Lsi Logic Corporation

Lsi Logic Corportion

Roger Patrick

Philippe Schoenborn

Frank Bose

Nicholas F Pasch

Mark A Franklin

Frank A Bose

Harry Toda

An apparatus for producing a plasma suitable for semiconductor processing at pressures in the low millitorr range. The apparatus includes a vacuum chamber with a dielectric window, a generally planar coil disposed adjacent the window outside the chamber and coupled to an appropriate power source, and a plasma initiator disposed within the chamber. Once the plasma is initiated, the planar coil sustains the plasma by inductive power coupling. In one embodiment the plasma initiator is a secondary electrode disposed within the chamber and coupled to a second RF power source. In an alternative embodiment both the secondary electrode and a target pedestal are coupled to the secondary RF power source through a power splitter. In an alternative embodiment, the plasma initiator is used to ionize a portion of the process gas and provide a plasma that may then inductively couple with the planar coil. Initial ionization of the process gas may be achieved by use of an ultraviolet light source, an ultraviolet laser, a high voltage power source such as a tesla coil, or an electrical arc forming device such as a spark plug.

Plasma initiating assembly

Method for igniting low pressure inductively coupled plasma

The present invention relates to a method for generating a low pressure plasma circulating in a planar direction within a process enclosure. The invention generates plasma having substantially uniform density characteristics across a planar axis. The invention achieves improved uniformity of the plasma density by delivering more radio frequency power toward the periphery of the circulating plasma than toward the center of the plasma. Increasing the periphery power to the circulating plasma compensates for increased plasma losses due to interaction with the side walls of the process containment enclosure.

Coil configurations for improved uniformity in inductively coupled

The present invention relates to a system and method for control and delivery of radio frequency power in plasma process systems. The present invention monitors the power, voltage, current, phase, impedance, harmonic content and direct current bias of the radio frequency energy being delivered to the plasma chamber. In addition, the plasma mode of operation may be controlled by creating either a capacitively or inductively biased radio frequency source impedance. A radio frequency circulator prevents reflected power from the plasma chamber electrode to damage the power source and it further dissipates the reflected power in a termination resistor. The termination resistor connected to the circulator also effectively terminates harmonic energy caused by the plasma non-linearities. Multiple plasma chamber electrodes and radio frequency power sources may be similarly controlled.

Power control and delivery in plasma processing equipment

Via filling is enhanced by the techniques of 1) providing pillars immediately underneath semiconductor features, such as metal layer contacts (inter-connection points), and 2) polishing off excess via-filling material so that the via-filling plug is flush with the topmost insulating layer. The pillars are provided under every feature over which a via will be formed, so that an insulating layer surrounding the via will be thinner at the location of the feature. If necessary, polishing is continued to thin the insulating layer so that the plugs in initially selectively under-filled vias are made flush with the insulating layer. Method and apparatus are disclosed.

Techniques for via formation and filling

Dynamic control and delivery of radio frequency power in plasma process systems is utilized to enhance the repeatability and uniformity of the process plasma. Power, voltage, current, phase, impedance, harmonic content and direct current bias of the radio frequency energy being delivered to the plasma chamber may be monitored at the plasma chamber and used to control or characterize the plasma load. Dynamic pro-active control of the characteristics of the radio frequency power to the plasma chamber electrode during the formation of the plasma enhances the uniformity of the plasma for more exact and controllable processing of the work pieces.

Uniform and repeatable plasma processing

An apparatus for producing a plasma suitable for semiconductor processing at pressures in the low millitorr range. The apparatus includes a vacuum chamber with a dielectric window, a generally planar coil disposed adjacent the window outside the chamber and coupled to an appropriate power source, and a plasma initiator disposed within the chamber. Once the plasma is initiated, the planar coil sustains the plasma by inductive power coupling. In one embodiment the plasma initiator is a secondary electrode disposed within the chamber and coupled to a second RF power source. In an alternative embodiment both the secondary electrode and a target pedestal are coupled to the secondary RE power source through a power splitter. In an alternative embodiment, the plasma initiator is used to ionize a portion of the process gas and provide a plasma that may then inductively couple with the planar coil. Initial ionization of the process gas may be achieved by use of an ultraviolet light source, an ultraviolet laser, a high voltage power source such as a tesla coil, or an electrical arc forming device such as a spark plug.

Apparatus for igniting low pressure inductively coupled plasma

The present invention relates to a system and method for detecting the end-point of a layer being removed from a semiconductor wafer by a plasma etching system. The invention determines end-point by referencing first and second positions of matching components of a matching network between a radio frequency source and the plasma etching system chamber. Comparison of a first position representative of chamber load impedance before end-point, and a second position representative of a change in chamber load impedance is utilized to determine end point.

End-point detection in plasma etching by monitoring radio frequency

The present invention relates to an apparatus for generating a low pressure plasma circulating in a planar direction within a process enclosure. The invention generates plasma having substantially uniform density characteristics across a planar axis. The invention achieves improved uniformity of the plasma density by delivering more radio frequency power toward the periphery of the circulating plasma than toward the center of the plasma. Increasing the periphery power to the circulating plasma compensates for increased plasma losses due to interaction with the side walls of the process containment enclosure.

A method for forming uniformly sized features, such as polysilicon lines or gates, or such as conductive lines, on a semi conductor wafer having a planar upper surface is described which minimizes variations in the critical dimensions of the features. The technique allows a substantially uniform overlying layer, such as photoresist, to be formed above the layer intended to contain the features. The method can be applied to forming isolation trenches around active areas on the semiconductor wafer, overfilling the trenches with an insulating material (e.g., oxide), polishing back the oxide to a planar surface, depositing a planar layer of a conductive material (e.g., poly), and depositing a planar layer of a photoresist. The planar layer of photoresist, being deposited over a planar layer of conductive material has substantially uniform thickness and correspondingly uniform reflectivity. As a result, conductive lines formed by photolithographic processing of the underlying conductive material are substantially uniform in both width and thickness.

Formation of uniform dimension conductive lines on a semiconductor wafer

A glass passivation layer is deposited, densified and polished. Thereby an underlying wafer containing substantially defined devices is exposed to a temperature cycle that is sufficient for densification of the glass, and no more. Reflow and its attendant additional temperature cycle are thereby avoided, allowing for smaller, faster devices to be fabricated. Increased control over the ultimate thickness of the glass layer is also provided.

Densifying and polishing glass layers

A method for forming a multilayer integrated circuit is described wherein the resultant top surface thereof is substantially planar. The method involves first forming a layer of connecting metallization on integrated circuit components formed in a conventional manner. Then a first layer of dielectric is formed on the metallization layer. Next a second dielectric layer is formed on the first dielectric layer. Via areas are then formed by etching the first and second dielectric layers in order to expose selected areas of the first metallization layer, and filled with metal to form vias. A layer of photoresist is deposited on all surfaces. Lastly, the surface is etched using an etchant that etches dielectric, metal and photoresist at substantially the same rate such that said vias are exposed and a planar top surface produced.

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Santa Clara, CA, United States of America

Roger Patrick