Multi-layer gap structure for high resolution magnetoresistive read head

DETAILED DESCRIPTION The present invention provides a method of constructing a narrow gap read head which will not short between lead layers and shield layers and which has a more planar MR region.
This is accomplished by a two step process of depositing first gap layers before the MR sensor is deposited and a two step process of depositing second gap layers after the MR sensor is deposited.
In the invention a very thin first gap layer G1 is deposited on the first shield layer S1.
An MR region is then masked and a first gap pre-fill layer G1P, which may be thicker than G1, is deposited.
The mask is removed, leaving the first gap pre-fill layer G1P everywhere except in the MR region.
Lead layers L1 and L2 and an MR sensor are formed.
Several novel embodiments of this construction are explained in the detailed description.
In one embodiment planarization is enhanced in the MR region so that a high resolution second pole tip of a write head can be constructed.
Next, a very thin second gap layer G2 is deposited.
The MR region is then masked and a second gap pre-fill layer G2P is deposited.
After lifting off the mask, the G2P layer is located everywhere except in the MR region.
The result is that very thin G1 and G2 layers are in the MR region at the bottom and top of the MR sensor to provide the MR head with a high linear resolution, the G1 and G1P layers are located between the leads and the first shield layer S1 to prevent shorting between the lead layers and the first shield layer S1, and the G2 and G2P layers are located between the lead layers and the second shield layer S2 to prevent shorting between the lead layers and the second shield layer S2.
An object of the present invention is to provide a read head which has a very narrow gap and yet will not short between lead layers and the first and second shield layers.
Another object is to provide a method of constructing a first gap layer of an MR read head with a thickness which is not dependent upon a reduction in thickness of the first gap layer, under the MR sensor, even when the MR sensor is defined by ion beam milling