Initially developed for MBE applications, EpiSoft provides a unique approach to deposition process and overall system control. It is built around the principle of defining the growth process in terms of deposition events (growth rates, doping levels...) as opposed to low level parameters (temperature, voltage, flow rate...); we call this growth-oriented approach SOC (Structure-Oriented Control):
EpiSoft comprises 2 parts:
SOC is achieved through maintaining detailed "calibration" information (easily modified to reflect source digression) between the high and low level parameters within the EpiCAD software, which is only applied at the moment of communicating with the deposition system. The benefits of SOC extend well beyond the above:
EpiSoft has a 25 year history in controlling MBE and other deposition systems:
The EpiSoft system comprises 2 parts: the PC-based EpiCAD software and the SerialFrame hardware interface unit which connects the PC to the deposition system components.
The SerialFrame is a DIN-rail mounted "PLC" style interface with almost infinite expansion. It communicates with the PC using over the USB bus. A typical configuration comprises:
Most applications can be more than adequately controlled using the above configuration, but Serial8, SFDig10 and SFAn 10 units can be added as required.
All aspects of the SerialFrame, such as serial settings (baud rate, parity etc.), analogue ranges, comms watchdogs are user-selectable from within the EpiCAD software.
EpiCAD is an object-oriented environment based around user-definition of P-Loops (process loops), ports (communication ports), sensors (digital input events) and flags (digital output events). Each object has a range of user-defined attributes which allow it to simulate operation of a deposition component (such as substrate, source, dopant, interlock, shutter, valve...). EpiCAD contains a knowledge base as to how the different objects interact in a real deposition process.
In addition to SOC discussed above, EpiCAD provides a host of features including: