摘要:
An overhead gas distribution electrode forming at least a portion of the ceiling of a plasma reactor has a bottom surface facing a processing zone of the reactor. The electrode includes a gas supply manifold for receiving process gas at a supply pressure at a top portion of the electrode and plural pressure-dropping cylindrical orifices extending axially relative to the electrode from the gas supply manifold at one end of each the orifice. A radial gas distribution manifold within the electrode extends radially across the electrode. Plural axially extending high conductance gas flow passages couple the opposite ends of respective ones of the plural pressure-dropping orifices to the radial gas distribution manifold. Plural high conductance cylindrical gas outlet holes are formed in the plasma-facing bottom surface of the electrode and extend axially to the radial gas distribution manifold.
摘要:
A method of processing a workpiece in a chamber of a plasma reactor having a set of plural electromagnet coils includes selecting plural predetermined plasma density distributions relative to a workpiece surface, the predetermined plasma density distributions corresponding to different sets of D.C. currents in the coils, and flowing a process gas into the chamber and generating a plasma in the chamber. The method further includes switching plasma in the chamber between the predetermined plasma density distributions by switching D.C. currents through the coils between the different sets of D.C. currents.
摘要:
A method for processing a workpiece in a plasma reactor having a set of n coils includes constructing, for each one of the n coils, a set of plasma distributions for discrete values of coil current in a predetermined current range. The distributions are grouped, each group having one distribution for each of the n coils, and being a unique set of n distributions. A combined plasma distribution is computed from each group of distributions. The variance of each combined distribution is computed. The method further includes finding an optimum one of the combined distributions having an at least nearly minimum variance, and identifying the n coil currents associated with the optimum distribution. During plasma processing of the workpiece, currents through the coils are maintained at levels corresponding to the n coil currents associated with the one combined distribution.
摘要:
A plasma reactor for processing a workpiece, includes a vacuum chamber defined by a sidewall and ceiling, and a workpiece support pedestal having a workpiece support surface in the chamber and facing the ceiling and including a cathode electrode. An RF power generator is coupled to the cathode electrode. Plasma distribution is controlled by an external annular inner electromagnet in a first plane overlying the workpiece support surface, an external annular outer electromagnet in a second plane overlying the workpiece support surface and having a greater diameter than the inner electromagnet, and an external annular bottom electromagnet in a third plane underlying the workpiece support surface. D.C. current supplies are connected to respective ones of the inner, outer and bottom electromagnets.
摘要:
A plasma reactor having a reactor chamber and an electrostatic chuck with a surface for holding a workpiece inside the chamber includes a backside gas pressure source coupled to the electrostatic chuck for applying a thermally conductive gas under a selected pressure into a workpiece-surface interface formed whenever a workpiece is held on the surface and an evaporator inside the electrostatic chuck and a refrigeration loop having an expansion valve for controlling flow of coolant through the evaporator. The reactor further includes a temperature sensor in the electrostatic chuck and a memory storing a schedule of changes in RF power or wafer temperature. The reactor further includes a thermal model capable of simulating heat transfer between the evaporator and the surface based upon measurements from the temperature sensor, and a control processor coupled to the thermal model and to the memory and governing the backside gas pressure source in response to a prediction from the model of a change in the selected pressure that would compensate for the next scheduled change in RF power or implement the next scheduled change in wafer temperature.
摘要:
A plasma reactor for processing a workpiece includes a reactor chamber, an electrostatic chuck within the chamber having a top surface for supporting a workpiece and having indentations in the top surface that form enclosed gas flow channels whenever covered by a workpiece resting on the top surface. The reactor further includes thermal control apparatus thermally coupled to the electrostatic chuck, an RF plasma bias power generator coupled to apply RF power to the electrostatic chuck, a pressurized gas supply of a thermally conductive gas, a controllable gas valve coupling the pressurized gas supply to the indentations to facilitate filling the channels with the thermally conductive gas for heat transfer between a backside of a workpiece and the electrostatic chuck at a heat transfer rate that is a function of the pressure against the backside of the workpiece of the thermally conductive gas. The reactor further includes an agile workpiece temperature control loop including (a) a temperature probe in the electrostatic chuck, and (b) a backside gas pressure controller coupled to an output of the temperature probe and responsive to a specified desired temperature, the controller governing the gas valve in response to a difference between the output of the temperature probe and the desired temperature.
摘要:
A plasma reactor having a reactor chamber and an electrostatic chuck with a surface for holding a workpiece inside the chamber includes a backside gas pressure source coupled to the electrostatic chuck for applying a thermally conductive gas under a selected pressure into a workpiece-surface interface formed whenever a workpiece is held on the surface and an evaporator inside the electrostatic chuck and a refrigeration loop having an expansion valve for controlling flow of coolant through the evaporator. The reactor further includes a temperature sensor in the electrostatic chuck and a memory storing a schedule of changes in RF power or wafer temperature. The reactor further includes a thermal model capable of simulating heat transfer between the evaporator and the surface based upon measurements from the temperature sensor, and a control processor coupled to the thermal model and to the memory and governing the backside gas pressure source in response to a prediction from the model of a change in the selected pressure that would compensate for the next scheduled change in RF power or implement the next scheduled change in wafer temperature.
摘要:
An apparatus for generating uniform plasma across and beyond the peripheral edge of a substrate has a dielectric body with an upper electrode and an annular electrode embedded therein. The outer perimeter of the upper electrode overlaps the inner perimeter of the annular electrode. In one embodiment, the upper electrode and the annular electrode are electrically coupled by molybdenum vias. In one embodiment, the upper electrode is coupled to a DC power source to provide electrostatic force for chucking the substrate. In one embodiment, the upper electrode is coupled to an RF source for exciting one or more processing gasses into plasma for substrate processing.
摘要:
A plasma reactor for processing a workpiece includes a reactor chamber, an electrostatic chuck within the chamber for supporting a workpiece, an RF plasma bias power generator coupled to apply RF power to the electrostatic chuck and a refrigeration loop having an evaporator inside the electrostatic chuck with a refrigerant inlet and a refrigerant outlet. Preferably, the evaporator includes a meandering passageway distributed in a plane beneath a top surface of the electrostatic chuck. Preferably, refrigerant within the evaporator is apportioned between a vapor phase and a liquid phase. As a result, heat transfer between the electrostatic chuck and the refrigerant within the evaporator is a constant-temperature process. This feature improves uniformity of temperature distribution across a diameter of the electrostatic chuck.
摘要:
In a plasma reactor having an electrostatic chuck with an electrostatic chuck top surface for supporting a workpiece, thermal transfer medium flow channels in the interior of the electrostatic chuck, a method for controlling temperature of the workpiece during plasma processing includes circulating thermal transfer medium through the thermal transfer medium flow passages and supplying a thermally conductive gas between the workpiece and the electrostatic chuck top surface, and changing thermal transfer medium thermal conditions of thermal transfer medium flowing in the thermal transfer medium flow channels so as to change the temperature of the electrostatic chuck at a first rate limited by the thermal mass of the electrostatic chuck. The method further includes changing the backside gas pressure of the thermally conductive gas so as to change the temperature of the workpiece at a second rate faster than the first rate.