Method and system for adjusting radio frequency transmitting power by estimating load capacity

Abstract

The invention discloses a method and a system for adjusting radio frequency transmitting power by estimating load capacity, and belongs to the technical field of intelligent regulation and control of radio frequency transmitting power, and the method comprises the following steps: firstly establishing a corresponding table of time required for reaching a preset vacuum degree and load capacity; carrying out vacuum extraction based on a reaction cavity which is provided with a plurality of groups of loads and is used for executing a semiconductor processing process, and determining time required for reaching a preset vacuum degree; estimating the load capacity according to the time and the corresponding table; the radio frequency transmitting power of the radio frequency power supply system is adjusted based on the load capacity, so that the corresponding table of the time required for reaching the preset vacuum degree and the load capacity is established in advance, the load capacity is determined according to the time required for reaching the preset vacuum degree during vacuum extraction, and then the initial power of the radio frequency transmitting device can be determined; therefore, the adjustment time of the radio frequency transmitting device is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency transmission power intelligent control, and in particular to a method and system for adjusting radio frequency transmission power by estimating load capacity. Background Art

[0002] The RF power system is a device used to generate RF power signals. It is a core component of semiconductor process equipment. All equipment that generates plasma for material processing requires RF power systems to provide energy. Process manufacturing equipment for integrated circuits, solar cells, and LEDs (Light Emitting Diodes), such as etchers, PVD (Physical Vapor Deposition), PECVD (Plasma Enhanced Chemical Vapor Deposition), ALD (Atomic Layer Deposition), etc., are all equipped with RF power systems with different power specifications.

[0003] The RF power supply system used for plasma process generally includes an RF power generator and an impedance matcher. The RF power generator is used to generate an RF signal with a certain power level and a certain frequency, while the impedance matcher is placed between the plasma reaction chamber and the RF power generator to match the load impedance of the plasma reaction chamber with the output impedance of the RF power generator, so as to well transmit the power generated by the RF power generator to the plasma chamber, thereby exciting a sufficient amount of plasma to achieve the process requirements.

[0004] However, in practice, the power of the RF power generator is adjustable, but in order to shorten the adjustment process and time, it is best to estimate the capacity of the load in advance, so as to match the starting value of the RF power generator with the estimated load capacity. In this way, only fine-tuning is required in the subsequent adjustment process, and no large-scale adjustment is required, thereby shortening the adjustment time; therefore, it is urgent to design a load capacity prediction technology to shorten the adjustment time of the RF power generator. Summary of the invention

[0005] In order to solve the above problem, the present invention provides a method for adjusting radio frequency transmission power by estimating load capacity, comprising the following steps: First, establish a table of the time required to reach a predetermined vacuum degree and the load capacity; Based on a reaction chamber for performing semiconductor processing and provided with a plurality of groups of loads, vacuum extraction is performed to determine the time required to reach a predetermined vacuum degree; According to the time and the corresponding table, estimate the load capacity; Based on the load capacity, adjust the starting RF transmission power of the RF power system.

[0006] Preferably, in the process of establishing a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity, by setting different load capacities in the reaction chamber, selecting the first reaction chamber pressure in the reaction chamber as the benchmark value, and setting the second reaction chamber pressure as the reference value, thereby obtaining the change time of the reaction chamber pressure with different load capacities from the benchmark value to the reference value, thereby establishing a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity.

[0007] Preferably, in the process of adjusting the initial RF transmission power of the RF power supply system based on the load capacity, the initial RF transmission power is determined according to a preset correspondence table between the load capacity and the RF transmission power of the RF power supply system.

[0008] Preferably, the method further comprises a step of further fine-tuning after adjusting the initial RF transmission power of the RF power supply system based on the load capacity.

[0009] The present invention provides a system for adjusting radio frequency transmission power by estimating load capacity, comprising: A module for establishing a corresponding table between the time required to reach a predetermined vacuum degree and the load capacity is used to set different load capacities in the reaction chamber, select a first reaction chamber pressure in the reaction chamber as a reference value, and set a second reaction chamber pressure as a reference value, thereby obtaining the change time of the reaction chamber pressure with different load capacities from the reference value to the reference value, thereby establishing a corresponding table between the time required to reach a predetermined vacuum degree and the load capacity; A module for determining the time required to reach a predetermined vacuum degree, which performs vacuum extraction based on a reaction chamber provided with a plurality of load groups and performing a semiconductor processing process, and determines the time required to reach a predetermined vacuum degree; A load capacity estimation module estimates the load capacity according to the time required to reach a predetermined vacuum degree and a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity; The RF transmission power adjustment module adjusts the initial RF transmission power of the RF power supply system based on the load capacity.

[0010] Preferably, the RF transmission power adjustment module adjusts the initial RF transmission power of the RF power system according to a preset correspondence table between load capacity and initial RF transmission power of the RF power system.

[0011] The present invention discloses the following technical effects: The present invention establishes a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity in advance, obtains the time required to reach the predetermined vacuum degree by vacuum extraction of the reaction chamber, and then determines the load capacity through the above correspondence table, and then determines the starting power of the radio frequency transmitting device according to the load capacity, thereby shortening the adjustment time of the radio frequency transmitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 It is a schematic diagram of the method flow of the present invention; Figure 2 It is a schematic diagram of the method process described in the present invention. DETAILED DESCRIPTION

[0014] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0015] like Figure 1-2 As shown, the present invention provides a method for adjusting radio frequency transmission power by estimating load capacity, comprising the following steps: First, establish a table of the time required to reach a predetermined vacuum degree and the load capacity; Based on a reaction chamber for performing semiconductor processing processes provided with several groups of loads, vacuum extraction is performed to determine the time required to reach a predetermined vacuum degree; wherein the semiconductor processing process may be a process such as thin film deposition, oxidation, etching, etc.; According to the time and the corresponding table, estimate the load capacity; Based on the load capacity, adjust the starting RF transmission power of the RF power system.

[0016] Preferably, in the process of establishing a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity, by setting different load capacities in the reaction chamber, selecting the first reaction chamber pressure in the reaction chamber as the benchmark value, and setting the second reaction chamber pressure as the reference value, thereby obtaining the change time of the reaction chamber pressure with different load capacities from the benchmark value to the reference value, thereby establishing a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity.

[0017] Preferably, in the process of adjusting the initial RF transmission power of the RF power supply system based on the load capacity, the initial RF transmission power is determined according to a preset correspondence table between the load capacity and the RF transmission power of the RF power supply system.

[0018] Preferably, the method further comprises a step of further fine-tuning after adjusting the initial RF transmission power of the RF power supply system based on the load capacity.

[0019] The present invention provides a system for adjusting radio frequency transmission power by estimating load capacity, thereby realizing a method for adjusting radio frequency transmission power by estimating load capacity, comprising: A module for establishing a corresponding table between the time required to reach a predetermined vacuum degree and the load capacity is used to set different load capacities in the reaction chamber, select a first reaction chamber pressure in the reaction chamber as a reference value, and set a second reaction chamber pressure as a reference value, thereby obtaining the change time of the reaction chamber pressure with different load capacities from the reference value to the reference value, thereby establishing a corresponding table between the time required to reach a predetermined vacuum degree and the load capacity; A module for determining the time required to reach a predetermined vacuum degree, which performs vacuum extraction based on a reaction chamber provided with a plurality of load groups and performing a semiconductor processing process, and determines the time required to reach a predetermined vacuum degree; A load capacity estimation module estimates the load capacity according to the time required to reach a predetermined vacuum degree and a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity; The RF transmission power adjustment module adjusts the initial RF transmission power of the RF power supply system based on the load capacity.

[0020] Further preferably, the RF transmission power adjustment module adjusts the initial RF transmission power of the RF power system according to a preset correspondence table between load capacity and initial RF transmission power of the RF power system.

[0021] Embodiment 1: In order to shorten the process and time of power adjustment of the RF power generator, it is necessary to estimate the capacity of the load, so as to match the starting value of the RF power generator with the estimated load capacity. In this way, only fine-tuning is required in the subsequent adjustment process, and no large-scale adjustment is required, thereby shortening the adjustment time. In particular, in some semiconductor processing processes, many wafers or substrates are placed in the reaction chamber (tank or tube CVD) at one time. In this way, the load capacity (such as the number of wafers or substrates to be processed in the reaction chamber) is estimated according to the time taken to reach a certain vacuum degree, and then the RF transmission power is adjusted; the specific process is as follows: Figure 2 As shown in the figure: under the premise of fixed volume of reaction chamber, vacuum pump is first used to extract and reduce the pressure of reaction chamber from P1 to P2. The time for the pressure of reaction chamber with different loads to drop from P1 to P2 is different. For example, S1 curve (S1 curve represents the pressure change curve of reaction chamber) requires T1 time, S2 curve requires T2 time, and S3 curve requires T3 time. It can be inferred that the load represented by S1 curve is large (the load is large, the amount of air in the reaction chamber is small, and the time for the pressure to drop from P1 to P2 is short). Among them, S1 curve, S2 curve and S3 curve represent the pressure and time change curves of reaction chamber with different capacity loads from the initial state to the preset pressure by using a true pump. Among them, the load represented by S3 is the smallest. Therefore, a corresponding table between load size and time required to reach a predetermined vacuum degree is established and stored in the host computer in advance.

[0022] When executing the process, the vacuum step is performed first. At this time, the vacuum gauge detects the pressure of the reaction chamber according to the preset time, and the controller obtains the time when the pressure of the reaction chamber drops from P1 to P2. In this way, the corresponding load capacity can be determined by querying the above preset table, and then the initial power of the RF transmitting device is determined according to the relationship table between the load capacity and the initial power of the RF transmitting device, and then the starting RF transmitting power of the RF power supply system is adjusted. After that, the RF power supply system is started to output RF energy to the reaction chamber with the starting RF transmitting power.

[0023] The present invention establishes a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity in advance, obtains the time required to reach the predetermined vacuum degree by vacuum extraction of the reaction chamber, and then determines the load capacity through the above correspondence table, and then determines the starting power of the radio frequency transmitting device according to the load capacity, thereby shortening the adjustment time of the radio frequency transmitting device.

[0024] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0025] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for adjusting radio frequency transmission power by estimating load capacity, characterized in that The method comprises the following steps: First, establish a table of the time required to reach a predetermined vacuum degree and the load capacity; Based on a reaction chamber for performing semiconductor processing and provided with a plurality of groups of loads, vacuum extraction is performed to determine the time required to reach a predetermined vacuum degree; According to the time and the corresponding table, estimate the load capacity; Based on the load capacity, adjust the starting RF transmission power of the RF power system.

2. The method for adjusting radio frequency transmission power by estimating load capacity according to claim 1, characterized in that: In the process of establishing a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity, by setting different load capacities in the reaction chamber, selecting the first reaction chamber pressure in the reaction chamber as the benchmark value, and setting the second reaction chamber pressure as the reference value, thereby obtaining the change time of the reaction chamber pressure with different load capacities from the benchmark value to the reference value, thereby establishing a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity.

3. The method for adjusting radio frequency transmission power by estimating load capacity according to claim 2, characterized in that: In the process of adjusting the initial RF transmission power of the RF power supply system based on the load capacity, the initial RF transmission power is determined according to a preset corresponding relationship table between the load capacity and the RF transmission power of the RF power supply system.

4. The method for adjusting radio frequency transmission power by estimating load capacity according to claim 3, characterized in that: The method further includes the step of further fine-tuning after adjusting the initial RF transmission power of the RF power system based on the load capacity.

5. A system for adjusting radio frequency transmission power by estimating load capacity, characterized in that: Applications in semiconductor processing include: A module for establishing a corresponding table between the time required to reach a predetermined vacuum degree and the load capacity is used to set different load capacities in the reaction chamber, select a first reaction chamber pressure in the reaction chamber as a reference value, and set a second reaction chamber pressure as a reference value, thereby obtaining the change time of the reaction chamber pressure with different load capacities from the reference value to the reference value, thereby establishing a corresponding table between the time required to reach a predetermined vacuum degree and the load capacity; A module for determining the time required to reach a predetermined vacuum degree, which performs vacuum extraction based on a reaction chamber provided with a plurality of load groups and performing a semiconductor processing process, and determines the time required to reach a predetermined vacuum degree; A load capacity estimation module estimates the load capacity according to the time required to reach a predetermined vacuum degree and a correspondence table between the time required to reach a predetermined vacuum degree and the load capacity; The RF transmission power adjustment module adjusts the initial RF transmission power of the RF power supply system based on the load capacity.

6. The system for adjusting radio frequency transmission power by estimating load capacity according to claim 5, characterized in that: The RF transmission power adjustment module adjusts the initial RF transmission power of the RF power supply system according to a preset correspondence table between load capacity and the initial RF transmission power of the RF power supply system.

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