SECS / GEM is a semiconductor and photovoltaic industries such as communications infrastructure used, were set up EAP, MES and other management systems on top of this.
SECS / GEM will have to use a lot of attention to content, such as the stability of the process of communication, and communication security issues. Authenticates the communications parties, as well as the back door to avoid exposure to information issues.
Stable and secure software modules, and the user terminal through the rigors of the factory, many of whom JECT, Cree, OSRAM, etc., stability, high efficiency requirements of the SECS / GEM also brings excellent experience equipment to allow customers satisfied engineers, will also allow customers to more high-level recognition device.
In many equipment control applications there is a need for a GEM host to modify one or a small set of
process parameters associated with a recipe. The number of parameters modified, frequency of modification (e.g.,
wafer-to-wafer, batch-to-batch, etc.), range of modification, etc., is largely a function of the equipment control
application. Utilizing GEM, at least two methods are envisioned for modifying process parameters on a tool. With the
first method, ‘Equipment Constants’ can be used to relate process parameters of the updated recipe. Equipment
Constants can also be used in a mode where they relate suggested modifications to process parameters from the stored
recipe; that is, the constants contain only the ± differential from a nominal value. The former mode is preferred because
it better ensures data integrity between the controller and tool. With the second method the entire recipe could be
downloaded, but this results in an enormous amount of communication overhead. Note that, in all cases, the Equipment
Constants do not replace the process parameters inside a recipe, but are associated with (e.g., linked to) these
parameters to relate modifications. The remainder of this application note provides a description of how process
parameter modification can be implemented using existing GEM capabilities. The method may be used in a GEM
compliant system provided that the specific GEM capabilities described are supported.
The equipment constants should represent the actual values of the process parameters with which they are
associated. Depending on the equipment operation and control application, the equipment constant could represent
the actual value of a process parameter at a recipe step, or over the entire recipe. The equipment constants could also
be utilized to represent the differentials of process parameters from nominal values. However it is important to note
that, when using differential values to relate process parameter modifications, any loss of synchronization between
equipment and host could result in an incorrect assessment of the value of a process setpoint by the host. Note also
that, upon system startup, and whenever the appropriate process parameters are modified, the equipment constants
should also be modified as necessary to always reflect the (absolute or relative) values of the associated process
parameters.
