partitions have different plasma source power densities. The plasma source can have a bias.

[0134] Figure 21 shows a chemical vapor deposition system using microvalves. A single or multiple substrates are placed horizontally on a susceptor, which may be rotatable. Multiple horizontal microvalves are located on the sides of the substrate. This allows the precursor to flow horizontally from left to right across the substrate surface. When the flow is laminar, epitaxial layers can be grown.

[0135] A showerhead with microvalves is located above the substrate. In the first application of the showerhead, when the horizontal laminar flow is the precursor, it operates in epitaxial growth mode. The showerhead operates in diffuse purge mode, injecting purge gas and / or etching gas through the top diffuse layer. Since the laminar precursor below now flows over the substrate surface, the diffuse gas serves only to depress the laminar boundary layer, increasing the growth rate. It also protects the showerhead from precursor deposition and prevents defects caused by gas-phase nucleation and growth of particles in the diffuse layer. This is epitaxial growth mode. Another operating mode of the showerhead is cycling CVD epi. For high-defect epitaxial processes such as silicon carbide epitaxy, when epitaxial growth reaches a certain thickness, the showerhead switches to etch mode. At this point, the horizontal precursor injection stops, and even the etching gas is injected. The showerhead simultaneously injects etching gas. Because etching gas has a higher etching rate at defects, it can quickly eliminate defects in epitaxial growth. Once defects are removed, they are eliminated. The showerhead returns to epitaxial growth mode, and the horizontal injection continues. This cycle repeats, resulting in the growth of a defect-free (silicon carbide) epitaxial layer. Furthermore, the micro-discharge plasma array described in this invention can be located behind the MV to reduce the growth and etching temperatures and increase the reaction speed.

[0136] Although various embodiments of the present invention have been described above, it should be understood that they are presented by way of example only and not limitation. It will be apparent to those skilled in the relevant art that various combinations, modifications, and variations may be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely in accordance with the appended claims and their equivalents.

Claims

1. A chemical vapor reaction device for semiconductors and pan-semiconductors based on microvalve mass flow control, characterized in that: include: A plurality of nozzles are connected to a plurality of microvalves, wherein the gas passing through the nozzles is controlled by the plurality of microvalves, and the gas flows to the substrate after passing through the nozzles to perform semiconductor processing, wherein the microvalves are configured to adjust their openings to adjust the flow rate of the gas passing through the nozzles.

2. The chemical vapor reaction device according to claim 1, characterized in that: The microvalve includes a proportional control valve, and the proportional control valve includes a diaphragm valve.

3. The chemical vapor reaction device according to claim 1, characterized in that: The microvalve is connected to a pressure sensor and a temperature sensor, wherein the microvalve is configured to perform mass flow control on the gas passing through the nozzle based on a pressure flow control rate.

4. The chemical vapor reaction device according to claim 1, characterized in that: The microvalve includes a heater, a laminar flow element, a pressure sensor, and a temperature sensor, wherein the microvalve is configured to control the mass flow of gas passing through a nozzle based on a temperature flow control rate.

5. The chemical vapor reaction device according to claim 1, characterized in that: Multiple microvalves are closely arranged on a plane; and / or A plurality of nozzles are arranged below a plane where the microvalves are arranged, wherein the plurality of nozzles are closely arranged so that the gas passing through the nozzles covers the substrate to be processed.

6. The chemical vapor reaction device according to claim 1, characterized in that: The multiple gases flow toward the substrate to be processed after passing through the nozzle, wherein the multiple gases are configured to be mixed after passing through the nozzle.

7. The chemical vapor reaction device according to claim 6, characterized in that: The nozzles of different types of gases are closely arranged and staggered with each other.

8. The chemical vapor reaction device according to claim 6, characterized in that: At least two of the multiple gases share the same microvalve.

9. The chemical vapor reaction device according to claim 6, characterized in that: The invention comprises a plurality of shower head units which are closely arranged on a plane, wherein the upper part of the shower head unit is connected with a micro valve, and the lower part of the shower head unit is provided with a nozzle.

10. The chemical vapor reaction device according to claim 9, characterized in that: The spray head unit is polygonal, fan-shaped or arc-segment-shaped.

11. The chemical vapor reaction device according to claim 1, characterized in that: The semiconductor processes include chemical vapor deposition, plasma chemical vapor deposition, atomic layer deposition, plasma atomic layer deposition, plasma ashing, photolithography, chemically assisted plasma etching, and plasma etching.

12. The chemical vapor reaction device according to claim 1, characterized in that: The outer diameter of the microvalve is less than or equal to 1.125 inches; and / or The number of the valves is greater than or equal to 7.

13. The chemical vapor reaction device according to claim 3, characterized in that: Also includes: A plasma source is disposed between the microvalve and the substrate.

14. The chemical vapor reaction device according to claim 13, characterized in that: The plasma source includes inductively coupled plasma, capacitively coupled plasma, microwave plasma, hollow cathode, dielectric barrier discharge structure; and / or The plasma source includes a micro plasma source or a plasma source micro array, wherein the plasma source micro array includes a micro discharge structure, a dielectric barrier discharge structure or a hollow cathode.

15. The chemical vapor reaction device according to claim 14, characterized in that: The cavity of the micro-discharge structure serves as a gas flow channel of the shower head unit.

16. The chemical vapor reaction device according to claim 15, characterized in that: The micro-discharge structure is arranged in a gas flow channel through which a gas insensitive to plasma passes.

17. The chemical vapor reaction device according to claim 1, characterized in that: Multiple nozzles are arranged above the substrate, and the gas flows toward the substrate in a direction perpendicular to the substrate plane; or A plurality of nozzles are arranged on the side of the substrate, and the gas flows toward the substrate in a direction parallel to the substrate plane.

18. The chemical vapor reaction device according to claim 1, characterized in that: The gas pipeline without the function of uniform gas distribution or plasma chamber is constructed so that the microvalve is as close as possible to the substrate to eliminate the dead volume.

19. A semiconductor device, characterized in that: include: A shower head is arranged above the substrate and performs diffuse blowing on the top of the substrate; as well as A horizontal injection valve is arranged on the side of the substrate, and the horizontal injection valve is configured to inject laminar flow to enable the substrate to undergo epitaxial growth, wherein the epitaxial growth includes etching and cyclic etching epitaxy, wherein silicon, silicon carbide, gallium nitride, and gallium oxide are epitaxially grown, wherein the shower head and / or the horizontal injection valve is provided with a plasma source microarray.

20. The semiconductor device according to claim 19, wherein The plasma source microarray is configured to perform zone control so that different zones of a plane obtain different plasma power densities and / or bias voltages or control pulses.

21. The semiconductor device according to claim 20, wherein: The plasma source microarray has a bias voltage device, and the bias voltage device includes an AC bias or a DC bias.

22. A semiconductor device, characterized in that: include: a plurality of microvalves configured to control the flow of gas to the substrate; as well as a plasma source disposed between the microvalve and the substrate; The plasma source includes inductively coupled plasma, capacitively coupled plasma, microwave plasma, hollow cathode, dielectric barrier discharge structure; and / or The plasma source includes a micro plasma source or a plasma source micro array, wherein the plasma source micro array includes a micro discharge structure, a dielectric barrier discharge structure or a hollow cathode.

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