Bias supply with a single controlled switch
Bias supplies, plasma processing systems, and associated methods are disclosed. One bias supply comprises a first inductor coupled between a first node of a switch and an output node where a first node of a second inductor is coupled to one of the output node or the first node of the switch. A voltage source is coupled between a second node of the switch and a second node of the second inductor. A connection is made between the return node and one of the second node of the switch and the second node of the second inductor. The bias supply also comprises a controller configured to cause an application of the periodic voltage between the output node and the return node by repeatedly closing the switch so current through the switch completes a full cycle.
1. A bias supply to apply a periodic voltage comprising:
an output node;
a return node;
a switch;
a first inductor coupled between a first node of the switch and the output node;
a first node of a second inductor coupled to one of the output node or the first node of the switch;
a voltage source coupled between a second node of the switch and a second node of the second inductor;
a connection between the return node and one of the second node of the switch and the second node of the second inductor; and
a controller configured to cause an application of the periodic voltage between the output node and the return node by repeatedly closing the switch for a time just long enough for current through the switch to complete a full cycle from zero to a peak value, back to zero, to a peak value in an opposite direction and back to zero.
2. The bias supply of claim 1 , wherein the controller is configured to adjust a voltage of the voltage source and a time between the repeated switch closures to achieve a desired periodic voltage.
3. The bias supply of claim 1 , wherein the controller includes at least one of a processor or a field programmable gate array and the controller includes non-transitory computer-readable medium comprising instructions stored thereon, for execution by the processor, or for configuring the field programmable gate array, to control operation of the switch.