Specialty Gas Delivery Systems in Semiconductor Manufacturing

In the microcosm of semiconductor manufacturing, specialty gases (SPGs) are the "lifeblood" of critical processes such as etching and deposition. The specialty gas delivery system serves as the "highway" that transports this lifeblood safely and precisely to process tools. Its design and performance directly determine the efficiency, yield, and safety of chip fabrication.

Because different gases have varying physical properties and consumption volumes, several delivery configurations exist. However, most specialty gas delivery systems consist of five core components. The following introduces their structure and function in detail.

Gas Supply Systems (BSGS, GC, GR)

① Bulk Specialty Gas Supply System (BSGS)

The Bulk Specialty Gas Supply System (BSGS) is designed for high-volume, continuous, and uninterrupted delivery of hazardous gases such as SiH₄, NF₃, NH₃, N₂O, and HCl in advanced manufacturing facilities (semiconductor, TFT-LCD, solar, LED). It provides safe, automated, and stable supply for high-throughput production.

System Composition

Gas Source Interface: Compatible with ISO containers, tube trailers, Y-cylinders, drums, and cylinder bundles.

Cabinet/Rack:

● Structure: 2 mm cold-rolled steel with corrosion-resistant coating (optional stainless steel) and large safety glass window.

● Safety: Auto-locking doors, UL fire sprinklers, dual 6" exhaust outlets, forced ventilation.

Gas Panel: Includes pneumatic diaphragm valves, dual-stage regulators, filters, vacuum venturis, Joule–Thomson heaters, 316L EP electropolished tubing (Ra ≤ 0.25 μm), and VCR fittings.

Control and Sensing: PLC (Siemens/Mitsubishi), 7" HMI touchscreen, pressure sensors, weighing scales, temperature probes, and flame/smoke/leak detectors.

Distribution Unit: Integrated with VMB or VMP for multi-tool supply.

Abatement: Purge gases are treated via scrubbers or adsorption towers before venting.

Applications

● Diffusion/LPCVD: NH₃, SiH₄, TEOS

● Etching: NF₃, Cl₂, HBr

● Ion Implantation: BF₃, AsH₃, PH₃

② Gas Cabinet (GC)

The Gas Cabinet (GC) is a fully enclosed micro gas supply station used in semiconductor, photovoltaic, biopharmaceutical, and laboratory environments for the safe storage, distribution, and continuous delivery of hazardous specialty gases (flammable, explosive, highly toxic, strongly corrosive). Hazardous cylinders are securely “locked” inside an explosion-proof cabinet, while PLC control and HMI integration enable either unattended or minimal-attended operation. This makes the GC a critical node in the "last mile" of the specialty gas delivery line between the facility and process tools.

Functional Role

● Supplies small-flow, intermittent, or continuous specialty gases (PH₃, SiH₄, ClF₃, WF₆, NH₃, HCl, etc.) to 1–2 process tools.
● Integrates key safety features including explosion-proof and fire protection, leak prevention, automatic gas switching, purge and vacuum evacuation, emergency shutdown, and alarm transmission—to ensure human–machine isolation with uninterrupted gas supply.

Upstream/Downstream Relations

Upstream Sources: Y-cylinder, tube cylinder, ISO containers, or BSGS pipelines.

Downstream Connections: To VMB/VMP or directly to process tools.Interfaces with VMB/VMP systems or directly connects to process tools.

Through combined features such as explosion-proof enclosure, ultra-high purity gas paths, automated switching/purging, and multi-level safety interlocks, the GC effectively "cages" high-risk gases while maintaining tool uptime and preventing contamination. As such, it is an indispensable gas supply unit in advanced manufacturing sectors including semiconductors, photovoltaics, and biopharmaceuticals.

③ Gas Rack (GR)

The Gas Rack (GR) is a semi-open or open system for safe distribution of inert and less hazardous gases (N₂, Ar, He, H₂, O₂, CDA). With a simpler structure and lower cost than a GC, it is suited for bulk or auxiliary gases that are non-toxic, non-flammable, and non-corrosive, serving as an intermediate distribution node between facility supply, cleanroom, and process tools.

Gas Distribution Equipment (VMB, VMP)

Often referred to as the "last mile" in SPG delivery, Valve Manifold Boxes (VMBs) and Valve Manifold Panels (VMPs) split a single source into multiple lines for different tools.

VMB (Valve Manifold Box):

Enclosed unit with exhaust ventilation, explosion-proof housing, and abatement.

Designed for hazardous gases (SiH₄, NH₃, Cl₂, WF₆, etc.).

Allows purging of any branch line without affecting others.

VMP (Valve Manifold Panel):

Open-panel structure, usually for inert gases（N₂, Ar, He, O₂, CDA）.

Low-cost and simple, allows centralized pressure regulation.

Suitable for laboratories or production environments with low-risk gases.

Together, VMBs and VMPs ensure safe and flexible multi-tool gas distribution.

Exhaust Treatment Systems

During cylinder changeover or purging, hazardous gases cannot be discharged directly. Exhaust treatment systems (scrubbers, adsorption towers) remove or neutralize toxic, corrosive, and flammable gases to meet environmental standards before release. These systems are also essential for treating process tool exhaust.

Gas Monitoring and Detection Systems (GMS, GDS)

Gas Management System (GMS)

The GMS monitors equipment operating parameters such as cylinder pressure, flow rate, and purity in real-time.

● Real-time system monitoring

● Gas distribution control and valve actuation

● Purity and impurity analysis

● Event logging and historical data queries

● Remote alarms and system shutdown

Gas Detection System (GDS)

The GDS provides environmental monitoring for leaks, with alarm thresholds based on TLV values.

● Real-time gas concentration detection

● Alarm signals (visual/acoustic) at preset thresholds

● Automatic control of ventilation, sprinklers, and gas cutoff valves

● Data transmission for remote safety monitoring

Typically, two alarm levels are implemented: Level-1 at 50% of the TLV, and Level-2 at the full TLV.

Gas Piping

Gas piping is the "lifeline" between sources (GC, GR, BSGS) and process equipment. Its design, material, and installation directly affect reliability, purity, and safety.

Common Materials

316L SS: corrosion-resistant, suitable for most SPGs.Strong corrosion resistance and low internal surface roughness, suitable for most specialty gases (such as SiH₄, NH₃, Cl₂).

316L SS -EP: electropolished, Ra ≤ 0.25 μm surface roughness, optimal for electronic-grade gases.After electropolishing, the internal surface achieves ultra-high smoothness (Ra ≤ 0.25 μm), making it suitable for high-purity gases (e.g., electronic-grade specialty gases).

PTFE-lined Pipe: Excellent corrosion resistance, suitable for highly corrosive gases (such as Cl₂, HCl), though with lower mechanical strength.

Special Configurations

Double Containment Tubing: Inner 316L-EP tube with outer 316L shell for highly toxic gases; leak detection integrated.

Heated Lines: For gases requiring temperature-controlled delivery (e.g., H₂S, CO₂).

Proper material selection, installation, and qualification ensure both gas purity and operational safety.

Safety in production is not only a matter of industrial efficiency but also of protecting lives and property. By deploying advanced detection, alarm, and abatement technologies, risks can be contained at their source, ensuring both industrial sustainability and public safety.

At LITEN FLOW, we don’t just deliver equipment—we deliver reliability, safety, and efficiency to your production line. Whether you need bulk gas supply systems, gas cabinets, racks, distribution panels, or abatement solutions, LITEN provides comprehensive, end-to-end specialty gas delivery systems tailored to your factory’s needs. Partner with us to ensure your advanced manufacturing achieves the highest standards of productivity and safety.