Method for manufacturing nitride semiconductor laminate, nitride semiconductor laminate, method for inspecting film quality, and method for inspecting semiconductor growing device

Patent metadata

Field	Value
Publication number	US-2021215621-A1
Application number	US-201917055539-A
Country	US
Kind code	A1
Filing date	Apr 8, 2019
Priority date	May 15, 2018
Publication date	Jul 15, 2021
Grant date	—

Abstract

There is provided a method for producing a nitride semiconductor laminate in which a thin film is homoepitaxially grown on a substrate comprising group III nitride semiconductor crystals, the method including: homoepitaxially growing a thin film on a substrate, using the substrate in which a dislocation density on its main surface is 5×106 pieces/cm2 or less, a concentration of oxygen therein is less than 1×1017 at·cm−3, and a concentration of impurities therein other than n-type impurity is less than 1×1017 at·cm−3; and inspecting a film quality of the thin film formed on the substrate, wherein in the inspection of the film quality, the film quality of the thin film is inspected by detecting a deviation of an amount of reflected light at a predetermined wavenumber determined in a range of 1,600 cm−1 or more and 1,700 cm−1 or less in a reflection spectrum obtained by irradiating the thin film on the substrate with infrared light, from an amount of reflected. light at the predetermined wavenumber determined according to a film thickness of the thin film, a carder concentration of the substrate, and a carrier concentration of the thin film.

First claim

1 - 7 . (canceled)

8 . A method for inspecting a film quality for inspecting a film quality of a thin film in a nitride semiconductor laminate obtained by homoepitaxially growing a thin film on a substrate comprising crystals of a group III nitride semiconductor, which is a method for inspecting a film quality of a thin film by detecting a deviation of an amount of reflected light at a predetermined wavenumber determined in a range of 1,600 cm −1 or more and 1,700 cm −1 or less in a reflection spectrum obtained by irradiating the thin film on the substrate with infrared light, from an amount of reflected light at the predetermined wavenumber determined according to a film thickness of the thin film, a carrier concentration of the substrate, and a carrier concentration of the thin film, using the substrate in which a dislocation density on its main surface is 5×10 6 pieces/cm 2 or less, a concentration of oxygen therein is less than 1×10 17 at·cm −3 , and a concentration of impurities therein other than n-type impurity is less than 1×10 17 at·cm −3 ,

9 . (canceled)

10 . A nitride semiconductor laminate, comprising:
a substrate comprising group III nitride semiconductor crystals; and a thin film homoepitaxially grown on the substrate, wherein a dislocation density on a main surface of the substrate is 5×10 6 pieces/cm 2 or less, a concentration of oxygen in the substrate is less than 1×10 17 at·cm −3 , and a concentration of impurities other than n-type impurity in the substrate is less than 1×10 17 at·cm −3 , and
when taking into consideration of a deviation of an amount of reflected light at a predetermined wavenumber in a reflection spectrum obtained by irradiating the thin film on the substrate with infrared light, from an amount of reflected light at the predetermined wavenumber determined according to a film thickness of the thin film, a carrier concentration of the substrate. and a carrier concentration of the thin film, a maximum value of a degree of a deviation in a wavenumber range of 1,600 cm −1 or more and 1,700 cm −1 or less is larger than any of a maximum value of a degree of a deviation in a wavenumber range of 1,500 cm −1 or more and less than 1,600 cm −1 and a maximum value of a degree of a deviation in a wavenumber range of more than 1,700 cm −1 and 1,800 cm −1 or less.

11 . The nitride semiconductor laminate according to claim 10 , wherein the maximum value of the degree of the deviation in the wavenumber range of 1,600 cm −1 or more and 1,700 cm −1 or less is 1% or more and 10% or less as a degree of a difference in intensity reflectance.

12 . A nitride semiconductor laminate, comprising:
a substrate comprising group III nitride semiconductor crystals; and a thin film homoepitaxially grown on the substrate, wherein a dislocation density on a main surface of the substrate is 5×10 6 pieces/cm 2 or less, a concentration of oxygen in the substrate is less than 1×10 17 at·cm −3 , and a concentration of impurities other than n-type impurity in the substrate is less than 1×10 17 at·cm −3 , and
when taking into consideration of a deviation of an amount of reflected light at a predetermined wavenumber in a reflection spectrum obtained by irradiating the thin film on the substrate with infrared light, from an amount of reflected light at the predetermined wavenumber determined according to a film thickness of the thin film, a carrier concentration of the substrate, and a carrier concentration of the thin film, any of a maximum value of a degree of the deviation in a wavenumber range of 1,600 cm −1 or more and 1,700 cm −1 or less, a maximum value of a degree of a deviation in a wavenumber range of 1,500 cm −1 or more and less than 1,600 cm −1 and a maximum value of a degree of a deviation in a wavenumber range of more than 1,700 cm −1 and 1,800 cm −1 or less, is less than 1% as a degree of a difference in intensity reflectance.

13 . The nitride semiconductor laminate according to claim 10 , wherein when the maximum value of the degree of the deviation in the wavenumber range of 1,600 cm −1 or more and 1,700 cm −1 or less is acquired at a plurality of positions on the main surface of the thin film, a maximum value is 1.5 times or less of a minimum value among the plurality of acquired maximum values.

14 . The nitride semiconductor laminate according to claim 10 , wherein an absorption coefficient α in a wavelength range of at least 1 μm or more and 3.3 μm or less is approximated by equation (1) by a method of least squares, and
an error of the measured absorption coefficient at a wavelength of 2 μ with respect to the absorption coefficient α obtained from the equation (1) is within ±0.1α,
where a wavelength is λ (μm), an absorption coefficient of the substrate at 27° C. is α (cm −1 ), a carrier concentration in the substrate is Ne (cm −3 ), and K and a are constants.

15 . The nitride semiconductor laminate according to claim 10 , wherein a crystal of the group III nitride semiconductor is a gallium nitride crystal.

16 - 17 . (canceled)

18 . The nitride semiconductor laminate according to claim 12 , wherein when the maximum value of the degree of the deviation in the wavenumber range of 1,600 cm −1 or more and 1,700 cm −1 or less is acquired at a plurality of positions on the main surface of the thin film, a maximum value is 1.5 times or less of a minimum value among the plurality of acquired maximum values.

19 . The nitride semiconductor laminate according to claim 12 , wherein an absorption coefficient α in a wavelength range of at least 1 μm or more and 3.3 μm or less is approximated by equation (1) by a method of least squares, and
an error of the measured absorption coefficient at a wavelength of 2 μ with respect to the absorption coefficient α obtained from the equation (1) is within ±0.1α,
where a wavelength is λ (μm), an absorption coefficient of the substrate at 27° C. is α (cm −1 ), a carrier concentration in the substrate is Ne (cm −3 ), and K and a are constants.

20 . The nitride semiconductor laminate according to claim 12 , wherein a crystal of the group III nitride semiconductor is a gallium nitride crystal.

Assignees

• Sciocs Co Ltd
• Sumitomo Chemical Co

Inventors

• Horikiri Fumimasa

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P14/3416

  Nitrides · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10P14/3442

  N-type · CPC title

• H10P14/2908

  Nitrides · CPC title