摘要:
A method of etching a dielectric layer on a substrate with high etching selectivity, low etch rate microloading, and high etch rates is described. In the method, the substrate is placed in a process zone, and a plasma is formed from process gas introduced into the process zone. The process gas comprises (i) fluorocarbon gas for etching the dielectric layer and for forming passivating deposits on the substrate, (ii) carbon-oxygen gas for enhancing formation of the passivating deposits, and (iii) nitrogen-containing gas for etching the passivating deposits on the substrate. The volumetric flow ratio of fluorocarbon:carbon-oxygen:nitrogen-containing gas is selected to provide a dielectric to resist etching selectivity ratio of at least about 10:1, an etch rate microloading of
摘要:
The present invention is embodied in a plasma reactor for processing a workpiece such as a semiconductor wafer having an axis of symmetry, the reactor including a reactor chamber with a ceiling, a pedestal for supporting the workpiece within the chamber under the ceiling, a processing gas supply inlet into the chamber, an RF plasma power source coupled to the pedestal, and a magnetic field source near the ceiling providing a radially symmetrical magnetic field relative to the axis of symmetry within a portion of the chamber near the ceiling. The magnetic field source can include an electromagnet or plural magnets disposed over the ceiling in a radially symmetrical fashion with respect to the axis of symmetry. The plural magnets may be permanent magnets or electromagnets. The radially symmetrical magnetic field penetrates from the ceiling into the chamber to a shallow depth, and the height of the ceiling above the workpiece exceeds the depth.
摘要:
A plasma chamber having a magnet which produces a magnetic field such that, within a region parallel to and adjacent to the workpiece, the direction of the magnetic field is approximately the vector cross product of (i) the gradient of the magnitude of the magnetic field, and (ii) a vector extending perpendicularly from the workpiece surface toward the plasma. Alternatively, the plasma chamber includes a north magnetic pole and a south magnetic pole located at distinct azimuths around the periphery of the workpiece. The azimuth of the south magnetic pole relative to the north magnetic pole is clockwise around the central axis, and each magnetic pole faces a direction which is more toward than away from a central axis of the workpiece area. An additional aspect of the invention is a plasma chamber having a rotating magnetic field produced by electromagnets spaced around the periphery of the workpiece which receive successive fixed amounts of electrical current during successive time intervals. During each transition between the time intervals, the current supplied to each electromagnet is changed relatively slowly or relatively quickly according to whether the current change includes a change in polarity.
摘要:
Apparatus for retaining a wafer having improved wafer and chuck edge protection, contains an protection ring that circumscribes a pedestal and is biased to be in constant contact with the backside of the wafer. A biasing element uniformly biases the protection ring into contact with the circumferential edge of the wafer. The protection ring has an annular plan form that circumscribes an electrostatic chuck for retaining the wafer in a stationery position. Vertical travel of the ring is restricted by a hard stop that is formed by a portion of a focus ring which overhangs the protection ring. After a wafer is placed upon the chuck and the chucking force enabled, the chucking force easily overcomes the bias force upon the protection ring and the wafer rests upon the chuck support surface. The protection ring contacts the backside of the wafer to ensure that pedestal and electrostatic chuck are not exposed to the plasma and, when a silicon protection ring is used, the effective area of the wafer is extended beyond the physical dimensions of the wafer to facilitate a more uniform plasma distribution over the wafer.
摘要:
A magnetic field enhanced plasma etch reactor system for generating a radially-directed magnetic field within a reaction chamber. The reactor system comprises a reaction chamber for containing a plasma and a plurality of electromagnetic coils disposed about a reaction region within the reaction chamber. When each coil is driven with a current of similar magnitude, the electromagnetic coils produce a radially-directed magnetic field within the reaction chamber. The radially-directed magnetic field uniformly distributes the plasma throughout a bulk plasma region. Consequently, a substrate that is etched by such a uniform plasma has an improved uniformity in the etch pattern on the substrate.
摘要:
A plasma reactor embodying the invention includes a wafer support and a chamber enclosure member having an interior surface generally facing the wafer support. At least one miniature gas distribution plate for introducing a process gas into the reactor is supported on the chamber enclosure member and has an outlet surface which is a fraction of the area of the interior surface of said wafer support. A coolant system maintains the chamber enclosure member at a low temperature, and the miniature gas distribution plate is at least partially thermally insulated from the chamber enclosure member so that it is maintained at a higher temperature by plasma heating.
摘要:
An apparatus and method for scavenging etchant species from a plasma formed of etchant gas prior to the etchant gas entering a primary processing chamber of a plasma reactor. There is at least one scavenging chamber, each of which is connected at an inlet thereof to an etchant gas source and at an outlet thereof to a gas distribution device of the primary processing chamber. Each scavenging chamber has a radiation applicator that irradiates the interior of the scavenging chamber and creates a plasma therein from etchant gas flowing through the chamber from the etchant gas source to the gas distribution apparatus of the primary processing chamber. The applicator uses either an inductive discharge, capacitive discharge, direct current (DC) discharge or microwave discharge to irradiate the interior of the scavenging chamber and ignite the plasma. An etchant species scavenging source is also disposed within the scavenging chamber. This source provides scavenging material that interacts with the plasma to scavenge etchant species created by the dissociation of the etchant gas in the plasma and form etch by-products comprised of substances from both the etchant species and the scavenging source. The scavenging chambers can be employed, as is or in a modified form, as excitation chambers to excite gases at optimal conditions and feed the modified gases into the primary chamber. The scavenging chamber is modified by removing its scavenging source if this source would adversely interact with the gas being excited.
摘要:
A method of etching a dielectric layer (20) on a substrate (25) with high etching selectivity, low etch rate microloading, and high etch rates is described. In the method, a substrate (25) having a dielectric layer (20) with resist material thereon, is placed in a process zone (55), and a process gas is introduced into the process zone (55). The process gas comprises (i) fluorohydrocarbon gas for forming fluorine-containing etchant species capable of etching the dielectric layer (20), (ii) NH.sub.3 -generating gas having a liquefaction temperature L.sub.T in a range of temperatures .DELTA.T of from about -60.degree. C. to about 20.degree. C., and (iii) carbon-oxygen gas. The temperature of substrate (25) is maintained within about .+-.50.degree. C. of the liquefaction temperature L.sub.T of the NH.sub.3 -generating gas. A plasma is formed from the process gas to etch the dielectric layer (20) on the substrate (25). Preferably, the volumetric flow ratio of fluorohydrocarbon:NH.sub.3 -generating gas is from about 2.5:1 to about 7:1.
摘要:
A plasma reactor has plural dielectric gas injection tubes extending from a gas injection source and through a microwave guide and into the top of the reactor chamber. The semiconductor wafer rests near the bottom of the chamber on a wafer pedestal connected to a bias RF power source which is controlled independently of the microwave source coupled to the microwave guide. The microwaves from the waveguide ignite and maintain a plasma in each of the tubes. Gas flow through the tubes carries the plasmas in all the tubes into the chamber and into contact with the wafer surface.
摘要:
A plasma reactor has plural dielectric gas injection tubes extending from a gas injection source and through a microwave guide and into the top of the reactor chamber. The semiconductor wafer rests near the bottom of the chamber on a wafer pedestal connected to a bias RF power source which is controlled independently of the microwave source coupled to the microwave guide. The microwaves from the waveguide ignite and maintain a plasma in each of the tubes. Gas flow through the tubes carries the plasmas in all the tubes into the chamber and into contact with the wafer surface.