Apparatus and method for intra process on wafer monitoring of deposited layer permeability

An apparatus for determining a magnetic property of magnetic structures on a wafer, comprising:

• a wafer;
• a plurality of substantially identical magnetic heads fabricated on the wafer;
• a first one of the magnetic heads having at least one coil layer embedded in an insulation stack and the insulation stack being sandwiched between first and second pole pieces;
• a monitoring system for monitoring a magnetic property of a selected portion of the second pole piece of said first magnetic head including:
• first and second replicated magnetic heads wherein each replicated magnetic head replicates said first magnetic head and wherein the first and second replicated magnetic heads have first and second replicated coil layers respectively and first and second replicated second pole pieces respectively;
• means for inductively coupling the first and second replicated magnetic heads;
• a magnetic shaping layer covering each of the first and second replicated second pole pieces except for an exposed portion which corresponds to a selected portion of said second pole piece of said first magnetic head;
• and
• the first replicated coil layer having first and second ends for conducting a current through the first replicated coil;
• and
• the second replicated coil layer having first and second ends for providing an output representing said magnetic property of said selected portion of the second pole piece of said first magnetic heads.

A combination of a monitored magnetic layer and a monitoring system for monitoring a magnetic property of at least one selected portion of said monitored magnetic layer, comprising:

• a wafer;
• a monitored magnetic layer deposited on said wafer by a deposition A;
• at least one monitoring system on said wafer, including:
• first and second monitoring coils deposited on the wafer by a deposition B;
• a monitoring magnetic layer deposited over the first and second monitoring coils respectively by said deposition A, the monitoring magnetic layer substantially replicating said monitored magnetic layer over each of the first and second monitoring coil layers, the monitoring magnetic layer bridging between the first and second monitoring coils to provide inductive coupling therebetween;
• a magnetic shaping layer deposited on top of the monitoring magnetic layer by a deposition C, the magnetic shaping layer covering the monitoring magnetic layer except for an exposed portion of the monitoring magnetic layer which corresponds to said selected portion of the monitored magnetic layer;
• and
• each of the first and second monitoring coils having first and second ends, the first and second ends of the first monitoring coil being connected to first and second pads respectively and the first and second ends of the second monitoring coil being connected to third and fourth pads respectively,
• whereby, in response to an alternating current conducted through the first monitoring coil via said first and second pads, an output due to said inductive coupling between the first and second monitoring coils is generated at the third and fourth pads for indicating said magnetic property of said selected portion of the monitored magnetic layer.

A method for determining a magnetic property of at least one magnetic head at a wafer level, the method comprising:

• depositing at least first, second and third substantially identical magnetic heads on a wafer with each magnetic head having a coil layer and a second pole piece;
• joining the second pole pieces of the second and third magnetic heads so that the coil layers of the second and third magnetic head are magnetically coupled;
• depositing a magnetic shaping layer on top of the second pole pieces of the second and third magnetic heads except for an exposed portion of the second pole piece of one of the second and third magnetic heads, the exposed portion corresponding to a selected portion of the second pole piece of the first magnetic head;
• and
• conducting a current through the coil layer of the second magnetic head and receiving an output from the coil layer of the second magnetic head for indicating said magnetic property of the selected portion of the second pole piece of the first magnetic head.

A method of monitoring a magnetic property of a selected portion of a monitored magnetic layer, the method comprising the steps of:

• providing a wafer;
• depositing said monitored magnetic layer on the wafer by a deposition A;
• fabricating at least one monitoring system on the wafer by:
• depositing first and second monitoring coils on the wafer by a deposition B, with the first monitoring coil having first and second ends, and the second monitoring coil having first and second ends;
• depositing a monitoring magnetic layer over the first and second monitoring coils respectively by said deposition A, the monitoring magnetic layer substantially replicating said monitored magnetic layer, the monitoring magnetic layer bridging between the first and second monitoring coils to provide inductive coupling therebetween;
• depositing a magnetic shaping layer by a deposition C on top of the monitoring magnetic layer that covers the monitoring magnetic layer except for an exposed portion of the monitoring magnetic layer which corresponds to said selected portion of the monitored magnetic layer;
• and
• connecting first and second pads to the first and second ends of the first monitoring coil and connecting third and fourth pads to the first and second ends of the second monitoring coil;
• and
• conducting a current through the first monitoring coil via the first and second pads, and receiving an output at the third and fourth pads indicative of said magnetic property of said selected portion of the monitored magnetic layer.