Daniel S Hoffman

US Patent:

6667577, Dec 23, 2003

Filed:

Dec 18, 2001

Appl. No.:

10/025408

Inventors:

Steven Shannon - San Mateo CA
Daniel Hoffman - Saratoga CA
Chunshi Cui - San Jose CA
Yan Ye - Saratoga CA
Gerardo Delgadino - Santa Clara CA
Shiang-Bau Wang - Hsinchu, TW
Robert B. Hagen - Newark CA
Matthew L Miller - Newark CA
Stephen Thai - Milpitas CA

Assignee:

Applied Materials, Inc - Santa Clara CA

International Classification:

H01J 724

US Classification:

31511121, 31511181, 118723 I

Abstract:

An RF power applicator of the reactor includes inner and outer conductive radial spokes. The set of inner conductive spokes extends radially outwardly from and is electrically connected to the conductive post toward the conductive side wall. The set of outer conductive spokes extends radially inwardly toward the conductive post from and is electrically connected to the conductive side wall. In this way, the inner and outer sets of conductive spokes are electrically connected together, the combination of the inner and outer set of spokes with the conductive enclosure having a fundamental resonant frequency inversely proportional to the height of the conductive enclosure and the lengths of the inner and outer set of conductive spokes. An RF source power generator is coupled across the RF power applicator and has an RF frequency corresponding to the fundamental resonant frequency.

US Patent:

6879870, Apr 12, 2005

Filed:

Apr 16, 2002

Appl. No.:

10/124191

Inventors:

Steven C. Shannon - San Mateo CA, US
Daniel J. Hoffman - Saratoga CA, US
Michael Barnes - San Ramon CA, US
Lee LaBlanc - Sunnyvale CA, US

International Classification:

G01F019/00

US Classification:

700121

Abstract:

A method and apparatus for routing harmonic energy within a plasma to ground in a plasma enhanced semiconductor wafer processing reactor. A model of the chamber is used to determine the pathway for RF power and the harmonic energy of that RF power through the chamber. From this model, the placement and design of a harmonic routing circuit is determined to shunt the harmonic energy to ground.

US Patent:

6900596, May 31, 2005

Filed:

Sep 4, 2002

Appl. No.:

10/235988

Inventors:

Jang Gyoo Yang - Sunnyvale CA, US
Daniel J. Hoffman - Saratoga CA, US
James D. Carducci - Sunnyvale CA, US
Melissa Hagen - Newark CA, US
Matthew L. Miller - Newark CA, US
Kang-Lie Chiang - San Jose CA, US
Gerardo A. Delgadino - Santa Clara CA, US

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H01J007/24

US Classification:

31511121, 31511151, 31511141, 31511181, 118723 I

Abstract:

A plasma reactor for processing a semiconductor wafer includes a side wall and an overhead ceiling defining a chamber, a workpiece support cathode within the chamber having a working surface facing the ceiling for supporting a semiconductor workpiece, process gas inlets for introducing a process gas into the chamber and an RF bias power generator having a bias power frequency. There is a bias power feed point at the working surface and an RF conductor is connected between the RF bias power generator and the bias power feed point at the working surface. A dielectric sleeve surrounds a portion of the RF conductor, the sleeve having an axial length along the RF conductor, a dielectric constant and an axial location along the RF conductor, the length, dielectric constant and location of the sleeve being such that the sleeve provides a reactance that enhances plasma ion density uniformity over the working surface. In accordance with a further aspect, the reactor can include an annular RF coupling ring having an inner diameter corresponding generally to a periphery of the workpiece, the RF coupling ring extending a sufficient portion of a distance between the working surface and the overhead electrode to enhance plasma ion density near a periphery of the workpiece.

US Patent:

7286948, Oct 23, 2007

Filed:

Jun 16, 2006

Appl. No.:

11/424705

Inventors:

Steven C. Shannon - San Mateo CA, US
Daniel J. Hoffman - Saratoga CA, US
Jeremiah T. P. Pender - San Jose CA, US
Tarreg Mawari - Manassas VA, US

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

G01R 23/16

US Classification:

702 76, 702118, 118712, 15634524, 15634528, 216 59, 216 61, 700108, 700121, 438 9

Abstract:

Methods for determining characteristics of a plasma are provided. In one embodiment, a method for determining characteristics of a plasma includes obtaining metrics of current and voltage information for first and second waveforms coupled to a plasma at different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform. In another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, and determining at least one characteristic of a plasma using model. In yet another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, measuring current and voltage for waveforms coupled to the plasma and having at least two different frequencies, and determining ion mass of a plasma from model and the measured current and voltage of the waveforms.

US Patent:

7359177, Apr 15, 2008

Filed:

May 10, 2005

Appl. No.:

11/127036

Inventors:

Jang Gyoo Yang - Sunnyvale CA, US
Daniel J. Hoffman - Saratoga CA, US
Steven C. Shannon - San Mateo CA, US
Douglas H. Burns - Saratoga CA, US
Wonseok Lee - Pleasanton CA, US
Kwang-Soo Kim - Santa Clara CA, US

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H01L 21/683
H01T 23/00
G01L 21/30
G01R 31/00
H01J 7/24
H05B 31/26
C23F 1/00
H01L 21/306

US Classification:

361234, 216 59, 31511121, 15634528

Abstract:

A plasma reactor has a dual frequency plasma RF bias power supply furnishing RF bias power comprising first and second frequency components, f(), f(), respectively, and an RF power path having an input end coupled to the plasma RF bias power supply and an output end coupled to the wafer support pedestal, and sensor circuits providing measurement signals representing first and second frequency components of a measured voltage and first and second frequency components of a measured current near the input end of the RF power path. The reactor further includes a processor for providing first and second frequency components of a wafer voltage signal as, respectively, a first sum of the first frequency components of the measured voltage and measured current multiplied by first and second coefficients respectively, and a second sum of the second frequency components of the measured voltage and measured current multiplied by third and fourth coefficients, respectively. A processor produces a D. C. wafer voltage by combining D. C.

US Patent:

7375947, May 20, 2008

Filed:

Feb 7, 2007

Appl. No.:

11/672362

Inventors:

Jang Gyoo Yang - Sunnyvale CA, US
Daniel J. Hoffman - Saratoga CA, US
Steven C. Shannon - San Mateo CA, US
Douglas H. Burns - Saratoga CA, US
Wonseok Lee - Pleasanton CA, US
Kwang-Soo Kim - Santa Clara CA, US

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

H01L 21/283
B23B 31/28

US Classification:

361234, 361233, 279128, 216 67, 216 69

Abstract:

In a plasma reactor having an electrostatic chuck, wafer voltage is determined from RF measurements at the bias input using previously determined constants based upon transmission line properties of the bias input, and this wafer voltage is used to accurately control the DC wafer clamping voltage.

US Patent:

7440859, Oct 21, 2008

Filed:

Dec 29, 2006

Appl. No.:

11/617802

Inventors:

Steven C. Shannon - San Mateo CA, US
Daniel J. Hoffman - Saratoga CA, US
Jeremiah T. P. Pender - San Jose CA, US
Tarreg Mawari - Manassas VA, US

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

G01R 23/16

US Classification:

702 76, 702118, 118712, 15634524, 15634528, 216 59, 216 61, 700108, 700121, 438 9

Abstract:

Methods for determining characteristics of a plasma are provided. In one embodiment, a method for determining characteristics of a plasma includes obtaining metrics of a plasma at two different frequencies, and determining at least one characteristic of the plasma utilizing the metrics. In another embodiment, a method for determining characteristics of a plasma includes obtaining metrics of current and voltage information for first and second waveforms coupled to a plasma at different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform. In another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, and determining at least one characteristic of a plasma using model.

US Patent:

7510665, Mar 31, 2009

Filed:

May 2, 2006

Appl. No.:

11/416468

Inventors:

Steven C. Shannon - San Mateo CA, US
Alexander Paterson - San Jose CA, US
Theodoros Panagopoulos - San Jose CA, US
John P. Holland - San Jose CA, US
Dennis S. Grimard - Ann Arbor MI, US
Daniel J. Hoffman - Saratoga CA, US

Assignee:

Applied Materials, Inc. - Santa Clara CA

International Classification:

G01R 31/00

US Classification:

216 59, 216 61, 216 67, 438706, 438710, 438714

Abstract:

A method for controlling a plasma in a semiconductor substrate processing chamber is provided. The method includes the steps of supplying a first RF signal to a first electrode within the processing chamber at a first frequency selected to cause plasma sheath oscillation at the first frequency; and supplying a second RF signal from the source to the first electrode at a second frequency selected to cause plasma sheath oscillation at the second frequency, wherein the second frequency is different from the first frequency by a differential equal to a desired frequency selected to cause plasma sheath oscillation at the desired frequency.