Metallic Buffer Layer for L10 Perpendicular Media
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Solution Overview
Problem
Conventional hard disk drive systems face challenges in achieving sufficient atomic ordering of FePt thin films at room temperature, leading to damage from high fabrication temperatures required for proper L10 structure formation, which affects storage density and media integrity.
Innovation Solution
A process involving the formation of a metallic buffer layer with a (002) crystalline texture at low temperatures, followed by depositing a perpendicular magnetic recording layer with a L10 structure at elevated temperatures, where metal from the buffer layer 'floats' to enhance atomic ordering and crystalline texture, and is subsequently removed to preserve the granular structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If FePt thin film is deposited at room temperature, then fabrication temperature is low and substrate damage is avoided, but atomic ordering of L10 structure is insufficient
Solution Approach 1:
A metallic buffer layer is deposited beforehand on the substrate before the FePt recording layer. This buffer layer is subsequently removed after serving its purpose of enabling low-temperature deposition with sufficient atomic ordering. The preliminary action of the buffer layer allows the main FePt layer to be deposited at room temperature while achieving the required L10 structure ordering.
Solution Approach 2:
The metallic buffer layer acts as an intermediary between the substrate and the FePt recording layer. It mediates the deposition process by providing a template that enables atomic ordering of the L10 structure at low temperatures. The buffer layer is then removed, leaving the FePt layer with the desired crystalline structure without having been exposed to high temperatures.
2Manufacturing precision
If FePt thin film is deposited at elevated temperature (550°C or above), then atomic ordering of L10 structure is sufficient, but substrate damage occurs
Solution Approach 1:
The metallic buffer layer is deposited in advance to create a foundation that enables low-temperature FePt deposition with adequate atomic ordering. This preliminary structure allows the FePt layer to form with the required L10 structure at room temperature, eliminating the need for high-temperature processing that would damage the substrate.
Solution Approach 2:
The buffer layer serves as a protective intermediary during the deposition process. It allows the FePt layer to achieve sufficient atomic ordering without direct exposure to high temperatures that would damage the substrate. The buffer layer is subsequently removed, having fulfilled its mediating role.
3Object-affected harmful factors
If metallic buffer layer is used to enable low temperature deposition, then substrate damage is avoided, but additional process steps are required
Solution Approach 1:
The metallic buffer layer is deposited to enable low-temperature FePt deposition with sufficient atomic ordering, then it is removed after serving its purpose. This temporary component is discarded after fulfilling its function of protecting the substrate and enabling proper crystalline structure formation, simplifying the overall process by avoiding substrate damage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method enables the formation of a high-density perpendicular magnetic recording medium with enhanced atomic ordering and crystalline texture, improving storage density while avoiding damage to the recording media from high temperatures.
Implementation Method 1
The metallic buffer layer, which comprises a metal such as silver (Ag) or gold (Au), is formed using a deposition process performed at a temperature less than 100° C.
Implementation Method 2
The magnetic recording layer is deposited using a deposition process, such as sputtering, performed at an elevated temperature (i.e., above ambient temperature), such as 350° C. or greater
Implementation Method 3
metal from the metallic buffer layer 'floats' to the top of the magnetic recording layer (i.e., metallic atoms of the magnetic buffer layer transport up through the growing FePt or other L10 material aiding in the atomic ordering process)
Data Source
AI summary
A process of fabricating a perpendicular magnetic recording medium. In one embodiment, the process may comprise forming a metallic buffer layer with a (002) texture on an underlayer using a deposition process performed at a temperature below 30° C. The underlayer may have a crystalline (001) texture. The process may further comprise forming a perpendicular magnetic recording layer on top of the metallic buffer layer using a deposition process performed at a temperature above 350° C. The magnetic recording layer may comprise a magnetic material with a L10 crystalline structure and with a c-axis perpendicular to a plane of the perpendicular magnetic recording layer. The process may further comprise removing metal of the metallic buffer layer from a top surface of the perpendicular magnetic recording layer that moved to the top surface of the perpendicular magnetic recording layer during the forming of the perpendicular magnetic recording layer.