Energy conservation mode signalling standardization

Energy saving operational modes (a.k.a. Green or Idle Mode) has the potential to help the semiconductor industry reduce utility consumption in the manufacture of semiconductor wafers at times when wafers are not being processed. This functionality has been available for many years in a range of support equipment, such as vacuum pumps, where the rotational speed (and therefore power consumption) can be lowered, and gas abatement systems where the fuel gas or electricity can be minimized. Such reductions will also have the beneficial effect of lowering the emissions of CO2. Unfortunately it has been extremely difficult to access these savings in practice due to the lack of appropriate standard signals and protocols. A working group was initiated by ISMI, a subsidiary of SEMATECH in 2009, which subsequently became a SEMI Standards Task Force, to address the standardization of the behavior and communication of energy conservation modes between the factory, semiconductor equipment and subsystems. The task was split into 2 phases because of the wide scope of the task; the first phase addressed the factory and semiconductor equipment communications, culminating with the publication of SEMI standard E167, published last year. This, however, only covers part of the story, so the second phase has progressed this year to address the issue of semiconductor equipment to support equipment or subsystems (such as pumps and abatement, where the majority of the savings can actually be realized) communications. Progress to date will be reviewed, including why the process tool is the gatekeeper for passing on energy saving mode commands, the proposed state machine behavior, command, signaling, and the intended route for implementation.