Specific Process Knowledge/Etch/DRIE-Pegasus/Parameters: Difference between revisions
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; Ramping (>) | ; Ramping (>) | ||
: Most process parameters on the DRIE-Pegasus may be ramped during a process step. The notation 140>90 in a pressure setting indicates that from the initial value of 140 mTorr the pressure is decreased linearly to an end value of 90 mTorr in the process step. The ramp rate (mTorr/min) therefore depends on the duration of the step. | : Most process parameters on the DRIE-Pegasus may be ramped during a process step. The notation 140>90 in a pressure setting indicates that from the initial value of 140 mTorr the pressure is decreased linearly to an end value of 90 mTorr in the process step. The ramp rate (mTorr/min) therefore depends on the duration of the step. | ||
; Forward power versus Load power | |||
: In order for the RF power supplied by the generators to be absorped by the plasma, the impedance of the plasma must match the impedance of the RF network. The impedance of the plasma relies on the gas composition, the pressure and the power and is therefore beyond direct control of the instrument. Between the RF generators and the coil, two capacitors called Load and Tune form a matching network that enables us to change the impedance of the RF network. The tuning of Load and Tune is usually done automatically by the software. If the two impedances are not similar, the RF power will be absorped by the RF network (RF generator and capacitors) instead of the plasma. The result is | |||