HAMR Overcoat Oxide Segmentation for NFT Corrosion Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heat assisted magnetic recording (HAMR) processes face challenges due to harsh environments with high temperatures, humidity, and oxidation, which can be corrosive and damage delicate structures like near field transducers (NFTs) and write poles, necessitating robust overcoats.
Innovation Solution
The use of overcoats comprising oxides of yttrium, scandium, lanthanoids, actinoids, and zinc, with an inner layer in contact with the NFT and an outer layer of aluminum oxide, silicon oxide, tantalum oxide, or hafnium oxide, providing enhanced adhesion and gas barrier properties to protect the NFT and magnetic writer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional overcoats are used in HAMR processes, then the structure is simple and easy to manufacture, but the overcoat fails to protect against corrosion in high temperature, high humidity, and oxidative environments
Solution Approach 1:
The overcoat is divided into multiple distinct layers: an inner layer comprising oxides of yttrium, scandium, lanthanoids, actinoids, or zinc and an outer layer comprising aluminum oxide, silicon oxide, tantalum oxide, or hafnium oxide. This segmentation allows each layer to perform specific functions - the inner layer provides adhesion to the NFT while the outer layer provides corrosion resistance and gas barrier properties, thereby resolving the contradiction between reliability and complexity.
Solution Approach 2:
The patent employs composite material structure by combining different oxide materials in layered configuration. The inner layer uses oxides such as yttrium oxide, scandium oxide, or zinc oxide that provide strong adhesion to the NFT, while the outer layer uses oxides like aluminum oxide, silicon oxide, tantalum oxide, or hafnium oxide that provide superior corrosion resistance and gas barrier properties. This composite approach enables the overcoat to simultaneously achieve both adhesion and corrosion protection, resolving the technical contradiction.
2Reliability
If the overcoat is made thicker to improve corrosion protection, then reliability improves, but manufacturing precision and device complexity increase
Solution Approach 1:
Instead of using a single thick overcoat layer that would be difficult to manufacture with precise thickness control, the patent segments the overcoat into multiple thinner layers. The inner layer and outer layer can each be deposited with controlled thicknesses, and together they provide the necessary corrosion protection. This segmentation reduces the manufacturing precision challenge while maintaining or improving overall reliability.
3Reliability
If standard overcoats are used, then manufacturing is simple, but gas permeability is high leading to NFT recession
Solution Approach 1:
The patent uses composite oxide materials in a layered structure where the outer layer comprises oxides such as aluminum oxide, silicon oxide, tantalum oxide, or hafnium oxide that provide excellent gas barrier properties with low permeability. This composite material approach reduces gas permeability to protect the NFT from recession while maintaining ease of manufacture through established oxide deposition techniques, thereby resolving the contradiction between reliability and ease of manufacture.
Data Source
AI summary
A magnetic device including a magnetic writer; and an overcoat positioned over at least the magnetic writer, the overcoat including oxides of yttrium, oxides of scandium, oxides of lanthanoids, oxides of actionoids, oxides of zinc, or combinations thereof.