Joseph T Olson

US Patent:

6403972, Jun 11, 2002

Filed:

Jul 8, 1999

Appl. No.:

09/349828

Inventors:

Antonella Cucchetti - Beverly MA
Joseph C. Olson - Beverly MA
Raymond L. Pelletier - Beverly MA
Keith Pierce - Ipswich MA
Anthony Renau - West Newbury MA
Donna Smatlak - Belmont MA

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 3730

US Classification:

25049221, 250398

Abstract:

An ion beam is sensed with a beam current sensor which has a sensing aperture that is smaller than a cross-sectional dimension of the ion beam at the beam current sensor. The sensed ion beam current is indicative of ion beam position relative to a desired ion beam path. The ion beam position may be adjusted if the sensed ion beam position differs from the desired ion beam path. One or more beam current sensors may be utilized in an ion implanter for calibration and/or alignment. The beam current sensor may be utilized to determine a relation between a characteristic of an ion beam, such as magnetic rigidity, and a parameter of a system element, such as magnetic field, required to direct the ion beam along a desired ion beam path.

US Patent:

6437350, Aug 20, 2002

Filed:

Aug 28, 2000

Appl. No.:

09/649183

Inventors:

Joseph C. Olson - Beverly MA
Anthony Renau - West Newbury MA

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 3708

US Classification:

25049221, 2504922, 250396 R, 2504923

Abstract:

Methods and apparatus for implanting ions in a workpiece, such as a semiconductor wafer, include generating an ion beam, measuring parallelism of the ion beam, adjusting the ion beam for a desired parallelism based on the measured parallelism, measuring a beam direction of the adjusted ion beam, orienting a workpiece at an implant angle referenced to the measured beam direction and performing an implant with the workpiece oriented at the implant angle referenced to the measured beam direction. The implant may be performed with a high degree of beam parallelism.

US Patent:

6573518, Jun 3, 2003

Filed:

Oct 30, 2000

Appl. No.:

09/699653

Inventors:

Anthony Renau - West Newbury MA
Joseph C. Olson - Beverly MA

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 37317

US Classification:

25049221, 25044211

Abstract:

A method for implanting ions into a workpiece, such as a semiconductor wafer, includes the steps of generating an ion beam, measuring an angle of non-parallelism of the ion beam, tilting the wafer at a first angle, performing a first implant at the first angle, tilting the wafer at a second angle, and performing a second implant at the second angle. The first and second angles are opposite in sign with respect to a reference direction and in magnitude are equal to or greater than the measured angle of non-parallelism. Preferably, the first and second implants are controlled to provide substantially equal ion doses in the workpiece.

US Patent:

6710359, Mar 23, 2004

Filed:

Mar 23, 2001

Appl. No.:

09/815484

Inventors:

Joseph C. Olson - Beverly MA
Rosario Mollica - Wilmington MA

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 3700

US Classification:

25049221, 2504921, 2504922, 25049222, 2504923, 250397, 250396, 250396 R, 250396 ML, 313360

Abstract:

Methods and apparatus are provided for adjusting the profile of a scanned ion beam. The spatial distribution of the unscanned ion beam is measured. The ion beam is scanned at an initial scan speed, and the beam profile of the scanned ion beam is measured. If the measured beam profile is not within specification, a scan speed correction that produces a desired profile correction is determined using a calculation which is based on the spatial distribution of the unscanned ion beam. The scan speed correction may be determined by convolving a candidate scan speed correction with the spatial distribution of the unscanned ion beam to produce a result and determining if the result is sufficiently close to the desired profile correction. A multi-dimensional search algorithm may be used to select the candidate scan speed correction. The ion beam is scanned at a corrected scan speed, which is based on the initial scan speed and the scan speed correction, to produce corrected beam profile.

US Patent:

6777686, Aug 17, 2004

Filed:

Apr 4, 2001

Appl. No.:

09/825901

Inventors:

Joseph C. Olson - Beverly MA
Daniel Distaso - Merrimac MA
Anthony Renau - West Newbury MA

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 3708

US Classification:

250423R, 250427, 31511181

Abstract:

An indirectly heated cathode ion source includes an extraction current sensor for sensing ion current extracted from the arc chamber and an ion source controller for controlling the filament power supply, the bias power supply and/or the arc power supply. The ion source controller may compare the sensed extraction current with a reference extraction current and determine an error value based on the difference between the sensed extraction current and the reference extraction current. The power supplies of the indirectly heated cathode ion source are controlled to minimize the error value, thus maintaining a substantially constant extraction current. The ion source controller utilizes a control algorithm, for example a closed feedback loop, to control the power supplies in response to the error value. In a first control algorithm, the bias current I supplied by the bias power supply is varied so as to control the extraction current I. Further according to the first control algorithm, the filament current I and the arc voltage V are maintained constant.

US Patent:

6791094, Sep 14, 2004

Filed:

Jun 6, 2000

Appl. No.:

09/588419

Inventors:

Joseph C. Olson - Beverly MA
Donna L. Smatlak - Belmont MA
Paul Daniel - Kittery Point ME

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 37317

US Classification:

250397, 250398, 250396 R, 250396 ML, 2504921, 2504922, 25049221

Abstract:

A method and apparatus for determining a direction or parallelism of a beam. The beam can be any type of beam, including uncharged or charged particle beams or electromagnetic radiation beams. The beam can have any desired size or shape and can be scanned or fixed in place. A direction or parallelism of the beam can be determined by adjusting an intensity profile of at least a portion of the beam at a first position. The adjusted intensity profile can be formed, for example, by blocking a portion of the beam at the first position. The adjusted intensity profile can be formed by a special purpose device, such as a mask, adjustable aperture, etc. , or by another device having a separate purpose. For example, a beam modifier used to form the adjusted intensity profile can be a detector used to determine a measure of uniformity of the beam. One or more detected intensity profiles downstream of the first position can be identified and the relative positions of where the adjusted intensity profile is formed and where the intensity profile(s) are detected relative to a reference direction can be used to determine a direction or parallelism of the beam.

US Patent:

6984831, Jan 10, 2006

Filed:

Mar 5, 2004

Appl. No.:

10/794850

Inventors:

Russell J. Low - Rowley MA, US
Joseph C. Olson - Beverly MA, US
Curt D. Bergeron - Danvers MA, US
Eric R. Cobb - Danvers MA, US
Jeffrey A. Burgess - Manchester MA, US

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 37/08

US Classification:

25049221, 250423 R, 250427, 31511181, 313270, 313310

Abstract:

A cathode system having a cathode element configured to extend through an aperture in a wall of an arc chamber of an ion implanter system. A gas flow through a spacing between the cathode element and the aperture is restricted by a restriction member. A method of ionizing a source gas and a cathode element incorporating the restriction member are also provided.

US Patent:

7045799, May 16, 2006

Filed:

Nov 19, 2004

Appl. No.:

10/993346

Inventors:

Shengwu Chang - South Hamilton MA, US
Joseph C. Olson - Beverly MA, US
Donald Anderson - Rowley MA, US
Daniel McGillicuddy - Meford MA, US

Assignee:

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

International Classification:

H01J 37/317

US Classification:

2504922, 25049221, 2504923, 250281

Abstract:

A method and apparatus for weakening a strong focus effect of an acceleration-deceleration column of an ion implanter during a deceleration mode are disclosed. The apparatus includes a tube lens surrounding the ion beam adjacent to a deceleration lens of the acceleration-deceleration column. The tube lens causes a defocusing of the ion beam at the entrance of the tube lens, which reduces the ion dispersion problem generated by the column. The invention also includes an accel-decel column and ion implanter incorporating the tube lens. An additional deceleration-suppression electrode may also be added subsequent to the tube lens for confining electrons within the tube lens.