Non-contaminating pressure transducer module

Abstract

A non-contaminating pressure transducer module having an isolation member is disclosed. The isolation member isolates a pressure sensor within the transducer module from exposure to ultra high purity fluids flowing through a conduit in the module without significantly affecting the accuracy of the pressure measurement. The transducer module may be positioned within a fluid flow circuit carrying corrosive materials, wherein the pressure transducer module produces a control signal proportional to either a gauge pressure or an absolute pressure of the fluid flow circuit. The pressure transducer module of the present invention also avoids the introduction of particulate, unwanted ions, or vapors into the flow circuit.

Description

BACKGROUND OF THE INVENTIONI. Field of the InventionThis invention relates generally to non-contaminating pressure transducer modules, and more particularly relates to a pressure transducer module that effectively operates within Ultra High Purity (UHP) processing equipment that utilize UHP chemicals and require UHP conditions. The pressure transducer module of the present invention provides a continuous measurement of the pressure within a fluid flow circuit of the UHP processing equipment without contaminating the fluid within the circuit. An isolation member .[.which.]. isolates a pressure sensor from the chemically corrosive fluid flow. The pressure sensor adjoins the isolation member without compromising the accuracy of the pressure measurement or increasing the risk of fluid contamination. The isolation member may be interchangeable and eliminates the need to submerge the pressure sensor in an oil or other fluid, thereby eliminating potential contaminants to the fluid flow cha...

AI Technical Summary

Benefits of technology

The purpose of the present invention is to provide a pressure transducer module that effectively operates within a fluid flow circuit of UHP processing equipment over a wide range of temperatures with minimal affects on the accuracy and resolution of the pressure measurement without requiring sensor fluids. The pressure transducer module of the present invention may be coupled to a flow circuit of corrosive fluid, wherein either the gauge pressure or absolute pressure within the flow circuit is determined.

Yet another object of the present invention is to provide a pressure transducer module having an isolation member that is in direct contact and adjoining a pressure sensor, wherein the isolation member acts to isolate the sensor and associated electronic circuitry from potentially corrosive processing chemicals and precludes introduction of contaminating substances into the processing fluids being transported.

Problems solved by technology

During the processing of semiconductor substrates, the substrate is commonly subjected to chemically corrosive fluids and high temperatures.

A highly corrosive environment may be created when aggressive processing chemicals are delivered to the processing equipment.

Of course, anything mechanical is subject to potential leakage and such leakage can create extremely hazardous conditions both to the processing of semiconductor wafers or other products and also to personnel who may have to tend and maintain the processing equipment.

First, a change in pressure within the system may indicate leakage within the system.

When highly corrosive hazardous chemicals are used, such corrosive atmospheric environments are extremely hard on the monitoring and sensing equipment.

Further, the monitoring and sensing equipment may transmit wafer damaging particulate, ions, or vapors as a result of exposure to the corrosive atmospheric environment.

Metals, which are conventionally used in such monitoring devices, cannot reliably stand up to the corrosive environment for long periods of time.

Significantly, a mere substitution of materials in the monitoring device oftentimes produces a device with other deficiencies, including leaks and inoperativeness.

Although pressure sensors have generally been developed for use in other applications, these sensors are not particularly well suited for use in semiconductor substrate UHP processing equipment.

When subjected to chemically corrosive fluids used in semiconductor substrate processing equipment, the processing fluids permeate through the coating of the protective member, corrode the metal and permeate back through the coating thereby contaminating the processing fluids.

This contamination is not acceptable in UHP processing equipment.

Further, it is believed that the stiffness of the metal coated '192 protective member decreases the accuracy and resolution of the measured pressure.

Hence, use of the sensors disclosed in the '192 and '139 patents are not acceptable in the UHP processing equipment.

Thus, when positioned in-line within the fluid flow circuit of semiconductor substrate processing equipment, the sensor fluid or oil contained within the housing of Zavoda would permeate through the protective member and contaminate the fluid within the fluid flow circuit.

Also, a diaphragm having a wavelike cross-section as described by Zavoda '139 is believed to decrease the accuracy of pressure measurements when measured over a wide range of temperatures.

Further, it is believed that adjoining the sensor to the diaphragm disclosed by Zavoda would result in an inoperable or unreliable pressure sensor having minimal accuracy and resolution.

A change in pressure within the fluid flow of the processing equipment affects the oil pressure within the cavity of these devices.

Also, the oil within the cavity typically has large thermal expansions which cause large deflection changes in the protective member.

The large deflection changes in the protective member increases the likelihood that the oil within the cavity will leak into the fluid flow, contaminating the flow circuit of the processing equipment.

Also, the accuracy of the pressure gauge is negatively affected by the large thermal expansions of the oil.

When the valve is opened, fluid from the circuit flows through the valve and a certain amount of contaminating back flow results.

Thus, the devices disclosed by Sorrell and Zavoda are not suitable for use in environments where high purity is desired.

Although utilizable in high purity environments, the '035 patent does not describe a device capable of measuring pressure within a fluid flow conduit of the processing equipment.

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