Semi-conductor Quartz-tube Furnace System Upgrade

Price Technology enjoyed working with the semi-conductor industry consultant on this ambitious project of upgrading quartz-tube electric furnaces.  These quartz-tube furnaces are used for  high-temperature heat treating and film deposition on 6-inch diameter wafers used in the semi-conductor industry.  Some of the furnaces operate under atmospheric pressures while others operate under high-vacuum conditions.  Multiple electric heating zones in each furnace maintain very high temperatures.  Proprietary gases are introduced into the furnaces to maintain ultra-pure environments and are used in the deposition process.  Multiple recipe steps control all process variables to very close tolerances throughout the process.

A large international semi-conductor company’s research lab had two furnace banks with three quartz-tube electric furnaces in each bank.  The existing computer-based control system was obsolete and failing as well as the temperature, pressure, and gas control equipment.  The research lab entrusted the semi-conductor industry consultant to rebuild the furnaces from top to bottom.

Source end showing vacuum equipment during assembly.

Price Technology was proud to be part of this challenging project and to provide valuable control system services.  Price Technology was entrusted to provide:

· Piping & Instrumentation Diagram (P&ID)

· Control Cabinet & Bill Of Material

· Input/Output Specification Spreadsheet

· Electrical Schematic Diagrams

· Control Cabinet Design, Assembly, & Wiring

· Sequence Logic Diagrams

· PLC Programming

· Recipe Spreadsheet

· PC-based Operator interface Programming

View of Control Panel Interior for Furnace Bank #1.

View of Remote Relay and Terminal Board.

CONTACT: Kevin Price

Price Technology

110 Manatawny Road

Oley, PA 19547

Phone: 610-689-0300







Screen Print of Bank #1 Furnace #2 Process HMI Home Screen.

Each furnace is controlled by an AutomationDirect.comTM Koyo DL205 PLC.  Each furnace PLC communicates with the operator interface computers via Ethernet network.  Redundant safety logic for each furnace is provided by an AutomationDirect.comTM Koyo DL06 PLC.  Redundant safety logic PLCs communicate with the furnace PLCs via RS232 serial links. Dedicated safety controllers provide hard-wired safety circuits.  Desk-top computers run the supervisory control & data acquisition (SCADA) software LookoutTMDirect.  The LookoutTM SCADA software is developed by National Instruments, and is one of the industries’ leading control & data acquisition software products.  Desk top computer software also handles the recipe development and recipe management.



The PLC input and output modules connect to the furnace hardware, such as gas mass flow controllers & gas valves, vacuum pump controllers, vacuum sensors, vacuum controllers, temperature, gas, & pressure safety systems, heating zone SCR controllers, wafer loading/unloading stepping motor drives.


Due to the many furnace types and the unique control requirements for each furnace, the project developed over time.  The initial project meeting was held in March 2009.  The furnace rebuilding and control installation progressed throughout the year.  The various furnaces were brought online, tested, and modified as needed.  The final PLC revision was issued January 2010.