Varian Semiconductor Equipment Associates, Inc.

Applied Materials, Inc.

Alexandre Likhanskii

Frank Sinclair

Svetlana Radovanov

Jay Thomas Scheuer

Bon-Woong Koo

Peter F Kurunczi

Shengwu Chang

William Davis Lee

Costel Biloiu

Eric D Hermanson

Graham Wright

Robert C Lindberg

Anthony Renau

Alexander S Perel

Christopher W Campbell

Kevin R Anglin

Joseph C Olson

William M Holber

Daniel R Tieger

Tseh-Jen Hsieh

Ronald Johnson

You Chia Li

Jay S Johnson

Ryan Downey

John J Hautala

Christopher A Rowland

Antonella Cucchetti

Maureen Petterson

Nevin H Clay

Alan V Hayes

Dmitry Lubomirsky

Vikram Singh

Richard John Hertel

Kevin M Daniels

Piotr R Lubicki

Tyler Burton Rockwell

Philip Layne

Brant S Binns

Sudhakar Mahalingam

Wayne LeBlanc

Provided herein are approaches for providing a more uniform ion flux and ion angular distribution across a wafer to minimize etch yield loss resulting from etch profile variations. In some embodiments, a system may include a plasma source operable to generate a plasma within a plasma chamber enclosed by a chamber housing, wherein the plasma source comprises a plasma shaper extending into the plasma chamber from a wall of the chamber housing. The plasma shaper may include a shaper wall coupled to the wall of the chamber housing, and a shaper end wall connected to the shaper wall, the shaper end wall defining an indentation extending towards the wall of the chamber housing.

Plasma shaper to control ion flux distribution of plasma source

An ion source capable of extracting a ribbon ion beam with improved uniformity is disclosed. One of the walls of the ion source has a protrusion on its interior surface facing the chamber. The protrusion creates a loss area that serves as a sink for free electrons and ions. This causes a reduction in plasma density near the protrusion, and may improve the uniformity of the ribbon ion beam that is extracted from the ion source by modifying the beam current near the protrusion. The shape of the protrusion may be modified to achieve the desired uniformity. The protrusion may also be utilized with a cylindrical ion source. In certain embodiments, the protrusion is created by a plurality of mechanically adjustable protrusion elements.

Device to control uniformity of extracted ion beam

Single-slot tubular cathode

An ion extraction assembly for an ion source is provided. The ion extraction assembly may include a plurality of electrodes, wherein the plurality of electrodes comprises: a plasma-facing electrode, arranged for coupling to a plasma chamber; and a substrate-facing electrode, disposed outside of the plasma-facing electrode. The at least one electrode of the plurality of electrodes may include a grid structure, defining a plurality of holes, wherein the at least one electrode has a non-uniform thickness, wherein a first grid thickness in a middle region of the at least one electrode is different than a second grid thickness, in an outer region of the at least one electrode.

Ion extraction assembly having variable electrode thickness for beam uniformity control

An ion source having an extraction plate with a variable thickness is disclosed. The extraction plate has a protrusion on its interior or exterior surface proximate the extraction aperture. The protrusion increases the thickness of the extraction aperture in certain regions. This increases the loss area in those regions, which serves as a sink for ions and electrons. In this way, the plasma density is decreased more significantly in the regions where the extraction aperture has a greater thickness. The shape of the protrusion may be modified to achieve the desired plasma uniformity. Thus, it may be possible to create an extracted ion beam having a more uniform ion density. In some tests, the uniformity of the beam current along the width direction was improved by between 20% and 50%.

Variable thickness ion source extraction plate

An apparatus for directional processing is disclosed. The apparatus includes a workpiece support and an ion source, having a plurality of walls. An extraction aperture is disposed on at least one of the plurality of walls. In certain embodiments, the plurality of walls defines a hollow region. The hollow region is located above the portion of the workpiece that is being processed, allowing the etching byproducts can be evacuated without depositing on the ion source. The shape of the hollow region may be modified to further reduce the amount of deposition on the hollow ion source. Additionally, a pump may be disposed within or above the hollow region to facilitate the removal of the etching byproducts. In other embodiments, the extraction aperture of the ion source may be disposed at a corner of the plasma chamber.

Apparatus for directional processing

An ion source capable of extracting a ribbon ion beam with improved vertical angular uniformity is disclosed. The extraction plate and extraction optics are designed such that there is at least one non-uniform gap between adjacent components. A non-uniform gap may be effective in reducing angular spread non-uniformity of the extracted ribbon ion beam. Specifically, for a given gap in the Z direction, ions extracted from regions with lower plasma density may have more vertical angular spread. A larger gap in the Z direction between components in this region may make the vertical angular spread closer to the vertical angular spread of ions extracted from regions with higher plasma density. The non-uniform gap may be created by having an extraction plate that is flat or curved and electrodes that are flat, convex or concave. In certain embodiments, the non-uniform gap is located between the extraction plate and the suppression electrode.

Mismatched optics for angular control of extracted ion beam

An ion source including a chamber housing defining an ion source chamber and including an extraction plate on a front side thereof, the extraction plate having an extraction aperture formed therein, and a tubular cathode disposed within the ion source chamber and having an opening formed in a front half thereof nearest the extraction aperture, wherein a rear half of the tubular cathode furthest from the extraction aperture is closed.

Ion source with single-slot tubular cathode

An ion source having an electrically isolated extraction plate is disclosed. By isolating the extraction plate, a different voltage can be applied to the extraction plate than to the body of the arc chamber. By applying a more positive voltage to the extraction plate, more efficient ion source operation with higher plasma density can be achieved. In this mode the plasma potential is increased, and the electrostatic sheath reduces losses of electrons to the chamber walls. By applying a more negative voltage, an ion rich sheath adjacent to the extraction aperture can be created. In this mode, conditioning and cleaning of the extraction plate is achieved via ion bombardment. Further, in certain embodiments, the voltage applied to the extraction plate can be pulsed to allow ion extraction and cleaning to occur simultaneously.

Ion source with biased extraction plate

Provided herein are approaches for performing electrodynamic mass analysis with a radio frequency (RF) biased ion source to reduce ion beam energy spread. In some embodiments, a system may include an ion source including a power supply, the ion source operable to generate a plasma within a chamber housing, and an extraction power assembly including a first power supply and a second power supply electrically coupled with the chamber housing of the ion source, wherein the first power supply and the second power supply are operable to bias the chamber housing of the ion source with a time modulated voltage to extract an ion beam from the ion source. The system may further include an electrodynamic mass analysis (EDMA) assembly operable to receive the ion beam and perform mass analysis on the ion beam.

Electrodynamic mass analysis with RF biased ion source

A workpiece processing apparatus allowing independent control of the voltage applied to the shield ring and the workpiece is disclosed. The workpiece processing apparatus includes a platen. The platen includes a dielectric material on which a workpiece is disposed. A bias electrode is disposed beneath the dielectric material. A shield ring, which is constructed from a metal, ceramic, semiconductor or dielectric material, is arranged around the perimeter of the workpiece. A ring electrode is disposed beneath the shield ring. The ring electrode and the bias electrode may be separately powered. This allows the surface voltage of the shield ring to match that of the workpiece, which causes the plasma sheath to be flat. Additionally, the voltage applied to the shield ring may be made different from that of the workpiece to compensate for mismatches in geometries. This improves uniformity of incident angles along the outer edge of the workpiece.

Extreme edge uniformity control

Provided herein are approaches for in-situ plasma cleaning of ion beam optics. In one approach, a system includes a component (e.g., a beam-line component) of an ion implanter processing chamber. The system further includes a power supply for supplying a first voltage and first current to the component during a processing mode and a second voltage and second current to the component during a cleaning mode. The second voltage and current are applied to one or more conductive beam optics of the component, individually, to selectively generate plasma around one or more of the one or more conductive beam optics. The system may further include a flow controller for adjusting an injection rate of an etchant gas supplied to the beam-line component, and a vacuum pump for adjusting pressure of an environment of the beam-line component.

In-situ plasma cleaning of process chamber components

Provided herein are approaches for decreasing particle generation in an electrostatic lens. In some embodiments, an ion implantation system may include an electrostatic lens including an entrance for receiving an ion beam and an exit for delivering the ion beam towards a target, the electrostatic lens including a first terminal electrode, a first suppression electrode, and a first ground electrode disposed along a first side of an ion beamline, wherein the first ground electrode is grounded and positioned adjacent the exit. The electrostatic lens may further include a second terminal electrode, a second suppression electrode, and a second ground electrode disposed along a second side of the ion beamline, wherein the second ground electrode is grounded and positioned adjacent the exit. The implantation system may further include a power supply operable to supply a voltage and a current to the electrostatic lens for controlling the ion beam.

Electrostatic filter providing reduced particle generation

Shaped electrode

An ion source including a chamber housing defining an ion source chamber and including an extraction plate on a front side thereof, the extraction plate having an extraction aperture formed therein, and a tubular cathode disposed within the ion source chamber and having a slot formed in a front-facing semi-cylindrical portion thereof disposed in a confronting relationship with the extraction aperture, wherein a rear-facing semi-cylindrical portion of the tubular cathode directed away from the extraction aperture is closed.

Growing community of inventors

Malden, MA, United States of America

Alexandre Likhanskii