Patent
US 10,644,188Laser Epitaxial Lift-Off of High Efficiency Solar Cell
John Farah
US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 10,644,188Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 Thin IMM₃J solar cell on polyimide substrate 50 p m thick;
FIG. 2B Concept 2 Laser ablation of embedded epitaxial release layer;
FIG. 3 Epitaxial layer lifted-off GaAs wafer at-140* C on Kapton sheet (brown) 50 m thick;
FIG. 4 GaAs (110) wafer lifted on Kapton (right), base wafer (left);
FIG. 5 GaAs (100) wafer lifted on Kapton (right), base wafer (left);
FIG. 6 AFM roughness measurements of GaAs (110) cleaved surface;
FIG. 7 Solar cell sandwiched between Kapton/adhesive layer on top and SiGe release layer on GaAs wafer;
FIG. 8 Non-inverted triple junction solar cell, SiGe bottom cell;
FIG. 9 Inverted metamorphic triple junction (IMM₃J) solar cell on SiGe release layer;
FIG. 10 Inverted lattice matched triple junction (ILM₃J) solar cell on SiGe release layer;
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 13 Solar cell with inset showing details of InGaP protection layers;
FIG. 14 Single photon absorption coefficients of Ge and GaAs;
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-20 Canceled
Canceled
A method for separating an epitaxially grown layer from a GaAs growth sub s trate comprising: growing an epitaxial sacrificial layer between said epitaxially grown layer and said GaAs substrate having substantially the same lattice constant, irr adiating said substrate, epitaxially grown layer and sacrificial layer with electromagnetic radiation emanating from a pulsed Nd:YAG laser emitting in the NIR at a wavelength of about 1.064 gy m, having a pulse width about 5 nanoseconds and energy about 2.4 milli-Joules per pulse and energy density about 300 mJ/cm 2, wherein said electromagnetic radiation is predominantly absorbed in said sacrificial layer, breaking atomic bonds in said sacrificial layer with said electromagnetic radiation, thereby separating said epitaxially grown layer from said GaAs growth substrate. New
The method of claim 21 further comprising the step of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said epitaxially grown layer and said GaAs substrate, to said epitaxial layer, Cooling the laminate in liquid nitrogen, wherein said polyimide tape assists from said growth substrate. New
A method for separating an epitaxially grown layer from a GaAs growth substrate consisting of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate and said epitaxial layer, to said epitaxial layer, Choosing a thickness of said layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said epitaxially grown layer from said growth substrate. New
The method of claim 22 wherein said polyimide tape is a stressor layer. New
The method of claim 22 wherein said polyimide tape is a permanent carrier of said epitaxially grown layer after separation. New
The method of claim 22 wherein said epitaxially grown layer contains a light emitting diode (LED) or an inverted multi-junction solar cell. New
The method of claim 22 wherein the thickness of said polyimide tape is about 50 gym. New
A method of thinning a SiC or GaN substrate by separating a first layer from said substrate consisting of: Laminating a second layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate, to said first laye r, Choosing a thickness of said second layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said first layer from said substrate. New
The method of claim 28 wherein said laminate comprises multiple layers of polyimide sheet and acrylic adhesive. New
The method of claim 28 wherein said first layer comprises an epitaxially grown layer. New
Layer stacks claimed or described, ordered top of device to substrate.
light emitting diode (LED)
inverted multi-junction solar cell (IMM/ILM)
Materials described outside the worked examples.
GaAs substrate
GaAs
epitaxial sacrificial layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
AFM average roughness of GaAs (110) cleaved surface | 0.059 nm | GaAs |
CTE of polyimide (Kapton) |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,644,188Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 Thin IMM₃J solar cell on polyimide substrate 50 p m thick;
FIG. 2B Concept 2 Laser ablation of embedded epitaxial release layer;
FIG. 3 Epitaxial layer lifted-off GaAs wafer at-140* C on Kapton sheet (brown) 50 m thick;
FIG. 4 GaAs (110) wafer lifted on Kapton (right), base wafer (left);
FIG. 5 GaAs (100) wafer lifted on Kapton (right), base wafer (left);
FIG. 6 AFM roughness measurements of GaAs (110) cleaved surface;
FIG. 7 Solar cell sandwiched between Kapton/adhesive layer on top and SiGe release layer on GaAs wafer;
FIG. 8 Non-inverted triple junction solar cell, SiGe bottom cell;
FIG. 9 Inverted metamorphic triple junction (IMM₃J) solar cell on SiGe release layer;
FIG. 10 Inverted lattice matched triple junction (ILM₃J) solar cell on SiGe release layer;
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 13 Solar cell with inset showing details of InGaP protection layers;
FIG. 14 Single photon absorption coefficients of Ge and GaAs;
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-20 Canceled
Canceled
A method for separating an epitaxially grown layer from a GaAs growth sub s trate comprising: growing an epitaxial sacrificial layer between said epitaxially grown layer and said GaAs substrate having substantially the same lattice constant, irr adiating said substrate, epitaxially grown layer and sacrificial layer with electromagnetic radiation emanating from a pulsed Nd:YAG laser emitting in the NIR at a wavelength of about 1.064 gy m, having a pulse width about 5 nanoseconds and energy about 2.4 milli-Joules per pulse and energy density about 300 mJ/cm 2, wherein said electromagnetic radiation is predominantly absorbed in said sacrificial layer, breaking atomic bonds in said sacrificial layer with said electromagnetic radiation, thereby separating said epitaxially grown layer from said GaAs growth substrate. New
The method of claim 21 further comprising the step of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said epitaxially grown layer and said GaAs substrate, to said epitaxial layer, Cooling the laminate in liquid nitrogen, wherein said polyimide tape assists from said growth substrate. New
A method for separating an epitaxially grown layer from a GaAs growth substrate consisting of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate and said epitaxial layer, to said epitaxial layer, Choosing a thickness of said layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said epitaxially grown layer from said growth substrate. New
The method of claim 22 wherein said polyimide tape is a stressor layer. New
The method of claim 22 wherein said polyimide tape is a permanent carrier of said epitaxially grown layer after separation. New
The method of claim 22 wherein said epitaxially grown layer contains a light emitting diode (LED) or an inverted multi-junction solar cell. New
The method of claim 22 wherein the thickness of said polyimide tape is about 50 gym. New
A method of thinning a SiC or GaN substrate by separating a first layer from said substrate consisting of: Laminating a second layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate, to said first laye r, Choosing a thickness of said second layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said first layer from said substrate. New
The method of claim 28 wherein said laminate comprises multiple layers of polyimide sheet and acrylic adhesive. New
The method of claim 28 wherein said first layer comprises an epitaxially grown layer. New
Layer stacks claimed or described, ordered top of device to substrate.
light emitting diode (LED)
inverted multi-junction solar cell (IMM/ILM)
Materials described outside the worked examples.
GaAs substrate
GaAs
epitaxial sacrificial layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
AFM average roughness of GaAs (110) cleaved surface | 0.059 nm | GaAs |
CTE of polyimide (Kapton) |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,644,188Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 Thin IMM₃J solar cell on polyimide substrate 50 p m thick;
FIG. 2B Concept 2 Laser ablation of embedded epitaxial release layer;
FIG. 3 Epitaxial layer lifted-off GaAs wafer at-140* C on Kapton sheet (brown) 50 m thick;
FIG. 4 GaAs (110) wafer lifted on Kapton (right), base wafer (left);
FIG. 5 GaAs (100) wafer lifted on Kapton (right), base wafer (left);
FIG. 6 AFM roughness measurements of GaAs (110) cleaved surface;
FIG. 7 Solar cell sandwiched between Kapton/adhesive layer on top and SiGe release layer on GaAs wafer;
FIG. 8 Non-inverted triple junction solar cell, SiGe bottom cell;
FIG. 9 Inverted metamorphic triple junction (IMM₃J) solar cell on SiGe release layer;
FIG. 10 Inverted lattice matched triple junction (ILM₃J) solar cell on SiGe release layer;
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 13 Solar cell with inset showing details of InGaP protection layers;
FIG. 14 Single photon absorption coefficients of Ge and GaAs;
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-20 Canceled
Canceled
A method for separating an epitaxially grown layer from a GaAs growth sub s trate comprising: growing an epitaxial sacrificial layer between said epitaxially grown layer and said GaAs substrate having substantially the same lattice constant, irr adiating said substrate, epitaxially grown layer and sacrificial layer with electromagnetic radiation emanating from a pulsed Nd:YAG laser emitting in the NIR at a wavelength of about 1.064 gy m, having a pulse width about 5 nanoseconds and energy about 2.4 milli-Joules per pulse and energy density about 300 mJ/cm 2, wherein said electromagnetic radiation is predominantly absorbed in said sacrificial layer, breaking atomic bonds in said sacrificial layer with said electromagnetic radiation, thereby separating said epitaxially grown layer from said GaAs growth substrate. New
The method of claim 21 further comprising the step of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said epitaxially grown layer and said GaAs substrate, to said epitaxial layer, Cooling the laminate in liquid nitrogen, wherein said polyimide tape assists from said growth substrate. New
A method for separating an epitaxially grown layer from a GaAs growth substrate consisting of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate and said epitaxial layer, to said epitaxial layer, Choosing a thickness of said layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said epitaxially grown layer from said growth substrate. New
The method of claim 22 wherein said polyimide tape is a stressor layer. New
The method of claim 22 wherein said polyimide tape is a permanent carrier of said epitaxially grown layer after separation. New
The method of claim 22 wherein said epitaxially grown layer contains a light emitting diode (LED) or an inverted multi-junction solar cell. New
The method of claim 22 wherein the thickness of said polyimide tape is about 50 gym. New
A method of thinning a SiC or GaN substrate by separating a first layer from said substrate consisting of: Laminating a second layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate, to said first laye r, Choosing a thickness of said second layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said first layer from said substrate. New
The method of claim 28 wherein said laminate comprises multiple layers of polyimide sheet and acrylic adhesive. New
The method of claim 28 wherein said first layer comprises an epitaxially grown layer. New
Layer stacks claimed or described, ordered top of device to substrate.
light emitting diode (LED)
inverted multi-junction solar cell (IMM/ILM)
Materials described outside the worked examples.
GaAs substrate
GaAs
epitaxial sacrificial layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
AFM average roughness of GaAs (110) cleaved surface | 0.059 nm | GaAs |
CTE of polyimide (Kapton) |
Related documents with shared materials, methods, properties, or citations.
Patent
Atlas literature
Patent
US 10,644,188Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 Thin IMM₃J solar cell on polyimide substrate 50 p m thick;
FIG. 2B Concept 2 Laser ablation of embedded epitaxial release layer;
FIG. 3 Epitaxial layer lifted-off GaAs wafer at-140* C on Kapton sheet (brown) 50 m thick;
FIG. 4 GaAs (110) wafer lifted on Kapton (right), base wafer (left);
FIG. 5 GaAs (100) wafer lifted on Kapton (right), base wafer (left);
FIG. 6 AFM roughness measurements of GaAs (110) cleaved surface;
FIG. 7 Solar cell sandwiched between Kapton/adhesive layer on top and SiGe release layer on GaAs wafer;
FIG. 8 Non-inverted triple junction solar cell, SiGe bottom cell;
FIG. 9 Inverted metamorphic triple junction (IMM₃J) solar cell on SiGe release layer;
FIG. 10 Inverted lattice matched triple junction (ILM₃J) solar cell on SiGe release layer;
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 13 Solar cell with inset showing details of InGaP protection layers;
FIG. 14 Single photon absorption coefficients of Ge and GaAs;
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
1-20 Canceled
Canceled
A method for separating an epitaxially grown layer from a GaAs growth sub s trate comprising: growing an epitaxial sacrificial layer between said epitaxially grown layer and said GaAs substrate having substantially the same lattice constant, irr adiating said substrate, epitaxially grown layer and sacrificial layer with electromagnetic radiation emanating from a pulsed Nd:YAG laser emitting in the NIR at a wavelength of about 1.064 gy m, having a pulse width about 5 nanoseconds and energy about 2.4 milli-Joules per pulse and energy density about 300 mJ/cm 2, wherein said electromagnetic radiation is predominantly absorbed in said sacrificial layer, breaking atomic bonds in said sacrificial layer with said electromagnetic radiation, thereby separating said epitaxially grown layer from said GaAs growth substrate. New
The method of claim 21 further comprising the step of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said epitaxially grown layer and said GaAs substrate, to said epitaxial layer, Cooling the laminate in liquid nitrogen, wherein said polyimide tape assists from said growth substrate. New
A method for separating an epitaxially grown layer from a GaAs growth substrate consisting of: Laminating a layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate and said epitaxial layer, to said epitaxial layer, Choosing a thickness of said layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said epitaxially grown layer from said growth substrate. New
The method of claim 22 wherein said polyimide tape is a stressor layer. New
The method of claim 22 wherein said polyimide tape is a permanent carrier of said epitaxially grown layer after separation. New
The method of claim 22 wherein said epitaxially grown layer contains a light emitting diode (LED) or an inverted multi-junction solar cell. New
The method of claim 22 wherein the thickness of said polyimide tape is about 50 gym. New
A method of thinning a SiC or GaN substrate by separating a first layer from said substrate consisting of: Laminating a second layer of polyimide tape comprising a layer of acrylic adhesive having a higher coefficient of thermal expansion than said substrate, to said first laye r, Choosing a thickness of said second layer of polyimide tape, Cooling the laminate in liquid nitrogen, thereby driving a crack in said substrate by thermal stresses due to the difference between the coefficients of thermal expansion of said substrate and said polyimide tape, thus separating said first layer from said substrate. New
The method of claim 28 wherein said laminate comprises multiple layers of polyimide sheet and acrylic adhesive. New
The method of claim 28 wherein said first layer comprises an epitaxially grown layer. New
Layer stacks claimed or described, ordered top of device to substrate.
light emitting diode (LED)
inverted multi-junction solar cell (IMM/ILM)
Materials described outside the worked examples.
GaAs substrate
GaAs
epitaxial sacrificial layer
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
AFM average roughness of GaAs (110) cleaved surface | 0.059 nm | GaAs |
CTE of polyimide (Kapton) |
Related documents with shared materials, methods, properties, or citations.
epitaxially grown III-V layer
polyimide tape (Kapton)
acrylic adhesive (Pyralux)
SiC substrate
SiC
GaN substrate
GaN
SiGe release layer
SiGe
InGaP etch stop layer
InGaP
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
| 16–20 ppm/°C |
polyimide tape (Kapton) |
CTE of GaAs | 5–6 ppm/°C | GaAs |
Thickness | 0.2–0.35 cm | — |
Thickness | 50–60 cm | — |
Quantum simulations of ultrafast optical spectroscopy of semiconductors on digital quantum computers in the semi-classical approximation
epitaxially grown III-V layer
polyimide tape (Kapton)
acrylic adhesive (Pyralux)
SiC substrate
SiC
GaN substrate
GaN
SiGe release layer
SiGe
InGaP etch stop layer
InGaP
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
| 16–20 ppm/°C |
polyimide tape (Kapton) |
CTE of GaAs | 5–6 ppm/°C | GaAs |
Thickness | 0.2–0.35 cm | — |
Thickness | 50–60 cm | — |
Quantum simulations of ultrafast optical spectroscopy of semiconductors on digital quantum computers in the semi-classical approximation
epitaxially grown III-V layer
polyimide tape (Kapton)
acrylic adhesive (Pyralux)
SiC substrate
SiC
GaN substrate
GaN
SiGe release layer
SiGe
InGaP etch stop layer
InGaP
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
| 16–20 ppm/°C |
polyimide tape (Kapton) |
CTE of GaAs | 5–6 ppm/°C | GaAs |
Thickness | 0.2–0.35 cm | — |
Thickness | 50–60 cm | — |
Quantum simulations of ultrafast optical spectroscopy of semiconductors on digital quantum computers in the semi-classical approximation
epitaxially grown III-V layer
polyimide tape (Kapton)
acrylic adhesive (Pyralux)
SiC substrate
SiC
GaN substrate
GaN
SiGe release layer
SiGe
InGaP etch stop layer
InGaP
FIG. 11 Solar cell with quantum well absorption layer in SiGe release layer; Fig. 12 Solar cell with SiGe release layer sandwiched between GaAs buffer layers …
FIG. 15 Single-shot melting and ablation thresholds of Ge and GaAs for femtosecond pulses at nm; Fig. 16A Two-photon absorption coefficients at 300 K for GaAs; …
| 16–20 ppm/°C |
polyimide tape (Kapton) |
CTE of GaAs | 5–6 ppm/°C | GaAs |
Thickness | 0.2–0.35 cm | — |
Thickness | 50–60 cm | — |
Quantum simulations of ultrafast optical spectroscopy of semiconductors on digital quantum computers in the semi-classical approximation