HORIBA, Ltd. will be launching the DZ-100 ultra-thin Mass Flow Controller (MFC) this spring. The DZ-100 controller is counted as one of the MFCs that the HORIBA Group has developed itself. Gas flow conditions used in the semiconductor manufacturing process are becoming more and more complex as semiconductor devices become increasingly miniaturized and highly integrated. The limited size of the gas box where MFCs are typically installed makes it difficult to increase the number of MFCs to meet the complicated flow conditions. The ultra-thin MFC DZ-100 inherits the high sensitivity and broad range of flow control technology used in HORIBA STEC’s mainstream product, the pressure-insensitive MFC D500, yet has its module width reduced from 28.575 mm (1.125 inches) to 10 mm, roughly a third of the existing width, without performance loss due to size reduction, and weighs 70% less at 230g.
MFCs are the key components for controlling etching, coating, and other process gases in semiconductor manufacturing equipment. HORIBA STEC entered the semiconductor industry by developing Japan’s first MFC in 1980. Since then, HORIBA STEC has constantly developed and provided global manufacturers of semiconductors and semiconductor manufacturing equipment with industry-leading MFCs that use piezo valves*2, come in an all-metal design, and feature digital I/O and internal signals.
In recent years, the semiconductor process has become complex as semiconductor devices become increasingly miniaturized and highly integrated. This demands diverse flow conditions for introducing gas into the chamber. Adding more MFCs per chamber is the preferred approach for meeting increasingly diverse gas flow conditions, but the size of the gas box where MFCs are housed is limited given that numerous control and measuring devices are connected around the chamber of semiconductor manufacturing equipment. HORIBA STEC developed the DZ-100 to meet the needs of the semiconductor industry with a module that measures 10-mm wide, roughly a third of the commonly used 1.125-inch (28.575-mm) wide module. The thinner the MFC, the more modules that can be installed in the gas box. Moreover, if the gas box can be downsized, it can be mounted closer to the chamber to improve gas replacement speed and provide precise gas control. HORIBA STEC, a long-running supplier of thin-profile MFCs for minimal fab*3 use, designed this DZ-100 product specifically for mass production, by reviewing the components and internal structure.
*2 Piezo valve: This valve uses a piezo actuator that converts an applied voltage into displacement. The actuator has a large thrust and contributes to an all-metal design.
*3 Minimal fab: This refers to small-footprint equipment suitable for the high-mix, low-volume production of semiconductors. The equipment is jointly developed by the Minimal Fab Promoting Organization and participating company members.
The DZ-100 inherits the same CRITERION™ technology—a differential pressure detection system for laminar viscous flow ranges—used on HORIBA STEC’s MFC, the D500. This innovative technology controls the mass flow of various gases with high precision. As with the D500, the user-configurable DZ-100 supports multi-range and multi-gas applications. The compact design of the MFC reduces the internal volume of the internal gas flow path, and the optimized control algorithm improves response characteristics. It uses a compact CPU with high processing capacity, and the piezo drive circuit and control CPU are installed in the MFC module while the power supply components are housed in a separate small control box. Up to four MFC modules can be controlled by connecting them with the dedicated miniature connectors.
Differential pressure detection system for laminar viscous flow ranges
All gases introduced into an MFC pass through a component, called a “flow restrictor,” which creates a pressure difference. The difference in pressure before and after this component is converted into mass flow. HORIBA developed a non-linear restrictor by modifying the structure that creates the laminar flow. This enhances flow-measuring accuracy even in low flow conditions, where the pressure difference is small. HORIBA used its Precision Flow Measurement System, installed at the HORIBA Reno Technology Center in the US, to measure the correlation of pressure, temperature, and flow volume for various process gases. Data for more than 50,000 measurement points were compiled in a centralized database and used to calculate the optimal gas-specific correction factors that are installed in the MFC. The pressure-insensitive MFC uses information from pressure and temperature sensors to compute mass flow at high speed and feeds the results back to the control valve.