Manufacturable gallium and nitrogen containing single frequency laser diode
A method for manufacturing an optical device includes providing a carrier waver, provide a first substrate having a first surface region, and forming a first gallium and nitrogen containing epitaxial material overlying the first surface region. The first epitaxial material includes a first release material overlying the first substrate. The method also includes patterning the first epitaxial material to form a plurality of first dice arranged in an array; forming a first interface region overlying the first epitaxial material; bonding the first interface region of at least a fraction of the plurality of first dice to the carrier wafer to form bonded structures; releasing the bonded structures to transfer a first plurality of dice to the carrier wafer, the first plurality of dice transferred to the carrier wafer forming mesa regions on the carrier wafer; and forming an optical waveguide in each of the mesa regions, the optical waveguide configured as a cavity to form a laser diode of the electromagnetic radiation.
1 . A method for manufacturing an optical device, the method
providing a carrier wafer;
providing a first substrate having a first surface region;
forming a first gallium and nitrogen containing epitaxial material overlying the first surface region, the first epitaxial material comprising a first release material overlying the first substrate and one or more n-type gallium and nitrogen containing layers, one or more light emitting gallium and nitrogen containing layers comprising an active region configured to emit electromagnetic radiation at a first wavelength, and one or more p-type gallium and nitrogen containing layers overlying the first release material;
patterning the first epitaxial material and forming mesas to form a plurality of first dice arranged in an array;
forming a first interface region overlying the first epitaxial material;
bonding the first interface region of at least a fraction of the plurality of first dice to the carrier wafer to form bonded structures;
releasing the bonded structures to transfer a first plurality of dice to the carrier wafer, the first plurality of dice transferred to the carrier wafer forming mesa regions on the carrier wafer;
forming grating features in the one or more n-type gallium and nitrogen containing layers of each of the mesa regions; and
forming an optical waveguide in each of the mesa regions, the optical waveguide configured as a cavity to form a laser diode of the electromagnetic radiation; wherein the grating features in the one or more n-type gallium and nitrogen containing layers are configured to provide feedback to the electromagnetic radiation.
2 . The method of claim 1 , wherein the cavity is configured as a laser diode operating in a 390 nm to 550 nm wavelength range, and wherein at least one of:
the grating features are configured to provide optical feedback to form a distributed feedback laser diode;
the grating features are configured as a 1 st order grating, a 2 nd order grating, a 3 rd order grating, a 4 th order grating, or a higher order grating;
the grating features are configured to provide a single frequency operation of the laser diode;
the grating features are configured to provide a spectral width of the electromagnetic radiation characterized by a full width at half maximum (FWHM) of less than 1 nm, less than 0.5 nm, less than 0.2 nm, or less than 0.1 nm; or
the grating features are configured to provide a vertical coupling of the electromagnetic radiation in a direction orthogonal to the one or more n-type gallium and nitrogen containing layers, the one or more light emitting gallium and nitrogen containing layers, and the one or more p-type gallium and nitrogen containing layers.
3 . The method of claim 1 , wherein forming the grating features includes:
planarizing the carrier wafer with the first plurality of dice by depositing a fill layer and using a chemical mechanical polishing (CMP) process to planarize the fill layer, wherein planarizing the carrier wafer includes depositing a stop layer underlying the fill layer, and wherein the CMP process planarized the fill layer and stops at the stop layer, the fill layer including at least one of a nitride, an oxide, a polymer, a spin-on material, or a combination of these materials, and the stop layer including at least one of a nitride, an oxide, a metal, or a polymer;
defining the grating features using one or more lithography steps; and
forming the grating features using one or more etch processes.
4 . The method of claim 1 , further comprising forming an n-contact overlying the grating features of each of the mesa regions, wherein the n-contact includes a gain section for controlling power and a mirror section for injecting current.
5 . The method of claim 1 , further comprising forming an n-contact overlying the grating features of each of the mesa regions, wherein the n-contact includes a gain section for controlling power and front and back mirror sections for injecting current.
6 . The method of claim 1 , further comprising:
transferring a second plurality of dice to the carrier wafer, wherein the second plurality of dice are configured to emit electromagnetic radiation at a second wavelength; and
forming second grating features in one or more n-type gallium and nitrogen containing layers of each of the second plurality of dice.
7 . The method of claim 1 , further comprising:
transferring a second plurality of dice and a third plurality of dice to the carrier wafer, wherein the second plurality of dice are configured to emit electromagnetic radiation at a second wavelength, and the third plurality of dice are configured to emit electromagnetic radiation at a third wavelength; and
processing the carrier wafer with the first plurality of dice, the second plurality of dice, and the third plurality of dice to form an RGB emitting laser diode.
8 . The method of claim 1 , wherein the cavity is configured with an optical waveguide coupled to an amplifier to provide a master-oscillator power amplifier (MOPA) device.
9 . The method of claim 1 , further comprising:
forming an n-side dielectric region overlying the one or more n-type gallium and nitrogen containing layers;
forming n-contacts adjacent to the n-side dielectric region;
forming a p-contact vertically aligned with the n-side dielectric region, the p-contact electrically coupled to the one or more p-type gallium and nitrogen containing layers to provide vertical optical confinement;
forming high resistivity regions on each side of the p-contact to block current flow through adjacent portions of the one or more p-type gallium and nitrogen containing layers; and
forming a p-side ridge aligned with the p-contact to provide lateral optical confinement.
10 . The method of claim 1 , further comprising:
forming an n-side dielectric region overlying the one or more n-type gallium and nitrogen containing layers;
forming n-contacts adjacent to the n-side dielectric region;
forming a transmissive conductive oxide (TCO) vertically aligned with the n-side dielectric region, the TCO electrically coupled to the one or more p-type gallium and nitrogen containing layers to provide vertical optical confinement;
forming high resistivity regions on each side of the TCO to block current flow through adjacent portions of the one or more p-type gallium and nitrogen containing layers; and
forming a p-side ridge aligned with the TCO to provide lateral optical confinement.
11 . The method of claim 1 , further comprising:
forming an n-side dielectric region overlying the one or more n-type gallium and nitrogen containing layers;
forming n-contacts adjacent to the n-side dielectric region;
forming a transmissive conductive oxide (TCO) vertically aligned with the n-side dielectric region, the TCO electrically coupled to the one or more p-type gallium and nitrogen containing layers to provide vertical optical confinement;
forming a p-side ridge aligned with the TCO to provide lateral optical confinement;
forming high resistivity regions in at least one of the one or more p-type gallium and nitrogen containing layers, the high resistivity regions formed on opposite sides of the p-side ridge from the TCO to block current flow through adjacent portions of the one or more p-type gallium and nitrogen containing layers; and
forming sloped sidewalls on the mesa regions so that a top surface area of the one or more n-type gallium and nitrogen containing layers is less than a bottom surface area of the one or more p-type gallium and nitrogen containing layers.
12 . The method of claim 1 , wherein the grating features are configured to provide optical feedback to form a distributed Bragg reflector laser diode.
13 . The method of claim 12 , wherein Bragg gratings are formed on both ends of the cavity.
14 . The method of claim 12 , wherein a coating for a high reflective mirror is disposed on one end of the cavity.
15 . The method of claim 1 , wherein the grating features are configured to provide optical feedback to form a distributed feedback laser diode.
16 . A method for manufacturing an optical device, the method comprising:
providing a carrier wafer;
providing a first substrate having a first surface region;
forming a first gallium and nitrogen containing epitaxial material overlying the first surface region, the first epitaxial material comprising a first release material overlying the first substrate and one or more n-type gallium and nitrogen containing layers, one or more light emitting gallium and nitrogen containing layers comprising an active region configured to emit electromagnetic radiation at a first wavelength, and one or more p-type gallium and nitrogen containing layers overlying the first release material;
patterning the first epitaxial material and forming mesas to form a plurality of first dice arranged in an array;
forming a first interface region overlying the first epitaxial material;
bonding the first interface region of at least a fraction of the plurality of first dice to the carrier wafer to form bonded structures;
releasing the bonded structures to transfer a first plurality of dice to the carrier wafer, the first plurality of dice transferred to the carrier wafer forming mesa regions on the carrier wafer;
forming grating features in a material overlying the one or more n-type gallium and nitrogen containing layers of each of the mesa regions, or in a material overlying the one or more n-type gallium and nitrogen containing layers and in the one or more n-type gallium and nitrogen containing layers of each of the mesa regions; and
forming an optical waveguide in each of the mesa regions, the optical waveguide configured as a cavity to form a laser diode of the electromagnetic radiation; wherein the grating features are configured to provide feedback to the electromagnetic radiation.
17 . The method of claim 16 , wherein the material overlying the one or more n-type gallium and nitrogen containing layers comprises a dielectric or transparent conducive oxide (TCO) material.
18 . The method of claim 16 , wherein the material overlying the one or more n-type gallium and nitrogen containing layers comprises a silicon oxide, silicon nitride, or transparent conducive oxide (TCO) material.
19 . The method of claim 16 , wherein the cavity is configured as a laser diode operating in a 390 nm to 550 nm wavelength range, and wherein at least one of:
the grating features are configured to provide optical feedback to form a distributed feedback laser diode;
the grating features are configured as a 1 st order grating, a 2 nd order grating, a 3 rd order grating, a 4 th order grating, or a higher order grating;
the grating features are configured to provide a single frequency operation of the laser diode;
the grating features are configured to provide a spectral width of the electromagnetic radiation characterized by a full width at half maximum (FWHM) of less than 1 nm, less than 0.5 nm, less than 0.2 nm, or less than 0.1 nm; or
the grating features are configured to provide a vertical coupling of the electromagnetic radiation in a direction orthogonal to the one or more n-type gallium and nitrogen containing layers, the one or more light emitting gallium and nitrogen containing layers, and the one or more p-type gallium and nitrogen containing layers.
20 . The method of claim 16 , wherein forming the grating features includes:
planarizing the carrier wafer with the first plurality of dice by depositing a fill layer and using a chemical mechanical polishing (CMP) process to planarize the fill layer, wherein planarizing the carrier wafer includes depositing a stop layer underlying the fill layer, and wherein the CMP process planarized the fill layer and stops at the stop layer, the fill layer including at least one of a nitride, an oxide, a polymer, a spin-on material, or a combination of these materials, and the stop layer including at least one of a nitride, an oxide, a metal, or a polymer;
defining the grating features using one or more lithography steps; and
forming the grating features using one or more etch processes.
21 . The method of claim 16 , further comprising forming an n-contact overlying the grating features of each of the mesa regions, wherein the n-contact includes a gain section for controlling power and a mirror section for injecting current.
22 . The method of claim 16 , further comprising forming an n-contact overlying the grating features of each of the mesa regions, wherein the n-contact includes a gain section for controlling power and front and back mirror sections for injecting current.
23 . The method of claim 16 , further comprising:
transferring a second plurality of dice to the carrier wafer, wherein the second plurality of dice are configured to emit electromagnetic radiation at a second wavelength;
forming second grating features in a second material overlying the one or more n-type gallium and nitrogen containing layers of each of the second plurality of dice.
24 . The method of claim 16 , further comprising:
transferring a second plurality of dice and a third plurality of dice to the carrier wafer, wherein the second plurality of dice are configured to emit electromagnetic radiation at a second wavelength, and the third plurality of dice are configured to emit electromagnetic radiation at a third wavelength; and
processing the carrier wafer with the first plurality of dice, the second plurality of dice, and the third plurality of dice to form an RGB emitting laser diode.
25 . The method of claim 16 , wherein the cavity is configured with an optical waveguide coupled to an amplifier to provide a master-oscillator power amplifier (MOPA) device.