Process for depositing a layer of material on a substrate
View Patent ↗An electroplating system ( 30 ) and process makes electrical current density across a semiconductor device substrate ( 20 ) surface more uniform during plating to allow for a more uniform or tailored deposition of a conductive material. The electrical current density modifiers ( 364 and 37 ) reduce the electrical current density near the edge of the substrate ( 20 ). By reducing the current density near the edge of the substrate ( 20 ), the plating becomes more uniform or can be tailored so that slightly more material is plated near the center of the substrate ( 20 ). The system can also be modified so that the material that plates on electrical current density modifier portions ( 364 ) of structures ( 36 ) can be removed without having to disassemble any portion of the head ( 35 ) or otherwise remove the structures ( 36 ) from the system. This in-situ cleaning reduces the amount of equipment downtime, increases equipment lifetime, and reduces particle counts.
1. A process for depositing a layer of material over a semiconductor substrate comprising the steps of:
placing the semiconductor substrate into a plating system, wherein the plating system includes:
an anode;
a cathode that includes clamp structures for holding a semiconductor substrate;
an ionic liquid within a cup, wherein the ionic liquid contacts the anode, the semiconductor substrate, and the clamp structures;
depositing a layer of plating material onto the semiconductor substrate and the clamp structures;
removing the semiconducter substrate from the plating system; and
subsequent to removal of the semiconductor substrate from the plating system and prior to plating an additional semiconductor substrate, removing at least a portion of the plating material deposited on the clamping structures by in-situ cleaning, wherein in-situ cleaning includes biasing the cathode at a more positive potential than the anode in the absence of the semiconductor substrate.
2. A process for depositing a layer of material over a semiconductor substrate comprising the steps of:
placing the semiconductor substrate into a plating system, wherein the plating system includes:
an anode;
a cathode that includes clamp structures for holding a semiconductor substrate;
an ionic liquid within a cup, wherein the ionic liquid contacts the anode, the semiconductor substrate, and the clamp structures;
a diffuser located within the cup and positioned between the anode and the cathode; and
an electrical current density modifier being located with in the cup and positioned between the diffuser and a top of the cup;
depositing a layer of plating material onto the semiconductor substrate and the clamp structures;
removing the semiconductor substrate from the plating system; and
subsequent to removal of the semiconductor substrate from the plating system and prior to plating an additional semiconductor substrate, removing at least a portion of the plating material deposited on the clamping structures by in-situ cleaning, wherein in-situ cleaning includes biasing the cathode at a more positive potential than the electrical current density modifier, in the absence of the semiconductor substrate.
3. The process of claim 2 , further comprising electrically floating the anode during removing at least a portion of the plating material deposited on the clamping structures.
4. The process of claim 2 , further comprising not electrically floating the anode during removing at least a portion of the plating material deposited on the clamping structures.
5. The process of claim 4 , further comprising conditioning the anode prior to processing additional substrates within the plating system.