Specific Process Knowledge/Etch/DRIE-Pegasus/picoscope: Difference between revisions
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Above to the left, one can see the multiplexing of the Bosch process by alternation of the gas flows of | Above to the left, one can see the multiplexing of the Bosch process by alternation of the gas flows of | ||
<span style="color:#FFFFFF; background:blue">SF<sub>6</sub></span> (that has flow initially at 350 sccm in the break for the first 1.5 second then 550 sccm for 5.5 seconds in the main etch phase) and <span style="background:red">C<sub>4</sub>F<sub>8</sub></span> (at 200 sccm in the dep phase) according to the process recipe table above. Below, the <span style="background:lime">Pressure</span> alternates between 25 mtorr (dep and break) and 150 mtorr (main). The <span style="background:yellow">Platen Electrode DC Bias</span> (the electrostatic potential difference between the plasma and the wafer electrode that drives the ion bombardment in the etch process) is generated by the <span style="color:#FFFFFF; background:purple">Platen Power</span> at 140 W in the break and 45 W in the main etch. Below this, the [[Specific Process Knowledge/Etch/DRIE-Pegasus/System-description#RF_matching_in_general|<span style="background:silver">Reflected Platen Power</span>]] is not zero. The <span style="background:aqua">Coil Power</span> is 2800 W (etch) and 2000W (dep) with the | <span style="color:#FFFFFF; background:blue">SF<sub>6</sub></span> (that has flow initially at 350 sccm in the break for the first 1.5 second then 550 sccm for 5.5 seconds in the main etch phase) and <span style="background:red">C<sub>4</sub>F<sub>8</sub></span> (at 200 sccm in the dep phase) according to the process recipe table above. Below, the <span style="background:lime">Pressure</span> alternates between 25 mtorr (dep and break) and 150 mtorr (main). The <span style="background:yellow">Platen Electrode DC Bias</span> (the electrostatic potential difference between the plasma and the wafer electrode that drives the ion bombardment in the etch process) is generated by the <span style="color:#FFFFFF; background:purple">Platen Power</span> at 140 W in the break and 45 W in the main etch. Below this, the [[Specific Process Knowledge/Etch/DRIE-Pegasus/System-description#RF_matching_in_general|<span style="background:silver">Reflected Platen Power</span>]] is not zero. The <span style="background:aqua">Coil Power</span> is 2800 W (etch) and 2000W (dep) with the | ||
[[Specific Process Knowledge/Etch/DRIE-Pegasus/System-description#RF_matching_in_general|<span style="background:fuchsia">Reflected Coil Power</span>]] below. The spikes in Coil Power at every point where the Reflected is not zero indicates that the Coil Power is running in Load mode where the power lost as reflected power is compensated for by increasing the input power. | [[Specific Process Knowledge/Etch/DRIE-Pegasus/System-description#RF_matching_in_general|<span style="background:fuchsia">Reflected Coil Power</span>]] below. The spikes in Coil Power at every point where the Reflected is not zero indicates that the Coil Power is running in Load mode (as opposed to Forward mode) where the power lost as reflected power is compensated for by increasing the input power. | ||
Process A has 4 second dep phase and 7 second (1.5 second break and 5.5 second main) and the SPTS Pro software samples the process parameters every 0.5 second. This produces plots as seen above where all measurements have markers. One can ask the questions: | |||
# What happens if the cycle duration is lowered in order produce smaller scallops? | |||
# If | |||
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Image:PrD4 pico.png | Right: Recorded with the Picoscope | Image:PrD4 pico.png | Right: Recorded with the Picoscope | ||
</gallery> | </gallery> | ||
zx | |||