Manufacturing of hard masks for patterning magnetic media
View Patent ↗Embodiments of the present invention relate to systems and methods for designing and manufacturing hard masks used in the creation of patterned magnetic media and, more particularly, patterned magnetic recording media used in hard disk drives (e.g., bit patterned media (BPM)). In some embodiments, the hard mask incorporates at least one layer of Ta (tantalum) and at least one layer of C (carbon) and is used during ion implantation of a pattern onto magnetic media. The hard mask can be fabricated with a high aspect ratio to achieve small feature sizes while maintaining its effectiveness as a mask, is robust enough to withstand the ion implantation process, and can be removed after the ion implantation process with minimal damage to the magnetic media.
1. A method for manufacturing a magnetic recording medium, the method comprising:
depositing a carbon (C) layer over a magnetic layer of the magnetic recording medium;
depositing a tantalum (Ta) layer over the carbon layer;
depositing a photoresist layer over the tantalum layer;
patterning the photoresist layer to form a photoresist patterned layer;
transferring the photoresist patterned layer to the tantalum layer to form a tantalum patterned layer; and
transferring the tantalum patterned layer to the carbon layer to form a patterned carbon layer, wherein a residual layer of the photoresist patterned layer remains after transferring the tantalum patterned layer to the carbon layer, wherein the residual layer allows portions of the tantalum mask layer to be removed before the residual layer is completely etched away,
wherein the carbon layer is etched such that etched features of the carbon patterned layer have residual carbon layer remaining after etching through which implantation is performed, wherein no portion of the magnetic layer is exposed.
2. The method of claim 1 , further comprising performing the implantation process.
3. The method of claim 1 , further comprising removing the tantalum layer and removing the carbon layer.
4. The method of claim 3 , wherein removing the tantalum layer comprises plasma etching using a fluorine-based gas chemistry.
5. The method of claim 3 , wherein removing the carbon layer comprises dry etching using a hydrogen-based gas chemistry.
6. The method of claim 1 , wherein transferring the tantalum patterned layer to the carbon layer comprises dry etching using an oxygen-based gas chemistry.
7. The method of claim 1 , wherein transferring the photoresist patterned layer to the tantalum layer comprises dry etching using a fluorine-based gas chemistry.
8. The method of claim 1 , wherein the tantalum layer has a thickness sufficient to still cover the carbon layer subsequent to the photoresist patterned layer being etched into the tantalum layer.
9. The method of claim 1 , wherein the tantalum layer has a thickness sufficient to protect the carbon layer subsequent to the photoresist patterned layer being etched into the tantalum layer.
10. The method of claim 1 , wherein the tantalum layer has a thickness between approximately 1 nm and 2 nm.