Wafer level epitaxial film and method of making the same

Abstract

The application belongs to the technical field of semiconductor material thin films, and discloses a wafer-level epitaxial thin film and a preparation method thereof. The preparation method of the doped heteroepitaxial thin film comprises the following steps: placing a substrate into a vacuum reaction cavity of an atomic layer deposition device, heating to a preset temperature, and then performing functionalization treatment on the substrate by using an M source; sequentially pulsing an A source and the M source into the vacuum reaction cavity, and then repeatedly pulsing the A source and the M source; then pulsing a precursor source of a doping atom and the M source; sequentially pulsing the A source and the M source, and then repeatedly pulsing the A source and the M source to obtain an A x M y thin film layer; the above process is repeated; or the A source and the M source are sequentially pulsed, and then the A source and the M source are repeatedly pulsed to obtain an A x M y thin film; then annealing treatment is performed to obtain a wafer-level epitaxial thin film. The doping concentration of the doping atom is adjusted by adjusting the relative layer number of the two molecular layers, so that atomic layer doping of the doping element in the thin film is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor material thin film, and particularly to a wafer-level epitaxial thin film and a preparation method thereof. BACKGROUND

[0002] With the rapid development of modern industries such as electric vehicles, 5G, and Internet of Things, the demand for high-performance and high-power semiconductor devices is increasingly urgent. Third-generation wide-bandgap semiconductor materials such as gallium nitride have advantages such as high breakdown field strength and low material loss, and have been widely studied in high-power devices. However, due to the high cost of high-quality substrate materials, gallium nitride power devices are not suitable for mass production, which seriously limits the development of their industrial applications.

[0003] There are many methods for preparing thin films such as gallium nitride, such as molecular beam epitaxy, halogen vapor phase epitaxy, pulsed laser deposition, and metal organic chemical vapor deposition. These thin film preparation methods not only require high temperatures, but also have poor uniformity of the prepared thin films, which cannot fully exhibit the performance of the materials when preparing devices. Compared with these methods, atomic layer deposition has great advantages in precise control of thin film thickness, uniformity of large area, and low-temperature preparation of thin films. However, in the current process of atomic layer deposition of thin films, due to process problems and other issues, crystal defects are easily produced, which seriously affects the performance of doped thin film devices. SUMMARY

[0004] The present application aims to provide a wafer-level epitaxial thin film and a preparation method thereof to solve the problems in the prior art.

[0005] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0006] The present application provides a preparation method of a wafer-level epitaxial thin film, comprising the following steps:

[0007] (1) placing a substrate into a vacuum reaction chamber of an atomic layer deposition device, heating to a preset temperature, and then performing functionalization treatment on the substrate using an M source;

[0008] (2) sequentially pulsing an A source, an M source, and then repeating the pulsing of the A source and the M source in the vacuum reaction chamber to obtain an A x M y thin film layer; then pulsing a dopant atom precursor source and an M source to obtain a dopant atom layer; sequentially pulsing an A source and an M source, and then repeating the pulsing of the A source and the M source to obtain an A x M y thin film layer; repeating the above process as a cycle to obtain a thin film;

[0009] or sequentially pulsing the A source and the M source into the vacuum reaction cavity, and then repeating the pulsing of the A source and the M source to obtain the A x M y thin film

[0010] (3) annealing the doped thin film or the A x M y thin film to obtain a wafer-level epitaxial nitride / oxide thin film

[0011] A x M y The M source comprises one of gallium oxide, gallium nitride, aluminum nitride, hafnium oxide, silicon oxide.

[0012] Preferably, in the above method for preparing a wafer-level epitaxial thin film, the substrate in the step (1) is a silicon substrate or a sapphire substrate, the preset temperature in the step (1) is 150-500°C, the pressure in the vacuum reaction cavity in the step (1) is 500-1500 Pa, and the functionalization treatment time in the step (1) is 120-600 s.

[0013] Preferably, in the above method for preparing a wafer-level epitaxial thin film, the A x M y source is trimethylgallium or triethylgallium; when the M source is gallium nitride, the A source is trimethylaluminum or triethylaluminum; when the M source is aluminum nitride, the A source is tetrakis(dimethylamine)hafnium or tris(dimethylamino)cyclopentadienylhafnium; and when the M source is hafnium oxide, the A source is tris(dimethylamino)silane or bis(diethylamino)silane. x M y source is trimethylaluminum or triethylaluminum; when the M source is aluminum nitride, the A source is tetrakis(dimethylamine)hafnium or tris(dimethylamino)cyclopentadienylhafnium; and when the M source is hafnium oxide, the A source is tris(dimethylamino)silane or bis(diethylamino)silane. x M y source is trimethylaluminum or triethylaluminum; when the M source is aluminum nitride, the A source is tetrakis(dimethylamine)hafnium or tris(dimethylamino)cyclopentadienylhafnium; and when the M source is hafnium oxide, the A source is tris(dimethylamino)silane or bis(diethylamino)silane. x M y source is trimethylaluminum or triethylaluminum; when the M source is aluminum nitride, the A source is tetrakis(dimethylamine)hafnium or tris(dimethylamino)cyclopentadienylhafnium; and when the M source is hafnium oxide, the A source is tris(dimethylamino)silane or bis(diethylamino)silane.

[0014] Preferably, in the above method for preparing a wafer-level epitaxial thin film, the M source in the step (2) is a nitrogen source or an oxygen source; the nitrogen source is N2 plasma, NH3 or NH3 plasma, and the oxygen source is O2 plasma or ozone.

[0015] Preferably, in the above-mentioned wafer-level epitaxial film preparation method, the doping atom in step (2) is silicon, nitrogen, sulfur, phosphorus, aluminum, copper, tin, titanium or tantalum, when the doping atom is silicon, the precursor source of the doping atom is tris(dimethylamino)silane or bis(diethylamino)silane; when the doping atom is nitrogen, the precursor source of the doping atom is NH3; when the doping atom is sulfur, the precursor source of the doping atom is H2S; when the doping atom is phosphorus, the precursor source of the doping atom is PH3 plasma, trimethylphosphine or triethylphosphine; when the doping atom is aluminum, the precursor source of the doping atom is trimethylaluminum, triethylaluminum or dimethylisopropoxyaluminum; when the doping atom is copper, the precursor source of the doping atom is bis(dimethylamine-2-propanol)copper; when the doping atom is titanium, the precursor source of the doping atom is titanium tetraisopropoxide, titanium tetraethoxide or titanium tetrakis(dimethylamide); when the doping atom is tantalum, the precursor source of the doping atom is ethoxy tantalum, pentakis(dimethylamino) tantalum or tris(diethylamino) tert-butanoyl amine tantalum; and when the doping atom is tin, the precursor source of the doping atom is tetra(dimethylamine) tin.

[0016] Preferably, in the above-mentioned wafer-level epitaxial film preparation method, the pulse time of the A source in step (2) is independently 0.1-0.4 s, the carrier gas flow of the A source is independently 100-300 sccm, and the carrier gas of the A source is independently N2 or Ar; the pulse time of the precursor source of the doping atom in step (2) is 0.1-0.5 s, the carrier gas flow of the precursor source of the doping atom is 100-300 sccm, and the carrier gas of the precursor source of the doping atom is N2 or Ar; and the pulse time of the M source in step (2) is independently 3-60 s.

[0017] Preferably, in the above-mentioned wafer-level epitaxial film preparation method, the doping film or A x M y The total thickness of the film is independently 5-1000 nm.

[0018] Preferably, in the above-mentioned wafer-level epitaxial film preparation method, the annealing treatment in step (3) is performed at a temperature of 350-1100 ℃ for 30-120 min at a temperature rising rate of 5-10 ℃ / min.

[0019] The application further provides a wafer-level epitaxial film prepared by the above-mentioned wafer-level epitaxial film preparation method.

[0020] According to the above technical solution, compared with the prior art, the application has the following beneficial effects:

[0021] (1) The application provides a growth method of high-quality hetero-epitaxial oxide / nitride films with precisely regulated doping atom (such as Si) concentration, which is based on the characteristics of atomic layer deposition (ALD) that single atomic layer can be grown in a single layer, and a layer of molecules (such as SiO2) is grown between several film molecular layers, the doping concentration of the doping atom is regulated by adjusting the relative layer number of the two kinds of molecular layers, so as to realize atomic layer doping of the doping element in the oxide / nitride film.

[0022] (2) The wafer-level atomic doping hetero-epitaxial oxide / nitride film prepared by ALD has excellent large-area uniformity and thickness controllability, high process repeatability and few defects.

[0023] (3) The pure-phase gallium oxide film prepared by ALD has good lattice matching degree with the substrate, the prepared film is almost single-phase, and the uniformity is very good, and different phase pure-phase gallium oxide films can be prepared under different deposition and annealing conditions. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description.

[0025] Figure 1 It is a process diagram of the film growth method in the application;

[0026] Figure 2 It is a process diagram of the film growth method in Example 1;

[0027] Figure 3 It is an XRD spectrum of the wafer-level Si-doped β-Ga2O3 film in Example 1 and Example 2;

[0028] Figure 4 It is an XRD spectrum of the wafer-level α-Ga2O3 film in Example 4. DETAILED DESCRIPTION

[0029] The application provides a preparation method of wafer-level epitaxial film, which comprises the following steps:

[0030] (1) Put the substrate into a vacuum reaction chamber of an atomic layer deposition device, heat to a preset temperature, and then perform functionalization treatment on the substrate by using a M source;

[0031] (2) Pulse A source, M source, and then repeat the pulse A source, M source in the vacuum reaction chamber, to obtain A x M y film layer; then pulse the precursor source of the doping atom, M source, to obtain the doping atom layer; then pulse A source, M source, and then repeat the pulse A source, M source, to obtain A x M yThin film layer; repeat the above process as a cycle to obtain a doped thin film;

[0032] Or in the vacuum reaction cavity, pulse A source, M source, and then repeat the pulse A source, M source, to obtain A x M y Thin film;

[0033] (3) The doped thin film or A x M y Thin film is annealed to obtain wafer-level epitaxial nitride / oxide thin film.

[0034] In the present application, the substrate in step (1) is preferably a silicon substrate or a sapphire substrate, more preferably a sapphire substrate.

[0035] In the present application, the substrate in step (1) also includes a pretreatment process, specifically: first, rinse the substrate with water, then place the substrate in an acetone solution, and oscillate the substrate in an ultrasonic oscillator for 30 min, then place the substrate in water, and oscillate the substrate in an ultrasonic oscillator for 15 min, finally, ultrasonic clean with 0.5% hydrofluoric acid solution for 30 s, then rinse with water for 3 min, and dry with high-purity nitrogen.

[0036] In the present application, the preset temperature in step (1) is preferably 150-500°C, further preferably 225-450°C, and more preferably 283-400°C; the pressure in the vacuum reaction cavity in step (1) is preferably 500-1500 Pa, further preferably 658-1255 Pa, and more preferably 725-1100 Pa; the functionalization treatment time in step (1) is preferably 120-600 s, further preferably 150-543 s, and more preferably 246-425 s.

[0037] In the present application, the specific process of sequentially pulsing A source, M source, and then repeating the pulse A source, M source in step (2) is: pulse A source into the vacuum reaction cavity, then purge with nitrogen or argon, then pulse M source, then purge with nitrogen or argon, and then repeat the above process; the purging time is independently preferably 4-30 s, further preferably 8-26 s, and more preferably 13-20 s.

[0038] In the present application, the A x M y In the present application, the A

[0039] In the present application, the A x M yFor gallium oxide or gallium nitride, the A source is preferably trimethyl gallium or triethyl gallium, more preferably trimethyl gallium; A x M y For aluminum nitride, the A source is preferably trimethyl aluminum or triethyl aluminum, more preferably triethyl aluminum; A x M y For hafnium oxide, the A source is preferably tetrakis(dimethylamine) hafnium or tris(dimethylamido) cyclopentadienyl hafnium, more preferably tris(dimethylamido) cyclopentadienyl hafnium; A x M y For silicon oxide, the A source is preferably tris(dimethylamino) silane or bis(diethylamino) silane.

[0040] In the present application, when the A source in step (2) is trimethyl aluminum or triethyl aluminum, a holding treatment is further included before pulsing, and the holding temperature is 15-30°C.

[0041] In the present application, the M source in step (2) is preferably a nitrogen source or an oxygen source, more preferably an oxygen source; the nitrogen source is preferably N2 plasma, NH3 or NH3 plasma, further preferably N2 plasma or NH3, more preferably N2 plasma; the oxygen source is preferably O2 plasma or ozone, more preferably O2 plasma; the power of the O2 plasma is independently preferably 300-2500 W, further preferably 500-2000 W, more preferably 800-1500 W; the power of the N2 plasma is 500-3000 W, further preferably 700-2500 W, more preferably 1150-1800 W; the power of the NH3 plasma is 200-1500 W, further preferably 500-1200 W, more preferably 750-1000 W.

[0042] In the present application, the specific formation process of the doped atomic layer in step (2) is: first pulsing a precursor source of the doping atom, then purging with nitrogen or argon, then pulsing the M source, and then purging with nitrogen or argon; obtaining a doped atomic layer; the purging time is independently preferably 4-30 s, further preferably 8-26 s, more preferably 13-20 s.

[0043] In the present application, the doping atom in step (2) is preferably silicon, nitrogen, sulfur, phosphorus, aluminum, copper, tin, titanium or tantalum, further preferably silicon, nitrogen, titanium or tantalum, more preferably silicon or tantalum;

[0044] When the doping atom is silicon, the precursor source of the doping atom is preferably tris(dimethylamino) silane or bis(diethylamino) silane, more preferably bis(diethylamino) silane;

[0045] When the doping atom is nitrogen, the precursor source of the doping atom is preferably NH3;

[0046] when the doping atom is sulfur, the precursor source of the doping atom is preferably H2S;

[0047] when the doping atom is phosphorus, the precursor source of the doping atom is preferably PH3plasma, trimethylphosphine or triethylphosphine, further preferably PH3plasma or triethylphosphine, and more preferably PH3plasma;

[0048] when the doping atom is aluminum, the precursor source of the doping atom is preferably trimethylaluminum, triethylaluminum or dimethylisopropoxyaluminum, further preferably trimethylaluminum or dimethylisopropoxyaluminum, and more preferably trimethylaluminum;

[0049] when the doping atom is copper, the precursor source of the doping atom is preferably bis(dimethylamine-2-propanol)copper;

[0050] when the doping atom is tin, the precursor source of the doping atom is preferably tetra(dimethylamine)tin;

[0051] when the doping atom is titanium, the precursor source of the doping atom is preferably tetraisopropyltitanium, tetraethoxytitanium or tetra(dimethylamino)titanium, further preferably tetraisopropyltitanium or tetraethoxytitanium, and more preferably tetraisopropyltitanium;

[0052] when the doping atom is tantalum, the precursor source of the doping atom is preferably ethoxytantalum, penta(dimethylamino)tantalum or tris(diethylamino)tert-butanato tantalum, further preferably ethoxytantalum or penta(dimethylamino)tantalum, and more preferably penta(dimethylamino)tantalum.

[0053] In the present application, when the doping atom in step (2) is tetraisopropyltitanium, tetraethoxytitanium or tetra(dimethylamino)titanium, a heat preservation treatment is further included before the pulsing, and the temperature of the heat preservation is 15-30℃.

[0054] In the present application, the pulsing time of the A source in step (2) is independently preferably 0.1-0.4s, further preferably 0.15-0.35s, and more preferably 0.2-0.28s; the carrier gas flow of the A source is independently preferably 100-300sccm, further preferably 125-285sccm, and more preferably 180-220sccm; and the carrier gas of the A source is independently preferably N2or Ar, and more preferably N2.

[0055] In the present application, the pulse time of the precursor source of the doping atom in step (2) is preferably 0.1-0.5 s, further preferably 0.18-0.45 s, and more preferably 0.25-0.3 s; the carrier gas flow of the precursor source of the doping atom is preferably 100-300 sccm, further preferably 125-285 sccm, and more preferably 180-220 sccm; and the carrier gas of the precursor source of the doping atom is preferably N2 or Ar, and more preferably N2.

[0056] In the present application, the pulse time of the M source in step (2) is independently preferably 3-60 s, further preferably 10-55 s, and more preferably 22-45 s.

[0057] In the present application, the total thickness of the thin film in step (2) is independently preferably 5-1000 nm, further preferably 50-945 nm, and more preferably 250-755 nm. x M y The total thickness of the thin film is independently preferably 5-1000 nm, further preferably 50-945 nm, and more preferably 250-755 nm.

[0058] In the present application, the annealing treatment in step (3) is performed at a temperature of 350-1100 ℃, further preferably 400-1000 ℃, and more preferably 550-850 ℃, at a rate of 5-10 ℃ / min, further preferably 5.5-9 ℃ / min, and more preferably 6-8 ℃ / min, for 30-120 min, further preferably 45-105 min, and more preferably 60-85 min.

[0059] The present application also provides a wafer-level epitaxial thin film prepared by the above method.

[0060] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0061] Embodiment 1

[0062] (1) using (0001) oriented sapphire as a substrate, cleaning the (0001) oriented sapphire substrate, the specific process is: first, using deionized water to flush the (0001) oriented sapphire substrate, then put it into the acetone solution, oscillate and clean the (0001) oriented sapphire substrate in the ultrasonic oscillator for 30 min, then put the (0001) oriented sapphire substrate into the deionized water, oscillate and clean the (0001) oriented sapphire substrate in the ultrasonic oscillator for 15 min, finally, use 0.5% hydrofluoric acid solution to ultrasonic clean for 30 s, then flush with deionized water for 3 min, and finally dry with high-purity nitrogen;

[0063] (2) put the cleaned (0001) oriented sapphire substrate into the vacuum reaction chamber of the atomic layer deposition equipment, heat to the preset temperature 280℃, then use O2 plasma to functionalize the substrate for 600 s, the power of O2 plasma is 500 W;

[0064] (3) using trimethyl gallium as gallium source, O2 plasma as oxygen source, bis-diethylaminosilane as silicon source, and N2 as purge gas;

[0065] (4) pulse trimethyl gallium into the vacuum reaction chamber, after the pulse is over, use N2 to purge, then pulse O2 plasma, after the pulse is over, use N2 to purge, repeat the above process 5 times to obtain a gallium oxide film; wherein, the pulse time of trimethyl gallium is 0.2 s, the carrier gas flow of trimethyl gallium is 200 sccm, the carrier gas of trimethyl gallium is N2, the pulse time of O2 plasma is 30 s, the power of O2 plasma is 500 W, and the purge time of N2 is 5 s;

[0066] (5) pulse bis-diethylaminosilane into the vacuum reaction chamber, after the pulse is over, use N2 to purge, then pulse O2 plasma, after the pulse is over, use N2 to purge, to deposit a layer of SiO2 film on the gallium oxide film; wherein, the pulse time of bis-diethylaminosilane is 0.2 s, the carrier gas flow of bis-diethylaminosilane is 200 sccm, the carrier gas of bis-diethylaminosilane is N2, the pulse time of O2 plasma is 30 s, the power of O2 plasma is 500 W, and the purge time of N2 is 5 s;

[0067] (6) pulse trimethyl gallium into the vacuum reaction cavity, after the pulse end, use N2 to blow, then pulse O2 plasma, after the pulse end, use N2 to blow, repeat the above process 6 times, namely, deposit gallium oxide film on the SiO2 film; wherein, the pulse time of trimethyl gallium is 0.2s, the carrier gas flow of trimethyl gallium is 200sccm, the carrier gas of trimethyl gallium is N2, the pulse time of O2 plasma is 30s, the power of O2 plasma is 500W, the blowing time of N2 is 5s;

[0068] (7) repeat steps (4)-(6) for 50 times as a cycle to obtain a Si-doped gallium oxide film with a thickness of 40nm;

[0069] (8) anneal the Si-doped gallium oxide film in an oxygen atmosphere at a heating rate of 6℃ / min to 900℃ for 60min to obtain a wafer-level Si-doped β-Ga2O3 film.

[0070] Test the performance of the Si-doped β-Ga2O3 film prepared above, the visible light transmittance is greater than 90%, the band gap is between 4.5-5.3eV, XRD measurement shows that the film presents (-201) preferred orientation, and the FWHM is less than 500 arcsec.

[0071] Example 2

[0072] (1) take (0001) oriented sapphire as a substrate, clean the (0001) oriented sapphire substrate, the specific process is: first, wash the (0001) oriented sapphire substrate with deionized water, then put it into an acetone solution, oscillate and clean the (0001) oriented sapphire substrate in an ultrasonic oscillator for 30min, then put the (0001) oriented sapphire substrate into deionized water, oscillate and clean the (0001) oriented sapphire substrate in an ultrasonic oscillator for 15min, finally, ultrasonic clean with 0.5% hydrofluoric acid solution for 30s, then wash with deionized water for 3min, and finally dry with high-purity nitrogen;

[0073] (2) put the cleaned (0001) oriented sapphire substrate into the vacuum reaction cavity of the atomic layer deposition equipment, heat to the preset temperature of 280℃, then functionalize the substrate with O2 plasma for 600s, the power of O2 plasma is 500W;

[0074] (3) take trimethyl gallium as gallium source, O2 plasma as oxygen source, bisdiethylaminosilane as silicon source, and N2 as blowing gas;

[0075] (4) pulse trimethyl gallium into the vacuum reaction cavity, after the pulse end, using N2purge, then pulse O2plasma, after the pulse end, using N2purge, repeat the above process 3 times, get gallium oxide film; wherein, the pulse time of trimethyl gallium is 0.2s, the carrier gas flow of trimethyl gallium is 200sccm, the carrier gas of trimethyl gallium is N2, the pulse time of O2plasma is 30s, the power of O2plasma is 500W, the purge time of N2is 5s;

[0076] (5) pulse bisdiethylaminosilane into the vacuum reaction cavity, after the pulse end, using N2purge, then pulse O2plasma, after the pulse end, using N2purge, can deposit a layer of SiO2film on the gallium oxide film; wherein, the pulse time of bisdiethylaminosilane is 0.2s, the carrier gas flow of bisdiethylaminosilane is 200sccm, the carrier gas of bisdiethylaminosilane is N2, the pulse time of O2plasma is 30s, the power of O2plasma is 500W, the purge time of N2is 5s;

[0077] (6) pulse trimethyl gallium into the vacuum reaction cavity, after the pulse end, using N2purge, then pulse O2plasma, after the pulse end, using N2purge, repeat the above process 4 times, deposit gallium oxide film on the SiO2film; wherein, the pulse time of trimethyl gallium is 0.2s, the carrier gas flow of trimethyl gallium is 200sccm, the carrier gas of trimethyl gallium is N2, the pulse time of O2plasma is 30s, the power of O2plasma is 500W, the purge time of N2is 5s;

[0078] (7) repeat step (4) to (6) for 30 times as a cycle, get Si doped gallium oxide film with thickness of 16nm;

[0079] (8) anneal the Si doped gallium oxide film in oxygen atmosphere, with heating rate of 6℃ / min to 900℃ for 60min, get wafer level Si doped β-Ga2O3film.

[0080] Example 3

[0081] (1) using (0001) oriented sapphire as a substrate, cleaning the (0001) oriented sapphire substrate, the specific process is: first, using deionized water to flush the (0001) oriented sapphire substrate, then put it into the acetone solution, oscillate and clean the (0001) oriented sapphire substrate in the ultrasonic oscillator for 30 min, then put the (0001) oriented sapphire substrate into the deionized water, oscillate and clean the (0001) oriented sapphire substrate in the ultrasonic oscillator for 15 min, finally, ultrasonic cleaning with 0.5% hydrofluoric acid solution for 30 s, then flush with deionized water for 3 min, and dry with high-purity nitrogen;

[0082] (2) put the cleaned (0001) oriented sapphire substrate into the vacuum reaction chamber of the atomic layer deposition equipment, heat to the preset temperature 400℃, then use NH3 plasma to functionalize the substrate for 300 s, the power of NH3 plasma is 800 W;

[0083] (3) using trimethylaluminum as aluminum source, NH3 plasma as nitrogen source, titanium tetrachloride as titanium source, N2 as purge gas; heat the tank containing metal-organic precursors, control the temperature of trimethylaluminum at 18℃, and control the temperature of titanium tetrachloride at 20℃;

[0084] (4) pulse trimethylaluminum into the vacuum reaction chamber, after the pulse is over, use N2 to purge, then pulse NH3 plasma, after the pulse is over, use N2 to purge, repeat the above process 3 times to obtain an aluminum nitride film; wherein, the pulse time of trimethylaluminum is 0.2 s, the carrier gas flow of trimethylaluminum is 150 sccm, the carrier gas of trimethylaluminum is N2, the pulse time of NH3 plasma is 10 s, the power of NH3 plasma is 800 W, and the purge time of N2 is 10 s;

[0085] (5) pulse titanium tetrachloride into the vacuum reaction chamber, after the pulse is over, use N2 to purge, then pulse NH3 plasma, after the pulse is over, use N2 to purge, to deposit a layer of titanium nitride on the aluminum nitride film; wherein, the pulse time of titanium tetrachloride is 0.2 s, the carrier gas flow of titanium tetrachloride is 150 sccm, the carrier gas of titanium tetrachloride is N2, the pulse time of NH3 plasma is 10 s, the power of NH3 plasma is 800 W, and the purge time of N2 is 10 s;

[0086] (6) pulse trimethylaluminum into the vacuum reaction cavity, after the pulse is over, use N2 to perform purging, then pulse NH3 plasma, after the pulse is over, use N2 to perform purging, repeat the above process 4 times, that is, deposit aluminum nitride film on the titanium nitride film layer; wherein, the pulse time of trimethylaluminum is 0.2s, the carrier gas flow of trimethylaluminum is 150sccm, the carrier gas of trimethylaluminum is N2, the pulse time of NH3 plasma is 10s, the power of NH3 plasma is 800W, the purging time of N2 is 10s;

[0087] (7) repeat steps (4)-(6) as a cycle for 80 times, to obtain Ti-doped aluminum nitride film with a thickness of 58nm;

[0088] (8) anneal the Ti-doped aluminum nitride film at 500℃ for 60min under nitrogen atmosphere, to obtain wafer-level Ti-doped aluminum nitride film.

[0089] Example 4

[0090] (1) take (0001) oriented sapphire as a substrate, clean the (0001) oriented sapphire substrate, the specific process is: first, wash the (0001) oriented sapphire substrate with deionized water, then put it into an acetone solution, oscillate and clean the (0001) oriented sapphire substrate in an ultrasonic oscillator for 30min, then put the (0001) oriented sapphire substrate into deionized water, oscillate and clean the (0001) oriented sapphire substrate in an ultrasonic oscillator for 15min, finally, ultrasonic clean with 0.5% hydrofluoric acid solution for 30s, then wash with deionized water for 3min, and dry with high-purity nitrogen;

[0091] (2) put the cleaned (0001) oriented sapphire substrate into the vacuum reaction cavity of the atomic layer deposition equipment, heat to a preset temperature of 280℃, then use O2 plasma to functionalize the substrate for 200s, the power of O2 plasma is 600W;

[0092] (3) take trimethylgallium as gallium source, O2 plasma as oxygen source, and N2 as purging gas;

[0093] (4) pulse trimethylgallium into the vacuum reaction cavity, after the pulse is over, use N2 to perform purging, then pulse O2 plasma, after the pulse is over, use N2 to perform purging, repeat the above process 50 times, to obtain 36nm thick gallium oxide film; wherein, the pulse time of trimethylgallium is 0.2s, the carrier gas flow of trimethylgallium is 250sccm, the carrier gas of trimethylgallium is N2, the pulse time of O2 plasma is 30s, the power of O2 plasma is 600W, the purging time of N2 is 5s;

[0094] (5) The gallium oxide film is annealed at 900℃ for 60min at a temperature increasing rate of 6℃ / min in an oxygen atmosphere to obtain a wafer-level α-Ga2O3 film.

[0095] The α-Ga2O3 film prepared above is tested for performance, and the visible light transmittance is greater than 90%, the band gap is between 4.5-5.3eV, XRD measurement shows that the α-Ga2O3 film is (006) epitaxial orientation, and the FWHM is less than 400 arcsec.

[0096] Example 5

[0097] (1) A (0001)-oriented sapphire substrate is cleaned, and the specific process is as follows: first, the (0001)-oriented sapphire substrate is rinsed with deionized water, then placed in an acetone solution, and oscillated and cleaned in an ultrasonic oscillator for 30min, then placed in deionized water, oscillated and cleaned in an ultrasonic oscillator for 15min, and finally ultrasonically cleaned with 0.5% hydrofluoric acid solution for 30s, then rinsed with deionized water for 3min, and dried with high-purity nitrogen;

[0098] (2) The cleaned (0001)-oriented sapphire substrate is placed in the vacuum reaction chamber of an atomic layer deposition device, the pressure of the vacuum reaction chamber is 800Pa, and the substrate is heated to a preset temperature of 280℃, then the substrate is functionalized by O2 plasma for 200s, and the power of the O2 plasma is 500W;

[0099] (3) Trimethyl gallium is used as the gallium source, tetra(dimethylamine) tin is used as the tin source, O2 plasma is used as the oxygen source, and N2 is used as the purge gas;

[0100] (4) Trimethyl gallium is pulsed into the vacuum reaction chamber, then purged with N2 after the pulse is completed, then pulsed with O2 plasma, then purged with N2 after the pulse is completed, and the above process is repeated 5 times; wherein the pulse time of trimethyl gallium is 0.2s, the carrier gas flow rate of trimethyl gallium is 200sccm, the carrier gas of trimethyl gallium is N2, the pulse time of O2 plasma is 30s, the power of O2 plasma is 500W, and the purge time of N2 is 5s;

[0101] (5) pulse tetra (dimethylamine) tin into the vacuum reaction cavity, after the pulse end using N2purge, then pulse O2plasma, after the pulse end using N2purge; wherein, the pulse time of tetra (dimethylamine) tin is 0.2s, the carrier gas flow of tetra (dimethylamine) tin is 200sccm, the carrier gas of tetra (dimethylamine) tin is N2, the pulse time of O2plasma is 30s, the power of O2plasma is 500W, the purge time of N2is 5s;

[0102] (6) pulse trimethyl gallium into the vacuum reaction cavity, after the pulse end using N2purge, then pulse O2plasma, after the pulse end using N2purge, repeat the above process 6 times; wherein, the pulse time of trimethyl gallium is 0.2s, the carrier gas flow of trimethyl gallium is 200sccm, the carrier gas of trimethyl gallium is N2, the pulse time of O2plasma is 30s, the power of O2plasma is 500W, the purge time of N2is 5s;

[0103] (7) repeat 50 times with steps (4)-(6) as a cycle, obtain Sn doped gallium oxide film with thickness of 41nm;

[0104] (6) anneal the Sn doped gallium oxide film in oxygen atmosphere, heat to 900℃ at a heating rate of 6℃ / min, and then anneal for 60min, obtain wafer level Sn doped α-Ga2O3film.

[0105] The above only describes the preferred embodiments of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A method for producing a wafer-level epitaxial film, characterized by, The method comprises the following steps: (1) placing a substrate into a vacuum reaction chamber of an atomic layer deposition device, heating to a preset temperature, and then performing functionalization treatment on the substrate by using an M source; (2) A source, M source are pulsed into the vacuum reaction cavity in turn, and A x M y A thin film layer is formed; then a precursor source of a doping atom and a M source are pulsed to form a doping atom layer; then an A source and a M source are pulsed in turn, and A x M y A thin film layer is formed; then a precursor source of a doping atom and a M source are pulsed to form a doping atom layer; then an A source and a M source are pulsed in turn, and A or sequentially pulsing the A source and the M source into the vacuum reaction chamber, and then repeating the pulsing of the A source and the M source to obtain A x M y thin film (3) annealing the doped thin film or A x M y annealing the thin film to obtain a wafer-level epitaxial nitride / oxide thin film; A in the step (2) x M y one of gallium oxide, gallium nitride, aluminum nitride, hafnium oxide In the step (2), the doping atom is silicon, nitrogen, sulfur, aluminum, copper, tin, titanium or tantalum; when the doping atom is silicon, the precursor source of the doping atom is tris(dimethylamino)silane or bis(diethylamino)silane; when the doping atom is nitrogen, the precursor source of the doping atom is NH3; when the doping atom is sulfur, the precursor source of the doping atom is H2S; when the doping atom is aluminum, the precursor source of the doping atom is trimethylaluminum, triethylaluminum or dimethylisopropoxyaluminum; when the doping atom is copper, the precursor source of the doping atom is bis(dimethylamine-2-propanol)copper; when the doping atom is titanium, the precursor source of the doping atom is titanium tetraisopropoxide, titanium tetraethoxide or tetrakis(dimethylamino)titanium; when the doping atom is tantalum, the precursor source of the doping atom is ethoxy tantalum, pentakis(dimethylamino)tantalum or tris(diethylamino)tantalum tert-butanamide; and when the doping atom is tin, the precursor source of the doping atom is tetrakis(dimethylamine)tin.

2. The method of claim 1, wherein the substrate is a wafer. In the step (1), the substrate is a silicon substrate or a sapphire substrate; the preset temperature is 150-500 ℃; the pressure in the vacuum reaction chamber is 500-1500 Pa; and the functionalization treatment time is 120-600 s.

3. The method of claim 1 or 2, wherein the substrate is a wafer. A source in the step (2) when A x M y is gallium oxide or gallium nitride, the A source is trimethyl gallium or triethyl gallium; A x M y is aluminum nitride, the A source is trimethyl aluminum or triethyl aluminum; A x M y is hafnium oxide, the A source is tetrakis(dimethylamine)hafnium or tris(dimethylamido) cyclopentadienyl hafnium.

4. The method of claim 3, wherein the substrate is a wafer. In the step (2), the M source is a nitrogen source or an oxygen source; the nitrogen source is N2 plasma, NH3 or NH3 plasma; and the oxygen source is O2 plasma or ozone.

5. The method of claim 4, wherein the substrate is a wafer. In the step (2), the pulse time of the A source is independently 0.1-0.4 s, the carrier gas flow of the A source is independently 100-300 sccm, and the carrier gas of the A source is independently N2 or Ar; the pulse time of the precursor source of the doping atom is 0.1-0.5 s, the carrier gas flow of the precursor source of the doping atom is 100-300 sccm, and the carrier gas of the precursor source of the doping atom is N2 or Ar; and the pulse time of the M source is independently 3-60 s.

6. The method of claim 5, wherein the substrate is a wafer. The step (2) doped thin film or A x M y The total thickness of the thin film is independently 5-1000 nm.

7. The method of claim 6, wherein the substrate is a wafer. In the step (3), the annealing treatment is performed at a temperature of 350-1100 ℃ for 30-120 min at a temperature rising rate of 5-10 ℃ / min.

8. A wafer-level epitaxial film prepared by the method of any one of claims 1-7.

Images