Planar PMR disks consist of a stack of thin layers deposited sequentially across the entire disk surface in a vacuum system. Each layer performs a specific function to ensure vertical media orientation and magnetization perpendicular to the plane of the film. PMR technology advances have been achieved by continuously reducing head/media space dimensions including head geometry, media grain size, head-media spacing and other dimensions.
PMR versus Longitudinal Magnetic Recording (LMR)
- Grain structure and the magnetic orientation of the stored data of PMR media is columnar instead of longitudinal.
- PMR provides improved thermal stability, signal-to-noise ratio (SNR), and writability.
- High SNR is necessary to read back written information reliably.
The graph to the left demonstrates the layering structure of today’s second-generation PMR, next-generation PMR, and future media designs. The need for heating and sputter-etching with 10 layers will require additional process chambers to increase deposition capabilities to at least 13 individual layers. The 200 Lean® can accommodate up to 28 process chambers without significantly impacting the footprint.