David W Bullock

US Patent:

59683740, Oct 19, 1999

Filed:

Mar 20, 1997

Appl. No.:

8/822588

Inventors:

David M. Bullock - Highland Village TX

Assignee:

Lam Research Corporation - Fremont CA

International Classification:

H01B 1300
B44C 122

US Classification:

216 16

Abstract:

A method in a variable-gap plasma processing chamber for controlled removal of at least a portion of an upper crust of a photoresist layer disposed above a substrate. The upper crust represents a hardened upper layer of the photoresist layer. The method includes loading the substrate into the variable-gap plasma processing chamber. The method further includes flowing an ash source gas comprising O. sub. 2 into the variable-gap plasma processing chamber. The ash source gas is substantially free of an O. sub. 2 bombarding gas. The method further includes performing the controlled removal of at least the portion of the upper crust of the photoresist layer with a plasma struck from the ash source gas while a gap between an upper surface of the substrate and an upper electrode of the variable-gap plasma processing chamber is maintained at a predefined wide gap distance. Preferably, the predefined wide gap distance represents a distance sufficiently wide for the substrate to be loaded into the variable-gap plasma chamber without having to alter the gap.

US Patent:

41931246, Mar 11, 1980

Filed:

Mar 20, 1978

Appl. No.:

5/888124

Inventors:

David C. Bullock - Dallas TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G11C 1908

US Classification:

365 12

Abstract:

Input swap transfer/replicate gate and output replicate gate for use in a magnetic bubble memory arrangement between the bubble storage loops and the input and output sections respectively on opposite sides thereof. The input swap transfer/replicate gate and the output replicate gate are of double level construction, each type of gate including a hairpin element at the first level and mounted on a planar layer of bubble-supporting magnetic material on which bubble propagation elements of magnetically soft material are disposed. The bubble propagation elements are arranged to form propagation paths defining a bubble input section, a bubble output section, and a plurality of closed storage loops defining a bubble storage section interposed between the input and output bubble sections. The second levels of the swap transfer/replicate gate and output replicate gate are situated at the input and output ends of the storage loops, forming the opposite bights of the loop. Each type of gate at the second level comprises an asymmetric hook-like transfer/replicate element whose opposite ends are respectively disposed in the opposite courses of the storage loop of which it forms a bight.

US Patent:

41569350, May 29, 1979

Filed:

May 10, 1977

Appl. No.:

5/795475

Inventors:

David C. Bullock - Dallas TX
Robert E. Fontana - Dallas TX
James T. Carlo - Richardson TX
Shalendra K. Singh - Dallas TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G11C 1908

US Classification:

365 15

Abstract:

Magnetic bubble domain memory circuit in which magnetizable overlay patterns of magnetically soft material, e. g. permalloy, are provided as bubble propagation elements on a bubble-supporting magnetic layer to define major and minor bubble propagation paths. The major bubble propagation paths provide interchangeable bubble input and output sections, and the minor bubble propagation paths are in the form of closed storage loops providing a bubble storage section comprising first and second pairs of blocks. Bubble generators are provided for each of the blocks included in the first and second pairs thereof comprising the bubble storage section, along with first and second detectors and input/output tracks of bubble propagation elements associated with the respective pairs of blocks of storage loops. Swap transfer/replicate gates are disposed between the input/output tracks and each of the storage loops included in the blocks of storage loops. These gates are alternately operable in a swap transfer mode and a replicate mode so as to simultaneously transfer data as represented by magnetic bubbles and voids from the tracks to the storage loops and from the storage loops to the tracks when operated in a swap transfer mode, and to split respective magnetic bubbles incident thereon in a replicate mode to form a duplicate magnetic bubble in addition to the original magnetic bubble so as to preserve the data intact in the minor storage loop while delivering a bubble to a detector for readout.

US Patent:

42996805, Nov 10, 1981

Filed:

Dec 31, 1979

Appl. No.:

6/108888

Inventors:

Robert E. Fontana - Dallas TX
David C. Bullock - Dallas TX
Shalendra K. Singh - Dallas TX
John M. Bush - Plano TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

C23C 1500
C23F 102

US Classification:

204192E

Abstract:

Method of fabricating a magnetic bubble memory device in which the magnetizable upper overlay pattern of magnetically soft material, e. g. permalloy, defining bubble propagation elements and bubble function-determining components as located above a bubble-supporting magnetic film is disposed in a wholly planar configuration to avoid bubble propagation anomalies encountered with typical non-planar overlay patterns of magnetically soft material. The fabrication method provides for the consecutive deposition onto a substrate having a magnetic film capable of supporting magnetic bubbles of a layer of non-magnetic electrically conductive material, a layer of insulating material, and a layer of magnetically soft material, such as permalloy. Patterning of the layers then proceeds from the uppermost layer downwardly in stages to form magnetically soft components defining the elements of magnetic bubble propagation paths and magnetic bubble function-determining components as a planar upper overlay pattern from the layer of magnetically soft material, insulation spacers from the layer of insulating material, and control conductors as a planar lower overlay pattern from the layer of non-magnetic electrically conductive material. Patterning of the respective layers is preferably achieved by ion milling of selected portions of the layer of magnetically soft material as defined by a first mask and by sequential plasma etching of selected portions of the underlying layer of insulating material and the layer of non-magnetic electrically conductive material as defined by a second composite mask partially comprising the overlay pattern of magnetically soft material and photoresist material.

US Patent:

39965767, Dec 7, 1976

Filed:

Mar 17, 1975

Appl. No.:

5/559627

Inventors:

David Carl Bullock - Richardson TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G11C 1114
G11C 1142

US Classification:

340174TF

Abstract:

A magnetic bubble detector utilizing a thin film optical waveguide. Light is optically coupled into the guide for propagation of linearly polarized light along a first axis thereof. Magnetic bubbles from a memory storage location are moved past the sensor on a second axis transverse the first. A sensor is provided for sensing changes in the polarization mode of the light propagating along the axis of the waveguide. The sensor includes an optical device for coupling light out of the waveguide. The passage of a magnetic bubble along the second axis past the waveguide will modulate the polarized light by the fringing field of the bubble and provide a light output signal from the sensor indicating the passage of each bubble.

US Patent:

40865711, Apr 25, 1978

Filed:

Feb 24, 1977

Appl. No.:

5/771702

Inventors:

David Carl Bullock - Richardson TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G11C 1908

US Classification:

365 36

Abstract:

Magnetic bubble domain generator and annihilator for use in a magnetic bubble domain memory device of the major-minor bubble propagation path type. The magnetic bubble domain generator and annihilator structure employs a thin metallic loop which is disposed adjacent to a bubble propagation path and is alternatively operable in both a bubble generation and bubble annihilation mode. A DC bias field is provided to the magnetic bubble domain memory circuit device and exists within the metallic loop of the bubble generator and annihilator structure. Upon applying a current pulse to the thin metallic loop from a pulse generator, the bubble generator and annihilator structure is caused to operate in one of the two possible modes. When the current pulse reduces the DC bias field below a predetermined value, the metallic loop operates as a generator to generate a magnetic bubble. Conversely, when the current pulse raises the DC bias field within the metallic loop above a predetermined value, a magnetic bubble within the loop is annihilated.

US Patent:

40865720, Apr 25, 1978

Filed:

Feb 23, 1977

Appl. No.:

5/771293

Inventors:

David Carl Bullock - Richardson TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G11C 1908

US Classification:

365 12

Abstract:

Magnetic bubble domain replicator structure as employed in a magnetic bubble domain memory circuit device of the major-minor bubble propagation path type. The magnetic bubble domain replicate structure comprises a thin metallic conducting loop whose opposite sides are in contact with consecutive elements of magnetically soft material (e. g. , permalloy) defining a propagation path aligned transversely with respect to a minor bubble propagation path employed for data storage. A DC bias field is provided for the magnetic bubble domain memory circuit and exists within the thin metallic loop of the replicate structure. The occurrence of a current pulse from a pulse generator directed to the thin metallic loop so as to reduce the DC bias field therein below a predetermined value at the same time that a magnetic bubble is within the metallic loop causes replication splitting the magnetic bubble into a pair of bubbles.

US Patent:

40400190, Aug 2, 1977

Filed:

Aug 23, 1974

Appl. No.:

5/499823

Inventors:

David Carl Bullock - Richardson TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G11C 1114

US Classification:

340174TF

Abstract:

A magnetic bubble domain memory device employing a major row of contiguous regions for major loop bubble travel and a plurality of minor rows of contiguous regions for minor loop bubble travel, wherein the remainder of the magnetic domain-supporting layer in which the respective major and minor rows are provided includes ion-implanted regions. The edges of the ion-implanted regions adjacent the major and minor rows form rails to which magnetic bubble domains adhere and along which they may be propagated. The end region of each minor row is preferably positioned abreast a cusp between regions in the major row to effect zero degree phase transfer. Thin metallic loops are used for bubble generation and annihilation and, with respect to a Permalloy expansion detector, for replication. Metal masking improves the reliability of the boundaries between the non-implanted regions and the ion-implanted regions, especially with respect to the definition of the cusps between adjacent non-implanted regions in a row.