Rapid Thermal Process

SYSTEM DESCRIPTION

The AccuThermo AW410 is a manual desktop atmospheric rapid thermal processing (RTP) system for 2 to 4 inch wafers, which uses high intensity visible radiation to heat single wafers for short process periods of time at precisely controlled temperatures. The process periods are typically 1-600 seconds in duration, although periods of up to 9999 seconds can be selected. These capabilities, combined with the heating chamber’s cold-wall design and superior heating uniformity, provide significant advantages over conventional furnace processing.The AccuThermo RTP system consists of an oven unit and a controller computer running the

Advanced Allwin21 AW-900 controller software

. The wafer to be processed is placed on a quartz tray that slides into a quartz isolation tube in the oven unit. Two banks of lamps, one above the quartz tube and one below it, provide the source of energy for heating the wafer. The lamps can be controlled manually and automatically from the controller computer.
The AW-900 control software allows full control and diagnostics of the AccuThermo RTP system. In addition, it allows the creation of recipes for automated control of the temperature and, optionally, process gas flow. The control software uses a set of operating instructions known as recipes to automatically control the AccuThermo RTP system. These recipes are created by the Process Engineer to monitor and control the parameters of the processing cycle. The Operator then uses the software to select and run the process parameters (steady state temperature, process time, ramp rates, etc.). The AW-900 software is also used to create, delete, copy, modify and store the recipes and to execute system diagnostics.

KEY FEATURES
Closed-loop temperature control with pyrometer or thermocouple temperature sensing.
Precise time-temperature profiles tailored to suit specific process requirements.
Fast heating and cooling rates unobtainable in conventional technologies.
Consistent wafer-to-wafer process cycle repeatability.
Elimination of external contamination.
Small footprint and energy efficiency.
The watchdog timer shuts down the lamps to prevent run-away heating of the wafer.

APPLICATIONS
The AccuThermo RTP system is a versatile tool that is useful for many applications:
Ion Implant Activation
Polysilicon Annealing
Oxide Reflow
Silicide Formation
Contact Alloying
Oxidation and Nitridation
GaAs Processing

HEATING, COOLING, AND TEMPERATURE MEASUREMENT

The following list contains the key features of the AccuThermo RTP system heating, cooling and temperature measurement systems:
High-intensity visible radiation heats wafers for short periods of 1 to 9999 seconds at precisely controlled temperatures in the 400°C to 1200°C range. (1 to 600 second heating periods are used typically.)
Tungsten halogen lamps and cold heating chamber walls respectively allow fast wafer heating and cooling rates.
The system delivers time and temperature profiles tailored to suit specific process requirements.
Pyrometer or thermocouple sensing offers precise closed-loop temperature control.
Cooling N2 flows around the lamps and quartz isolation tube
MFC controlled gases (up to six) flow through the heating chamber for purge and/or process purposes.

SYSTEM SPECIFICATIONS

Following are the specifications for the AccuThermo Rapid Thermal Processor (RTP) system.
Wafer handling: Manual loading of wafer into the oven, single wafer processing.
Wafer sizes: 2″, 3″, 4″ wafers.
Ramp up rate: Programmable, 10°C to 200°C per second.
Recommended steady state duration: 0-300 seconds per step.
Ramp down rate: Programmable, 10 C to 250 C per second.Ramp down rate is temperature-and-radiation-dependent and the maximum is 125 C per second.
Recommended steady state temperature range: 150°C – 1150 C
ERP temperature accuracy: ±1°C, when calibrated against an instrumented thermocouple wafer (ITC).
Thermocouple temperature accuracy: ±0.5°C
Temperature repeatability: ±0.5°C or better at 1150°C wafer-to-wafer. (Repetition specifications are based on a 100-wafer set.)
Temperature uniformity: +5°C across a 6″ (150 mm) wafer at 1150°C. (This is a one sigma deviation 100 angstrom oxide.) For a titanium silicide process, no more than 4% increase in non-uniformity during the first anneal at 650°C to 700°C.
Process/Purge gas inputs: Any inert and/or non-toxic gas regulated to 30 PSIG and pre-filtered to 1 micron. Typically, Nitrogen (N2), oxygen (O2), argon (Ar), and/or helium (He) are used.+2.5°C