EpiCAD Screen-shot Gallery

Structure Oriented Control

   The figure above provides an illustration of the power of SOC as applied to a thermal MBE source in accomplishing a composition ramp (in this case, a linear AlGaAs composition ramp executed by varying the Al source temperature). User input simply consists of setting the start and end composition and thickness. At run-time, EpiCAD determines the required growth rate profile required of the Al source (2) and converts it to the complex temperature profile (3).

   SOC is can be applied in similar fashion to all source types to ensure accurate execution of complex profiles.
 

Real-time Control

    EpiCAD has 3 modes of operation: interactive, process run and configuration. The above shows the Status (interactive) window of a simple III-V:MBE configuration. From this screen, ALL aspects of the system can be controlled and monitored in real-time. For example, to ramp the Ga to 1 µm/hr, click the Ga setpoint HotSpot, select ramp and set the end value, ramp time and function. The view indicates a Ga ramp in progress with 4:41 m:s to go. Note also the Setpoint and Process Value summaries at the top of the screen from which the composition, doping level, growth temperature etc can be compared, providing for immediate feedback of error state.

    Other dedicated views provide control/monitoring of other system facilities. For example, the System Status Dialog allows the user to mimic the system:

Data Acquisition

    System data is displayed graphically in real-time or from the archive. The types of data (composition, rates, doping level, pressure, low-level parameters etc.) are user selected, as is the resolution of data collection, the time and Y-axis zoom and much more. Simple colour coding provides status/error identification at a glance. Click anywhere on a graph and the detailed data for the closest time sample is displayed.

EpiList "recipe" editor

    EpiCAD has three EpiList editors for growth recipe creation, inspection and editing. The above shows one of several views and illustrates the event paradigm. As well as events, repeat sequences, nested up to 9 levels, can be inserted, as can comments. As shown above, error conditions are automatically indicated.
   Dragging selects groups of steps permitting cut/copy/paste functionality thereby permitting complex structure to be defined quickly.

    Each event can be edited in detail by clicking on it to generate the EpiStep Editor:

    This provides complete control over everything occurring within the event, from thickness/time to ramps rates to growth rates and doping levels etc. Indeed, many parameters of a running growth can be edited without interrupting deposition.

Calibration Editor

    SOC requires that EpiCAD keeps complete and accurate maintenance of the relationships between growth parameter and low level value. For example, shown is the vapour pressure-based calibration relationship for an MBE Al source. EpiCAD provides a wide range of curve fits from any number of weighted data points. Knowledge of how to compensate for calibration drift makes for ease of "re-calibration" and ensures accurate operation of the source.