Sigma SQC-122c manual Chapter Operation

Chapter 2 Operation

While we’re on the Main Menu screen, and before starting the selected process, let’s cover the capabilities of the Next Menu screens.

Press Next Menu once to view the first Next Menu screen. This screen provides two important operator functions: Zero Thickness and Auto/Manual mode.

The Zero SoftKey can be used to zero the thickness reading at any time. It is not normally needed, since the SQC-122c automatically zeroes the thickness at the beginning of each layer. It is, however, useful when simulating a process and when operating in Manual mode.

The Auto/Manual key alternates between Automatic (PID) output control and Manual (user) output control. Auto/Manual indicates the process is in automatic control, and a key press will change to Manual control. Manual/Auto indicates Manual control; a key press changes to Automatic mode.

In Manual mode, the SQC-122c immediately starts the deposition phase for the current layer, whether the process was stopped or running. However, the PID loop is disabled and output power is controlled by the front panel control knob.

In Manual Mode, you will usually display the Rate Graph, then manually adjust the output power to achieve the desired deposition rate. It is easy to exceed a layer’s Final Thickness setpoint in Manual mode, so watch the Thickness reading carefully. Manual mode is particularly useful for determining preconditioning power levels, and loop gain (discussed later in Loop Tuning).

Moving from Manual mode to Auto mode places the SQC-122c into automatic (PID) control. The PID control loop will try to achieve rate setpoint, so there may be a rapid change in output power.

Press Next Menu again to view the second Next Menu screen.

Next Graph selects which of three available graphs is displayed. The Power Graph is useful during preconditioning. The Rate graph shows the response of the control loop to process changes, such as when moving from preconditioning to deposition. The Rate Deviation Graph shows the performance of the control system during deposition. The SQC-122c automatically displays the most useful graph for each phase of deposition.

Switch Displays toggles the process data display in the lower portion of the screen between two different process displays.

Sensor Info replaces the graph with a detailed display of sensor information.

2-12