阅读说明：本技术 基于蓝宝石衬底的氧化镓薄膜及其生长方法和应用 (Gallium oxide film and its growing method and application based on Sapphire Substrate ) 是由 张晓东 范亚明 *** 于 2018-05-18 设计创作，主要内容包括：本发明公开了一种基于蓝宝石衬底的氧化镓薄膜及其生长方法和应用。所述的基于蓝宝石衬底的氧化镓薄膜的制备方法包括：以脉冲外延生长方式在蓝宝石衬底上形成一个以上α-(Al<Sub>x</Sub>Ga<Sub>1-x</Sub>)<Sub>2</Sub>O<Sub>3</Sub>应变缓冲层,其中0.99≥x≥0.01；以及,在所述α-(Al<Sub>x</Sub>Ga<Sub>1-x</Sub>)<Sub>2</Sub>O<Sub>3</Sub>应变缓冲层上形成氧化镓外延层。采用本发明实施例提供的生长方法,不仅可以避免α-Ga<Sub>2</Sub>O<Sub>3</Sub>和α-Al<Sub>2</Sub>O<Sub>3</Sub>外延温度相矛盾的技术难点,还可以有效降低α-Ga<Sub>2</Sub>O<Sub>3</Sub>外延薄膜的缺陷密度,进而提高α-Ga<Sub>2</Sub>O<Sub>3</Sub>外延薄膜材料的晶体质量。(The gallium oxide film and its growing method and application that the invention discloses a kind of based on Sapphire Substrate.The preparation method of the gallium oxide film based on Sapphire Substrate includes: to form more than one α-(Al on a sapphire substrate with pulse epitaxial growth regime x Ga 1‑x ) 2 O 3 Strained buffer layer, wherein 0.99 >=x >=0.01；And in the α-(Al x Ga 1‑x ) 2 O 3 Gallium oxide epitaxial layer is formed on strained buffer layer.It, not only can be to avoid α-Ga using growing method provided in an embodiment of the present invention 2 O 3 With α-Al 2 O 3 α-Ga can also be effectively reduced in the technological difficulties that epitaxial temperature contradicts 2 O 3 The defect concentration of epitaxial film, and then improve α-Ga 2 O 3 The crystal quality of epitaxial thin film material.)

1. a kind of preparation method of the gallium oxide film based on Sapphire Substrate, characterized by comprising:

More than one α-(Al is formed on a sapphire substrate with pulse epitaxial growth regime_xGa_1-x)₂O₃Strained buffer layer, wherein 0.99≥x≥0.01；And

In the α-(Al_xGa_1-x)₂O₃Gallium oxide epitaxial layer is formed on strained buffer layer.

2. preparation method according to claim 1, characterized by comprising: Sapphire Substrate is placed in reaction chamber, it Oxygen source, gallium source and/or silicon source are individually entered in different time by reaction chamber using pulse mode afterwards, with form described one with Upper α-(Al_xGa_1-x)₂O₃Strained buffer layer.

3. preparation method according to claim 1, it is characterised in that specifically include: in each growth cycle period, Any one of oxygen source, gallium source and/or silicon source are persistently first inputted into reaction chamber in first time period, then were spaced for one second time Section, persistently inputs reaction chamber for the other of oxygen source, gallium source and/or silicon source within the third period later, then is spaced one the Four periods.

4. preparation method according to claim 3, it is characterised in that: when the first time period, second time period, third Between section, the when a length of 0.1-99s of the 4th period.

5. preparation method according to claim 2 or 3, it is characterised in that: the oxygen source is selected from oxygen carrier；Preferably, The oxygen carrier include in oxygen gas and water, nitrous oxide, nitric oxide, carbon dioxide and carbon monoxide any one or Two or more combinations.

6. preparation method according to claim 2 or 3, it is characterised in that: the gallium source is selected from the organic compound containing gallium； Preferably, the gallium source includes trimethyl gallium and/or triethyl-gallium；And/or source of aluminium is selected from the organic compound containing aluminium； Preferably, source of aluminium includes trimethyl aluminium and/or triethyl-gallium.

7. preparation method according to claim 1 or 2, it is characterised in that: the α-(Al_xGa_1-x)₂O₃Strained buffer layer Growth pressure is 10~760Torr, and growth temperature is 100~1000 DEG C.

8. preparation method according to claim 1, characterized by comprising: sequentially form 1-99 on a sapphire substrate α-(the Al_xGa_1-x)₂O₃Strained buffer layer.

9. preparation method according to claim 1 or 8, it is characterised in that: a α-(Al_xGa_1-x)₂O₃Strain relief Layer with a thickness of 1-1000nm.

10. preparation method according to claim 1 or 8, it is characterised in that: wherein at least two α-(Al_xGa_1-x)₂O₃Layer The content of middle Al element is not identical.

11. preparation method according to claim 1, it is characterised in that: the growth pressure of the gallium oxide epitaxial layer is 10 ~760Torr, growth temperature are 100~600 DEG C.

12. according to claim 1 or preparation method described in 11, it is characterised in that: the material of the gallium oxide epitaxial layer is α- Ga₂O₃。

13. the gallium oxide film based on Sapphire Substrate prepared by preparation method of any of claims 1-12.

14. a kind of gallium oxide film based on Sapphire Substrate, including Sapphire Substrate and gallium oxide epitaxial layer, feature exist In: more than one α-(Al is also formed between the Sapphire Substrate and gallium oxide epitaxial layer_xGa_1-x)₂O₃Strained buffer layer, In 0.99 >=x >=0.01.

15. the gallium oxide film according to claim 14 based on Sapphire Substrate, it is characterised in that: every α- (Al_xGa_1-x)₂O₃Layer with a thickness of 1-1000nm；And/or the gallium oxide film includes 1-99 α-(Al_xGa_1-x)₂O₃Layer； And/or wherein at least two α-(Al_xGa_1-x)₂O₃The content of the Al element of layer is not identical.

16. the gallium oxide film based on Sapphire Substrate as described in claim 13,14 or 15 is in production semiconductor power device Purposes in part or semiconductor photoelectronic device.

Technical field

The present invention relates to a kind of growing method of semiconductor material, in particular to a kind of gallium oxide based on Sapphire Substrate Film and its growing method, belong to semiconductor technology and electronic technology field.

Background technique

Semiconductor material plays irreplaceable role in present information industrialization society, is modern semiconductors industry And the foundation stone of microelectronics industry.With the continuous development of various advanced technologies, to high voltage, high-power, anti-radiation contour performance Electronic device and deep ultraviolet light electronic device demand are more more and more urgent, traditional especially in high voltage and deep ultraviolet field Semiconductor material has been difficult to meet requirement.

Ultra-wide band gap oxide semiconductor-gallium oxide (Ga₂O₃), compared to third generation semiconductor material, such as gallium nitride (GaN) and silicon carbide (SiC), have that bigger forbidden bandwidth, higher disruptive field intensity, electrically conducting transparent, can to pass through melt method raw Long, the more low advantage of cost, and become the research hotspot in the fields such as semiconductor material and device.

Ga₂O₃Material shares α, beta, gamma, crystal phase known to five kinds of δ, ε, wherein β-Ga₂O₃(Eg=4.7~4.9eV) structure It is the most stable and can and other four kinds of gallium oxides between mutual inversion of phases.However α-Ga₂O₃Forbidden bandwidth reaches 5.3eV, can effectively mention High device pressure resistance performance, α-Ga₂O₃The mobility of material is also above β-Ga₂O₃, therefore device performance is better than β-Ga₂O₃.And α- Ga₂O₃Have many advantages, such as that excellent chemical stability, thermal stability and breakdown field are powerful, in deep-ultraviolet transparent conductive film, ultraviolet The fields such as detector, semiconductor power device, spin electric device, gas sensor have broad application prospects.

Currently, α-Ga₂O₃The common preparation method of material has various chemical vapor depositions (chemical vapor Deposition, CVD) such as MOCVD, LPCVD, Mist-CVD, molecular beam epitaxy (molecular beam epitaxy, MBE), halide gas phase extension (HVPE), atomic layer deposition (ALD) etc..

α-Ga₂O₃Belong to trigonal system,Space group, (lattice constant isα=β= 90 °, γ=120 °, thermalexpansioncoefficientα=5.23 × 10^-6/℃).C surface sapphire (α-Al₂O₃, α=β=90 °, γ=120 °, α=5.22 × 10^-6/ DEG C) and α-Ga₂O₃Crystal structure is identical, is all corundum structure, is suitble to do α-Ga₂O₃Hetero-epitaxy substrate.At present studies have reported that can be blue precious using mist chemical vapour deposition technique (Mist-CVD) α-the Ga of high quality is grown on stone (Sapphire) substrate₂O₃, and Schottky diode (SBD) performance prepared is better than SiCSBD. It therefore, can low cost, large scale preparation α-Ga by using cheap Sapphire substrate and CVD growth technology₂O₃Material With device.

Although α-Ga₂O₃With α-Al₂O₃Crystal structure is identical, but the difference of differences between lattice constant and thermal conductivity causes extension When there are a degree of mismatches, so as to cause α-Ga₂O₃Dislocation increases, and film peeling, this has just seriously affected the application of material With the development of device.

Summary of the invention

The gallium oxide film and its growing method that the main purpose of the present invention is to provide a kind of based on Sapphire Substrate and Using with overcome the deficiencies in the prior art.

For realization aforementioned invention purpose, the technical solution adopted by the present invention includes:

The preparation method of the embodiment of the invention provides a kind of gallium oxide film based on Sapphire Substrate comprising:

More than one α-(Al is formed on a sapphire substrate with pulse epitaxial growth regime_xGa_1-x)₂O₃Strained buffer layer, Wherein 0.99 >=x >=0.01；And

In the α-(Al_xGa_1-x)₂O₃Gallium oxide epitaxial layer is formed on strained buffer layer.

The embodiment of the invention also provides the gallium oxide films based on Sapphire Substrate by the preparation method preparation.

The embodiment of the present invention also provides a kind of gallium oxide film based on Sapphire Substrate, including Sapphire Substrate and oxidation Gallium epitaxial layer is also formed with more than one α-(Al between the Sapphire Substrate and gallium oxide epitaxial layer_xGa_1-x)₂O₃It should slow down Layer is rushed, wherein 0.99 >=x >=0.01.

The embodiment of the invention also provides the described gallium oxide film based on Sapphire Substrate is in production semiconductor power The purposes of device and semiconductor photoelectronic device field.

Compared with prior art, growing method based on the embodiment of the present invention forms α-(Al_xGa_1-x)₂O₃It should slow down Layer is rushed, it not only can be to avoid α-Ga₂O₃With α-Al₂O₃α-can also be effectively reduced in the technological difficulties that temperature contradicts in extension Ga₂O₃The defect concentration of epitaxial film, and then improve α-Ga₂O₃The crystal quality of epitaxial thin film material.

Detailed description of the invention

Fig. 1 is a kind of structural representation of the gallium oxide film based on Sapphire Substrate in an exemplary embodiments of the invention Figure；

Fig. 2 is oxygen source and aluminium/gallium source flow schematic diagram in pulsed epitaxial growth in an of the invention exemplary embodiments；

Fig. 3 is α-(Al in an exemplary embodiments of the invention_xGa_1-x)₂O₃The epitaxial growth schematic diagram of strained buffer layer.

Specific embodiment

In view of deficiency in the prior art, inventor is once attempted using pulsed epitaxy method low-temperature epitaxy difference Al α-(the Al of component_xGa_1-x)₂O₃Strained buffer layer structure, to alleviate α-Ga₂O₃Membrane stress reduces epitaxial film dislocation density, Improve α-Ga₂O₃Crystal quality.However, on the one hand, Al₂O₃Compared to Ga₂O₃There are smaller bond distance and higher decomposition temperature, because This extension α-Al₂O₃It is also required to higher temperature.Al atom the physics and chemical adsorption capacity of epi-layer surface, transfer ability, Ability and the desorption temperature etc. for being incorporated to lattice affect α-(Al_xGa_1-x)₂O₃Crystal quality.On the other hand, α-Ga₂O₃Outside Prolong and need low temperature, can be undergone phase transition when being higher than 550 DEG C, this results in the α-for growing high Al contents at a temperature of lower than this (Al_xGa_1-x)₂O₃Strained buffer layer has difficulties.Also that is, according to the aforementioned schemes that inventor once attempted, then not It can avoid α-Ga₂O₃With α-Al₂O₃The problem of epitaxial temperature contradicts.

For this purpose, inventor has carried out studying for a long period of time and largely practice again, just it is able to propose technical solution of the present invention, It is mainly by using pulsed epitaxy low-temperature epitaxy α-(Al_xGa_1-x)₂O₃Composite strain buffer structure solves the prior art The problem of.

The preparation method of the embodiment of the invention provides a kind of gallium oxide film based on Sapphire Substrate comprising:

More than one α-(Al is formed on a sapphire substrate with pulse epitaxial growth regime_xGa_1-x)₂O₃Strained buffer layer, Wherein 0.99 >=x >=0.01；And

In the α-(Al_xGa_1-x)₂O₃Gallium oxide epitaxial layer is formed on strained buffer layer.

Further, the preparation method includes: that Sapphire Substrate is placed in reaction chamber, uses pulse mode later Oxygen source, gallium source and/or silicon source are individually entered into reaction chamber in different time, to form more than one described α-(Al_xGa_1-x)₂O₃Strained buffer layer.

Further, the preparation method specifically includes: in each growth cycle period, first at the first time Any one of oxygen source, gallium source and/or silicon source persistently inputted into reaction chamber in section, then is spaced a second time period, later the The other of oxygen source, gallium source and/or silicon source are persistently inputted into reaction chamber in three periods, then were spaced for one the 4th period.

Further, the first time period, second time period, the when a length of 0.1- of third period, the 4th period 99s。

Further, the oxygen source is selected from the oxygen carrier for being capable of providing oxygen element.

Preferably, the oxygen carrier includes oxygen gas and water, nitrous oxide, nitric oxide, carbon dioxide and carbon monoxide In any one or two or more combinations, but not limited to this.

Further, the gallium source is selected from the organic compound containing gallium.

Preferably, the gallium source includes trimethyl gallium and/or triethyl-gallium, but not limited to this.

Further, source of aluminium is selected from the organic compound containing aluminium.

Preferably, source of aluminium includes trimethyl aluminium and/or triethyl-gallium, but not limited to this.

Further, the α-(Al_xGa_1-x)₂O₃The growth pressure of strained buffer layer is 10~760Torr, growth temperature It is 100~1000 DEG C.

Further, the preparation method includes: to sequentially form the 1-99 α-on a sapphire substrate (Al_xGa_1-x)₂O₃Strained buffer layer.

Further, a α-(Al_xGa_1-x)₂O₃Strained buffer layer with a thickness of 1-1000nm.

Further, wherein at least two α-(Al_xGa_1-x)₂O₃The content of Al element is not identical in layer.

Further, the growth pressure of the gallium oxide epitaxial layer is 10~760Torr, and growth temperature is 100~600 ℃。

Further, the material of the gallium oxide epitaxial layer is α-Ga₂O₃。

The embodiment of the invention also provides the gallium oxide films based on Sapphire Substrate by the preparation method preparation.

The embodiment of the present invention also provides a kind of gallium oxide film based on Sapphire Substrate, including Sapphire Substrate and oxidation Gallium epitaxial layer is also formed with more than one α-(Al between the Sapphire Substrate and gallium oxide epitaxial layer_xGa_1-x)₂O₃It should slow down Layer is rushed, wherein 0.99 >=x >=0.01.

Further, an every α-(Al_xGa_1-x)₂O₃Layer with a thickness of 1-1000nm.

Further, the gallium oxide film includes 1-99 α-(Al_xGa_1-x)₂O₃Layer.

Further, wherein at least two α-(Al_xGa_1-x)₂O₃The content of the Al element of layer is not identical.

The present invention by using pulsed epitaxy method low-temperature epitaxy difference Al component α-(Al_xGa_1-x)₂O₃Strain relief Layer structure, not only can be to avoid α-Ga₂O₃With α-Al₂O₃α-Ga can also be effectively reduced in the problem that temperature contradicts in extension₂O₃ The defect concentration of epitaxial film alleviates α-Ga₂O₃Membrane stress, and then improve α-Ga₂O₃The crystal quality of epitaxial thin film material.

The embodiment of the invention also provides the described gallium oxide film based on Sapphire Substrate is in production semiconductor power Purposes in device or semiconductor photoelectronic device.

As follows by conjunction with the embodiments and attached drawing to the technical solution, its implementation process and principle etc. of the embodiment of the present invention make into The explanation of one step.

Referring to Fig. 1, Fig. 1 shows a kind of gallium oxide film based on Sapphire Substrate in an exemplary embodiments of the invention Structural schematic diagram comprising Sapphire Substrate, and the multiple α-(Al being successively arranged on a sapphire substrate_xGa_1-x)₂O₃It answers Become buffer layer and one or more α-Ga₂O₃Epitaxial layer.

Gallium oxide film in the present embodiment based on Sapphire Substrate may include steps of:

1) pulsed epitaxy low-temperature epitaxy α-(Al is used on a sapphire substrate_xGa_1-x)₂O₃Strained buffer layer.This is outer The method for prolonging growth can be selected from chemical vapor deposition (chemical vapor deposition, CVD), especially MOCVD (Metallo-Organic Chemical Vapor deposition) etc., applicable equipment include CVD (chemical vapor depsotition equipment), LPCVD (low pressure chemical gas Phase depositing device), MOCVD (equipment of metal organic chemical vapor deposition), MBE (molecular beam epitaxial device), LMBE (laser molecular Beam epitaxy equipment), ALD (Atomic layer deposition equipment), PEALD (plasma enhanced atomic layer deposition equipment), HVPE (hydrogenation Object vapour phase epitaxy equipment) etc..

Specifically, please refer to Fig. 2 and Fig. 3, oxygen source (can be oxygen) and gallium/silicon source (such as triethyl-gallium/trimethyl Gallium) in a manner of pulse separation, periodically progress epitaxial growth, i.e., (the t in a pulse cycle₁、t₂、t₃、t₄Arteries and veins Rushing width point is to represent oxygen source and be passed through the time, intermittent time, gallium/silicon source of reaction chamber to be passed through the time of reaction chamber, intermittent time Four variables, they are alternated, wherein 0.1s≤t₁/t₂/t₃/t₄≤ 99s) it is (right by pulse cycle number, pulse width Oxygen source is answered, gallium/silicon source enters the time of reaction chamber) and pulse number (corresponding oxygen source, gallium/silicon source enter the number of reaction chamber) Flexible modulation and design, and then realize compared with high quality α-(Al under low temperature_xGa_1-x)₂O₃Thin-film material (the i.e. described strained buffer layer) Growth (making atomic migration to optimum position bonding at a lower temperature, to carry out high-quality thin film extension).

Oxygen source and gallium/silicon source are individually passed through by reaction chamber using pulsed extension in different times, can reduce O and Al/Ga contacts and occurs the chance of pre-reaction before reaching substrate, reduce fault in material caused by pre-reaction product deposits, increase Al/Ga atom makes Al/Ga-O in the best lattice point reaction bonding of aufwuchsplate, makes (Al in the lateral transfer rate of growing surface_xGa_1-x)₂O₃In conjunction with more regular, obtained when atom is integrated in crystal in a regular array, obtain atomically flat surface.

Growth course is controlled by adjusting pulsewidth, interval, period and the technological parameter of superposition time isopulse formula growth, It improves crystalline quality and passes through (Al on the basis of the buffer layer of different Al components_xGa_1-x)₂O₃(0.99 >=x >=0.01) temperature and The control of thickness adjusts the strain in epitaxial process, discharges stress.

Oxygen source in the embodiment can be selected from the various oxygen carriers that can generate O molecule, such as oxygen, water, an oxidation two Nitrogen, nitric oxide, carbon dioxide, carbon monoxide etc..

Gallium source in the embodiment can be selected from the metal organic source of various Ga, such as trimethyl gallium TEG, triethyl-gallium TMG； Other substances containing Ga.

Silicon source in the embodiment can be selected from the metal organic source of various Al, such as trimethyl aluminium TEA, triethyl-gallium TMA； Other substances containing Al.

Each α-(Al in the embodiment_xGa_1-x)₂O₃Pressure when strain relief layer epitaxially grown be preferably controlled to 10Torr~ 760Torr or higher pressure.

Each α-(Al in the embodiment_xGa_1-x)₂O₃The epitaxial growth temperature of strained buffer layer is preferably 100 DEG C~1000 DEG C.

Each α-(Al in the embodiment_xGa_1-x)₂O₃The epitaxial growth temperature of strained buffer layer is preferably 100 DEG C~600 DEG C.

Each α-(Al in the embodiment_xGa_1-x)₂O₃The value range of x is preferably 0.99 >=x >=0.01 in strained buffer layer.

α-(Al in the embodiment_xGa_1-x)₂O₃The number of plies of strained buffer layer is preferably 99 >=number of plies >=1.

Each α-(Al in the embodiment_xGa_1-x)₂O₃The thickness of strained buffer layer is preferably 1nm >=thickness >=1000nm.

Be delayed outside aforementioned pulse formula each time (t in the embodiment₁、t₂、t₃、t₄) it is preferably 99s >=t >=0.1s.

2) α-Ga is carried out₂O₃The growth of epitaxial layer

α-Ga in the embodiment₂O₃The growth apparatus of epitaxial layer can also be MOCVD (Metallo-Organic Chemical Vapor deposition) Deng it includes CVD (chemical vapor depsotition equipment) that applicable equipment, which includes applicable equipment, LPCVD (low-pressure chemical vapor deposition Equipment), MOCVD (equipment of metal organic chemical vapor deposition), MBE (LMBE) (molecular beam epitaxial device), ALD (PEALD) are (single Atomic layer deposition apparatus), HVPE (hydride gas-phase epitaxy equipment) etc..

Epitaxial growth pressure used by the step 2) of the embodiment is preferably 10Torr~760Torr or higher pressure

α-Ga in the embodiment₂O₃The growth temperature of epitaxial layer is preferably 100 DEG C~600 DEG C.

It, not only can be to avoid α-Ga using method provided in an embodiment of the present invention₂O₃With α-Al₂O₃Temperature phase lance in extension α-Ga can also be effectively reduced in the technological difficulties of shield₂O₃The defect concentration of epitaxial film, obtaining has ideal quality α-Ga₂O₃Epitaxial thin film material.

It should be appreciated that the technical concepts and features of above-described embodiment only to illustrate the invention, its object is to allow be familiar with this The personage of item technology cans understand the content of the present invention and implement it accordingly, and it is not intended to limit the scope of the present invention.It is all Equivalent change or modification made by Spirit Essence according to the present invention, should be covered by the protection scope of the present invention.