Masanori Sakai

US Patent:

7275304, Oct 2, 2007

Filed:

Mar 4, 2005

Appl. No.:

11/074244

Inventors:

Masanori Sakai - Cupertino CA, US
Kunliang Zhang - Milpitas CA, US
Kenichi Takano - Cupertino CA, US
Yunfei Li - Fremont CA, US
Po-Kang Wang - San Jose CA, US

Assignee:

Headway Technologies, Inc. - Milpitas CA

International Classification:

G11B 5/127
G11B 5/33

US Classification:

2960308, 2960301, 2960313, 2960314, 2960316, 32432412

Abstract:

A hard bias (HB) structure for biasing a free layer in a MR sensor within a magnetic read head is comprised of a main biasing layer with a large negative magnetostriction (λ) value. Compressive stress in the device after lapping induces a strong in-plane anisotropy that effectively provides a longitudinal bias to stabilize the sensor. The main biasing layer is formed between two FM layers, and at least one AFM layer is disposed above the upper FM layer or below the lower FM layer. Additionally, there may be a Ta/Ni or Ta/NiFe seed layer as the bottom layer in the HB structure. Compared with a conventional abutted junction exchange bias design, the HB structure described herein results in higher output amplitude under similar asymmetry sigma and significantly decreases sidelobe occurrence. Furthermore, smaller MRWu with a similar track width is achieved since the main biasing layer acts as a side shield.

US Patent:

7283337, Oct 16, 2007

Filed:

Mar 4, 2005

Appl. No.:

11/074270

Inventors:

Masanori Sakai - Cupertino CA, US
Kunliang Zhang - Milpitas CA, US
Kenichi Takano - Cupertino CA, US
Yunfei Li - Fremont CA, US
Po-Kang Wang - San Jose CA, US

Assignee:

Headway Technologies, Inc. - Mipitas CA

International Classification:

G11B 5/127

US Classification:

36032412

Abstract:

A hard bias (HB) structure for biasing a free layer in a MR sensor within a magnetic read head is comprised of a main biasing layer with a large negative magnetostriction (λ) value. Compressive stress in the device after lapping induces a strong in-plane anisotropy that effectively provides a longitudinal bias to stabilize the sensor. The main biasing layer is formed between two FM layers, and at least one AFM layer is disposed above the upper FM layer or below the lower FM layer. Additionally, there may be a Ta/Ni or Ta/NiFe seed layer as the bottom layer in the HB structure. Compared with a conventional abutted junction exchange bias design, the HB structure described herein results in higher output amplitude under similar asymmetry sigma and significantly decreases sidelobe occurrence. Furthermore, smaller MRWu with a similar track width is achieved since the main biasing layer acts as a side shield.