Patent ID: 6099699
Filing Date: 2000-08-08
Classification: C23C,G11B

Abstract:
An overcoat deposition process for encapsulating a thin film magnetic head with a protective layer of an encapsulation material using a continuous sputtering process comprising the steps of:providing a substrate having a stack of head components that are ready to receive the protective layer;providing a sputtering system for depositing the protective layer from a target that contains the encapsulation material;the sputtering system including a chamber in which the sputtering process is conducted, the substrate being within the chamber and the target being within the chamber;biasing the target to a target bias voltage value relative to the chamber;biasing the substrate to a first substrate bias voltage value relative to the chamber, the first substrate bias voltage value being different than the target bias voltage value;beginning to deposit the protective layer onto the head components from the target while maintaining the first substrate bias voltage value substantially constant, and for a first time interval to produce a first depth of the encapsulation material that is sufficient to cover the fabricated stack;gradually increasing bias power that is applied to the target during the first time interval;thereafter gradually increasing the substrate bias voltage value from the first value to a higher value over a second time interval while continuing to deposit a second depth of the encapsulation material onto the first depth of the encapsulation material;thereafter maintaining the higher substrate bias voltage value substantially constant for a third time interval while continuing to deposit a third depth of the encapsulation material onto the second depth of encapsulation material; andstopping the sputtering process when a total depth of the first, second and third depths of encapsulation material equals a desired depth.