Method for sensor edge control and track width definition for narrow track width devices
View Patent ↗A process for defining and controlling the track width for sensor devices is disclosed. An RIE-resistant, image layer, such as Cu or NiFe, is deposited after the DLC layer. A combination of RIE and ion milling processes or reactive ion beam etching processes are used to form the mask structure. Having an RIE-resistant layer precisely defines the DLC edge and minimizes the line edge roughness that result from fast removal of duramide during RIE. This solution controls the formation of the edges of the sensors and provides good definition for DLC mask edges. The image layer may be chemical mechanical polished to eliminate ion milling before the final RIE step.
1. A method of modifying a track width of a structure with a mask, the method comprising:
(a) providing a sensor having a track width;
(b) forming a mask on the sensor, the mask having a DLC layer, a hydrophilic polymer of acrylamide layer, a photoresist layer, and an image layer of RIE-resistant material located directly between and in contact with the DLC layer and the hydrophilic polymer of acrylamide layer; and then
(c) processing the sensor and the mask to reduce the track width of the sensor to a narrow track width of less than approximately 100 nm.
2. A method according to claim 1 , wherein step (c) comprises processing the sensor and the mask with processes selected from the group consisting of RIE, ion milling, and reactive ion beam etching.
3. A method according to claim 1 , wherein the image layer comprises a material selected from the group consisting of Rh, Cu, and NiFe.
4. A method according to claim 1 , wherein the image layer has a thickness in a range of approximately 20 to 100 Å in a direction perpendicular to the track width of the sensor.
5. A method of reducing a track width of a sensor, the method comprising:
(a) forming a sensor having a track width extending in a horizontal direction;
(b) forming a mask on top of the sensor in a vertical direction that is perpendicular to the horizontal direction, the mask having a DLC layer, a hydrophilic polymer of acrylamide layer, a photoresist layer, and an image layer of RIE-resistant material located directly between and in contact with the DLC layer and the hydrophilic polymer of acrylamide layer, the image layer having a thickness in the vertical direction in a range of approximately 20 to 100 Å;
(c) spin processing the mask;
(d) exposing and developing the mask;
(e) reactive ion etching the mask;
(f) ion milling the image layer;
(g) reactive ion etching the mask; and
(h) reducing the track width of the sensor to a narrow track width of less than approximately 100 nm.
6. A method according to claim 5 , wherein step (e) comprises reactive ion etching the hydrophilic polymer of acrylamide layer, step (g) comprises reactive ion etching the DLC layer, and step (h) comprises ion milling the sensor.
7. A method according to claim 5 , further comprising precisely defining an edge of the DLC layer with the image layer to reduce a line edge roughness of the DLC layer.
8. A method according to claim 5 , further comprising chemical mechanical polishing the image layer to eliminate ion milling before step (g).
9. A method according to claim 5 , further comprising processing the mask with processes selected from the group consisting of RIE, ion milling, and reactive ion beam etching to form the mask.
10. A method according to claim 5 , further comprising forming the image layer with a material selected from the group consisting of Rh, Cu, and NiFe.
11. A method according to claim 5 , further comprising removing the image layer with physical sputtering.
12. A method of reducing a track width of a sensor, comprising:
(a) forming a sensor having a track width extending in a horizontal direction;
(b) forming a mask on top of the sensor in a vertical direction that is perpendicular to the horizontal direction, the mask having a DLC layer, a hydrophilic polymer of acrylamide layer, a photoresist layer, and an image layer of RIE-resistant material selected from the group consisting of Rh, Cu, and NiFe, located directly between and in contact with the DLC layer and the hydrophilic polymer of acrylamide layer, the image layer having a thickness in the vertical direction in a range of approximately 20 to 100 Å;
(c) spin processing the mask;
(d) exposing and developing the mask;
(e) reactive ion etching the hydrophilic polymer of acrylamide layer;
(f) ion milling the image layer;
(g) reactive ion etching the DLC layer; and
(h) ion milling the sensor and reducing the track width of the sensor to a narrow track width of less than approximately 100 nm.
13. A method according to claim 12 , further comprising precisely defining an edge of the DLC layer with the image layer to reduce a line edge roughness of the DLC layer.
14. A method according to claim 12 , further comprising chemical mechanical polishing the image layer to eliminate ion milling before step (g).
15. A method according to claim 12 , further comprising processing the mask with processes selected from the group consisting of RIE, ion milling, and reactive ion beam etching to form the mask.
16. A method according to claim 12 , further comprising removing the image layer with physical spuffering.