International Business Machines Corporation

Hitachi Global Storage Technologies Netherlands B.v.

Gtat Corporation

Thomas Edward Dinan, Jr

Neil Leslie Robertson

Richard Hsiao

Son Van Nguyen

Jeffrey Scott Lille

Emanuel Israel Cooper

Ashok Lahiri

Hugo Alberto Emilio Santini

Venkatesan Murali

Gopal Prabhu

Clinton David Snyder

John I Kim

Mike Ming Yu Chen

Alan Jun-Yuan Tam

Lubomyr Taras Romankiw

Murali Ramasubramanian

Paul Phong Nguyen

Madhav Datta

Thomas Safron Kanarsky

Scott Arthur MacDonald

Hong Xu

Eric James Lee

Thao Pham

Michael B Pike

April Dawn Hixson-Goldsmith

Orion Leland

Steve Bababyan

Ravindra Vaman Shenoy

Alan Jun-Yuen Tam

The invention provides a method of forming an electronic device from a lamina that has a coefficient of thermal expansion that is matched or nearly matched to a constructed metal support. In some embodiments the method comprises implanting the top surface of a donor body with an ion dosage to form a cleave plane followed by exfoliating a lamina from the donor body. After exfoliating the lamina, a flexible metal support that has a coefficient of thermal expansion with a value that is within 10% of the value of the coefficient of thermal expansion of the lamina is constructed on the lamina. In some embodiments the coefficients of thermal expansion of the metal support and the lamina are within 10% or within 5% of each other between the temperatures of 100 and 600&#xb0; C.

Multi-layer metal support

The invention provides for a semiconductor wafer with a metal support element suitable for the formation of a flexible or sag tolerant photovoltaic cell. A method for forming a photovoltaic cell may comprise providing a semiconductor wafer have a thickness greater than 150 &#x3bc;m, the wafer having a first surface and a second surface opposite the first and etching the semiconductor wafer a first time so that the first etching reduces the thickness of the semiconductor wafer to less than 150 &#x3bc;m. After the wafer has been etched a first time, a metal support element may be constructed on or over the first surface; and a photovoltaic cell may be fabricated, wherein the semiconductor wafer comprises the base of the photovoltaic cell.

Method for forming flexible solar cells

The magnetic head includes a P2 pole tip in which the P2 pole tip material is electroplated upon a sidewall of the P2 pole tip photolithographic trench. To accomplish this, a block of material is deposited upon a write gap layer, such that a generally straight, vertical sidewall of the block of material is disposed at the P2 pole tip location. Thereafter, an electroplating seed layer is deposited upon the sidewall. A P2 pole tip trench is photolithographically fabricated such that the sidewall (with its deposited seed layer) is exposed within the P2 pole tip trench. Thereafter, the P2 pole tip is formed by electroplating pole tip material upon the seed layer and outward from the sidewall within the trench, The width of the P2 pole tip is thus determined by the quantity of pole tip material that is deposited upon the sidewall.

Narrow write head pole tip fabricated by sidewall processing

The magnetic head includes a Ppole tip in which the Ppole tip material is electroplated upon a sidewall of the Ppole tip photolithographic trench. To accomplish this, a block of material is deposited upon a write gap layer, such that a generally straight, vertical sidewall of the block of material is disposed at the Ppole tip location. Thereafter, an electroplating seed layer is deposited upon the sidewall. A Ppole tip trench is photolithographically fabricated such that the sidewall (with its deposited seed layer) is exposed within the Ppole tip trench. Thereafter, the Ppole tip is formed by electroplating pole tip material upon the seed layer and outward from the sidewall within the trench. The width of the Ppole tip is thus determined by the quantity of pole tip material that is deposited upon the sidewall.

The present invention includes an overplated component which includes an enlarged mushroom head having outer portions which overhang a hard baked resist layer. The device is ultimately encapsulated such that no voids and/or redeposition problems exist under the overhang due to the presence of the hard baked resist. While not intended to be limiting in any manner, a device of the present invention is a thin film magnetic head wherein the yoke portion of a magnetic pole is formed utilizing the mushroom plating techniques of the present invention. Another mushroom plated component found in many devices is a mushroom plated electrical interconnecting stud that is formed utilizing the process steps of the present invention.

Self-aligned void filling for mushroomed plating

A method and apparatus using a pre-patterned seed layer for providing an aligned coil for an inductive head structure. The method uses an aligned process where the base plate imprint is fabricated on an electrically insulating layer and the reversed image is fabricated and etched into the coil insulation material, e.g., hard bake photoresist to alleviate the problems associated with complete ion removal of the seed layer between high aspect ratio coils. The method would also not be prone to plating non-uniformities (voids), and would not be subject to seed layer undercutting in a wet etch step process.

Method and apparatus using a pre-patterned seed layer for providing an aligned coil for an inductive head structure

A process for electroplating and annealing thin-films of nickel-iron alloys having from 63% to 81% iron content by weight to produce pole pieces having saturation flux density (B) in the range from 1.9 to 2.3 T (19 to 23 kG) with acceptable magnetic anisotropy and magnetostriction and a coercivity (H) no higher than 160 A/m (2 Oe). The desired alloy layer properties, including small crystal size and minimal impurity inclusions, can be produced by including higher relative levels of Feions in the electroplating bath while holding the bath at a lower temperature while plating from a suitable seed layer. The resulting alloy layer adopts a small crystal size (BCC) without significant inclusion of impurities, which advantageously permits annealing to an acceptable Hwhile retaining the high Bdesired.

Method for electroplating a body-centered cubic nickel-iron alloy thin film with a high saturation flux density

A magnetic head for a hard disk drive. The magnetic poles of the head are formed with a NiFe alloy having a graduated composition in which a higher Fe concentration is fabricated proximate the write gap layer between the magnetic poles. Each magnetic pole is fabricated in a single electroplating step in which the duty cycle of the electroplating current is altered during the electroplating operation. Where the duty cycle is greatest the Fe ion concentration is likewise greatest.

Magnetic head for hard disk drive having varied composition nickel-iron alloy magnetic poles

A thin-film write head employing pole pieces formed of an electroplated body-centered cubic (BCC) nickel-iron alloy with a saturation flux density (B) of 1.9 to 2.3 T (19 to 23 kG) and an acceptable coercivity (H) of about 80 to about 160 A/m (1-2 Oe). The iron content of the electroplated nickel-iron alloy is from 64% to 81% by weight. The two-layer pole fabrication process holds magnetic anisotropy and coercivity to useable values while improving saturation flux density and optimizing magnetostriction. This is accomplished by first electroplating a BCC nickel-iron layer onto an underlying seed layer and then annealing the two layers to reduce coercivity to less than about 160 amps/meter and raise magnetization to acceptable levels.

High-saturation thin-film write head for high-coercivity magnetic data storage media

A cobalt-iron alloy film having saturation magnetization of at least about 2.30 Telsa. The film alloy includes about 55 wt % to about 75 wt. % iron and the remainder cobalt. The film is made by a process in which the film is electrodeposited from an aqueous medium which includes one or more ferrous salts, one or more cobaltous salts, a buffer having a pKa of about 6 to about 8, at least one carboxylic acid having a pKa of between about 3.5 and about 5.5, an aromatic sulfinic acid or its salt and optionally, a halide salt and/or a surfactant. The alloy film is useful as a write head in magnetic recording.

CoFe alloy film and process of making same

A method of making a magnetic read/write head using a single lithographic step to define both a write coil and a pole tip structure. The use of a thin image resist layer over a hard reactive-ion etch mask and image transfer techniques allows very high resolution optical lithography which can accommodate formation of a very compact coil and pole structure. The use of a single high resolution lithography step on a planarized structure to define both a write pole tip and a write coil coplanar with the write pole tip avoids the problems of reflective notching associated with lithography to define the pole tip in the vicinity of non-planar features of the coil structure and also eliminates alignment inaccuracies inherent in separate lithography processes for the coil and pole.

Simultaneous definition and direct transfer of a write head pole and coil for a magnetic read/write head

An etch barrier to be used in a photolithograph process is disclosed. A silicon rich etch barrier is deposited on a substrate using a low energy deposition technique. A diamond like carbon layer is deposited on the silicon rich etch barrier. Photoresist is then placed on this etch barrier DLC combination. To form photolithographic features, successive steps of oxygen and flourine reactive ion etching is used.

Method of manufacturing high aspect ratio photolithographic features

A method of manufacturing includes 2 mushroom plating process starts with an overplated component which includes an enlarged mushroom head having outer portions which overhang a resist layer. The next step in the first process embodiment is a heating step in which the resist layer is hard baked. Thereafter, using a dry etch process, such as a reactive ion etch (RIE) process, the hard baked resist layer is removed in all areas except beneath the overhang of the mushroom head. The area beneath the overhang thereby remains filled with hard baked resist. Thereafter, the device is ultimately encapsulated such that no voids and/or redeposition problems exist under the overhang due to the presence of the hard baked resist. In an alternative process embodiment of the present invention the dry etch process is conducted first upon the resist layer, such that the resist layer is removed in all areas except under the overhang. Thereafter, the device is baked, such that hard baked resist remains beneath the overhang. Ultimately, the device is encapsulated and no voids or redeposition problems exist beneath the overhang due to the presence of the hard baked resist.

In the NiFe electroplating method of the present invention, the atomic percent (at. %) composition of Ni and Fe in NiFe electroplated material is controlled by selection of the duty cycle of the electroplating current during the electroplating process. Generally, for a particular electroplating bath, where the electroplating current duty cycle is greatest the NiFe electroplated material has a higher Fe at. %, and where the electroplating current duty cycle is reduced, a lower Fe at. %. Therefore, electroplated NiFe components from a single electroplating bath can have differing NiFe concentrations where the electroplating current duty cycle is altered. Additionally, NiFe components can be electroplated with a graduated or changing Ni and Fe concentration by altering the electroplating current duty cycle during the electroplating process.

Growing community of inventors

San Jose, CA, United States of America

Thomas Edward Dinan, Jr