In the semiconductor manufacturing process, the vacuum system is the core technology for wafer etching, thin film deposition, ion implantation, and other processes “cornerstone”——Its pressure stability directly affects the line width accuracy, film uniformity, and yield of the chip. And as a vacuum system, the vacuum gauge“Stress Perception Core”Deviation in selection may lead to process loss of control, product scrapping, and even equipment damage.

The vacuum environment in the semiconductor industry has “Wide pressure span, high cleanliness requirements, medium complexity”The three major characteristics are that traditional universal vacuum gauges are often difficult to adapt to. This article focuses onPressure range, accuracy, and pollution resistance The three core indicators, combined with the disassembly and selection logic of semiconductor process scenarios, help engineers avoid selection errors and achieve precise matching.

1、 Pressure range: Match the entire process of the manufacturing process, reject “Insufficient coverage”or“Excessive redundancy”

The vacuum requirements for semiconductor processes span a wide range, from wafer handling “Coarse vacuum”（10⁵~10² Pa）To the etching process“高真空”（10⁻¹~10⁻⁵ Pa）From thin film deposition to“超高真空”（10⁻⁶~10⁻¹⁰ Pa）The requirements for pressure ranges vary greatly among different processes. The core of selection is“Accurately covering the required interval of the process”Rather than blindly pursuing“Full range”.

1. Match pressure ranges according to process scenarios

2. Selection avoidance: Avoid pitfalls“Range misalignment”

misconception 1: Use “Wide range vacuum gauge”Covering the entire process——For example, using an ultra-high vacuum gauge to monitor the coarse vacuum range not only significantly reduces measurement accuracy (errors may exceed±50%）Due to range redundancy, the response speed may slow down, making it difficult to capture pressure fluctuations in a timely manner.

misconception 2A single vacuum gauge covers multiple process stages ——Semiconductor production lines often require switching between different processes, it is recommended to use“compound vacuum gauge”(such as capacitive type)+Ionizing combination or separately configuring vacuum gauges with appropriate ranges in different process stages to ensure accurate pressure monitoring throughout the entire process.

2、 Accuracy: More than just looking “Parameter values”More importantly, it is necessary to adapt to the tolerance of process errors

The requirement for pressure accuracy in semiconductor technology can be called “harsh”For example:3nmThe etching process of the manufacturing process has pressure fluctuations exceeding±0.1 PaThis may lead to line width deviation, directly affecting chip performance. But the vacuum gauge“precision”It's not that the higher the better, the key is“Match with tolerance for process errors”At the same time, taking into account both“repetitiveness”and“long-term stability”.

1. The core evaluation dimension of accuracy

⑴Absolute accuracy: Refers to the deviation between the measured value and the actual pressure (such as ±0.5% FS）, applicable to pressureAbsolute value requires high processes (such as pressure calibration for thin film deposition).

⑵Relative accuracy: Refers to the measurement deviation during pressure changes (such as ±0.1%Readings are suitable for processes that require monitoring pressure fluctuations, such as dynamic pressure control in plasma etching.

⑶long-term stabilitySemiconductor equipment typically requires7×24Continuous operation for hours, the zero drift of the vacuum gauge should be controlled within the allowable range of the process (it is recommended that the monthly drift should not exceed)±0.05% FS）Otherwise, it will cause process parameter drift, increase calibration frequency and downtime costs.

2. Select based on process accuracy requirements

⑴High precision requirements (such asALDIon implantation: SelectAbsoluteprecision≤±0.2% FSLong term drift≤±0.03% FSFor vacuum gauges, priority should be given to models with automatic calibration function to reduce manual maintenance costs.

⑵Conventional precision requirements (such as wafer handling, cleaning): SelectAbsoluteprecision≤±1% FSA vacuum gauge is sufficient, with a focus on cost-effectiveness and response speed.

3. Easily overlooked“Factors affecting accuracy”

⑴Environmental interferenceThe temperature fluctuations and electromagnetic radiation in the semiconductor workshop can affect the accuracy of the vacuum gauge, so it is necessary to choose a temperature compensation function and anti electromagnetic interference（EMC）Certified products (such as those that meet the requirements)IEC 61326Standard).

⑵Installation methodThe installation position and pipeline length of the vacuum gauge may cause pressure loss. When selecting, it is necessary to confirm whether the product supports it “Remote measurement”or“Multi point calibration”To offset the accuracy deviation caused by installation.

3、 Anti pollution: semiconductor vacuum system “lifeline”To avoid“Once polluted, it will be scrapped”

In semiconductor processes, there may be photoresist residue, metal vapor, and corrosive gases (such as...) in the vacuum systemCl₂TheF₂）When pollutants are present, these substances will adhere to the sensor surface of the vacuum gauge, causing reading drift, slow response, and even sensor damage——Once the vacuum system of semiconductor equipment is contaminated, the cleaning cost is very high, and it may also lead to the scrapping of the entire batch of wafers. Therefore, anti pollution is a key factor in the selection of semiconductor vacuum gauges“Key implicit indicators”.

1. Core evaluation criteria for anti pollution

⑴Sensor materialPrioritize the use of corrosion-resistant and high-temperature resistant sensor materials such as ceramics and sapphires, and avoid using metal sensors (which are susceptible to corrosive gases).

⑵structural design: Select “Fully sealed sensor”“Detachable and washable probe”The vacuum gauge is convenient for regular cleaning; Avoid choosing an open design where the sensor is exposed to a vacuum environment.

⑶Anti condensation abilitySome processes may generate water vapor (such as drying wafers after cleaning), and vacuum gauges need to have anti condensation function to prevent sensor condensation from causing short circuits or reading distortion.

2. Select by pollutant type

3. The added value of anti pollution: reducing maintenance costs

The equipment downtime cost of semiconductor production lines is very high (some wafer fabs experience downtime losses exceeding one hour) 10 A vacuum gauge with strong anti pollution properties can significantly extend the maintenance cycle, costing tens of thousands of yuan——For example, a regular vacuum gauge may3 Cleaning is required once a month, while anti pollution models can be extended to12 Months, indirectly improving production efficiency.

4、 Selection Summary:3 Step by step to achieve precise matching

1.Clarify the process boundaryFirst, sort out the target process “Pressure range, accuracy requirements, pollutant types”Create a list of selection requirements (e.g. plasma etching process, pressure range)10⁻ ²~10¹ Pa, accuracy±0.1%Reading, requires resistanceCl₂Corrosion).

2.Match core indicators: Press “The pressure range covers the process interval→Accuracy adaptation error tolerance→Anti pollution response to pollutants”Prioritize the selection of semiconductor industry specific models (such as those that meet the requirements) through sequential screeningSEMI F40/F47Standard products).

3.Verify additional requirementsConfirm the interface compatibility of the vacuum gauge (such asCFFlangesKFFlanges), signal output methods (such as4-20mATheRS485）Is it supportedPLCLinkage control to avoid installation difficulties caused by interface mismatch.

Conclusion

The selection of semiconductor vacuum gauge is essentially “Accurate matching of process requirements and product performance”——The pressure range determines“Can it be used”Accuracy determines“Accurate use”The resistance to pollution determines“Used for a long time”In3nmToday, with excellent manufacturing processes becoming mainstream, the selection deviation of vacuum gauges may be amplified by the process, directly affecting chip yield.

It is recommended that engineers communicate with suppliers based on the specific parameters of their own process (such as pressure range, pollutant composition, accuracy requirements) before selecting, and conduct sample testing if necessary to ensure that the vacuum gauge is not only “Compliant with parameters”, more capable“Adaptation scenario”Only by selecting the right vacuum gauge can we build a solid foundation for the stable operation of semiconductor vacuum systems“Perception defense line”.

Hangzhou Yushi Technology Co., LtdFocusing on providing technical services and solutions related to flow, pressure, vacuum detection and control for industrial and scientific research customers, the company acts as an agent and distributor in the United StatesALICAT、 Swiss Vogtlin, American MKS, Japanese EBARA and other brands, combined with their agent products, provide customers with high-quality flow and pressure monitoring solutions, aiming to improve customers' research and production efficiency, improve their manufacturing processes, and promote their scientific research and innovation progress.