Laser heat sinking for integrating laser diode into recording heads at wafer level

Patent metadata

Field	Value
Publication number	US-12451666-B2
Application number	US-202217657164-A
Country	US
Kind code	B2
Filing date	Mar 30, 2022
Priority date	Mar 30, 2022
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

A method comprising the steps of forming a recording head comprising a waveguide, a heat sink and a bleed resistor on a first substrate, is described. The bleed resistor is coupled to the heat sink and the substrate. The top surface of the heat sink is planarized to form a planarized heat sink. A laser diode formed on a second substrate is transfer printed onto the planarized heat sink to form an integrated laser diode.

First claim

What is claimed is:

1. A method comprising the steps of:
forming a recording head comprising a waveguide on a first substrate;
forming a heat sink on the first substrate;
forming a bleed resistor on the first substrate, wherein the bleed resistor is coupled to the heat sink and the substrate;
planarizing a top surface of the heat sink to form a planarized heat sink; and
transfer printing a laser diode formed on a second substrate onto the planarized heat sink to form an integrated laser diode.

2. The method of claim 1 , wherein planarizing the top surface of the heat sink includes planarizing the heat sink such that the integrated laser diode is aligned with the waveguide.

3. The method of claim 2 , wherein aligning the integrated laser diode to the waveguide includes aligning the laser diode within about 50 nm to about 150 nm in a z-direction.

4. The method of claim 1 , wherein planarizing the heat sink results in a surface roughness of the planarized heat sink of less than about 0.5 nm root mean squared.

5. The method of claim 1 , wherein planarizing the top surface of the heat sink comprises at least one of mechanically polishing, chemically polishing or chemically mechanically polishing the top surface of the heat sink.

6. The method of claim 1 , further comprising configuring the bleed resistor to prevent ESD damage to the laser diode during transfer printing.

7. The method of claim 1 , further comprising configuring the bleed resistor to prevent ESD damage to the laser diode after transfer printing.

8. The method of claim 1 , wherein a resistance of the bleed resistor is between about 5 and about 10 kilo-Ohms.

9. The method of claim 1 , wherein depositing the heat sink comprises depositing a multilayer structure.

10. The method of claim 1 , wherein the heat sink comprises Cu, AIN, Au, NiFe, NiCr, Al 2 O 3 , CuW or combinations thereof.

11. The method of claim 1 , further comprising electrically grounding the first substrate.

Assignees

• Seagate Technology Llc

Inventors

• El Hallak Fadi
• Howells Bryn John
• Boyle Michael Gerald
• Mcginnity Frank Anthony
• Mcgarry Martin Liam

Classifications

• G11B2005/0021

  Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal · CPC title

• G11B5/127 Primary

  Structure or manufacture of heads, e.g. inductive · CPC title

• G11B5/40

  Protective measures on heads, e.g. against excessive temperature  (G11B5/31 takes precedence; protection against wear G11B5/255  {; protective structure of the head: see under structures, e.g. G11B5/3106}) · CPC title

• H01S5/026

  Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers (stabilisation of output H01S5/06) · CPC title

• H01S5/06825

  Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation · CPC title