CN102903618B - Based on the direct epitaxial growth method of Graphene CVD of AlN substrate and the device of manufacture - Google Patents

Abstract

The invention discloses a kind of direct epitaxial growth method of Graphene CVD based on AlN substrate, adopt Group III-V compound semiconductor AlN as substrate, by carrying out rational preliminary treatment to AlN substrate, growth regulation pressure, flow and temperature, direct growth Graphene on AlN, without the need to metal as catalyst, the Graphene of growth is without the need to transfer process, just can be directly used in and manufacture various device, improve the electrology characteristic of device, reliability, reduce the complexity that device manufactures.Can grow the large-area graphene material with semiconductor cleanliness factor, the controllability of individual layer is more than 80%, and disk area is maximum can to 8 inches.

Description

Based on the direct epitaxial growth method of Graphene CVD of AlN substrate and the device of manufacture

Technical field

The invention belongs to semi-conducting material and manufacture field, relate to key technology prepared by semi-conducting material, particularly based on the controlled epitaxial growth method of large-area graphene of Group III-V compound semiconductor AlN substrate, can be used for the preparation of the large area wafer level grapheme material without the need to transfer.

Technical background

Along with the development of integrated circuit, the critical size of current silicon (Si) base device has reached the theory and technology limit, and quantum effect has become main restriction scheme.Grapheme material is a kind of carbon back two dimensional crystal, and be known the thinnest the lightest material at present, individual layer only atomic thickness, it has extremely excellent physicochemical properties, and (theory is estimated to exceed 200000cm to such as high carrier mobility ²v ^-1s ^-1it is hundreds of times of Si), superpower mechanical performance (Young's modulus is about 1000GP), high specific area and fabulous gas-sensitive property, the high transparency and pliability, and there is not mismatch problems in it and substrate, can be completely compatible with Si base device technique, there is outstanding industrial advantage.Therefore, Graphene appear as industrial circle and scientific and technological circle bring dawn, it is the new material that the alternative Si be expected most becomes base semiconductor material of future generation.

Although Graphene has so excellent character, in the preparation of Graphene, still there is key issue much urgently to be resolved hurrily at present.The wafer level graphene growing method of main flow is based on transition metal-catalyzed CVD in the world at present, can be used for the preparation of large-area graphene, and not by the restriction of substrate dimension, equipment is simple.A shortcoming the most significant to use metal catalytic substrate, therefore be difficult to Graphene to clean and transfer to other and be applicable in the dielectric substrate of device, and the residue remained in after transfer process on Graphene or pollutant will reduce the mobility of Graphene, thus affect the electrology characteristic of graphene device.Therefore, the restriction of prior art must be broken through, courageously break through technique, explore new substrate, realize the clean graphene growth method of large area without transfer.

Aluminium nitride (AlN) is a kind of broad stopband (6.2eV) semi-conducting material, has direct band gap, can be used for the manufacture of deep UV (ultraviolet light) electric device, and the emission wavelength of AlN based light-emitting diode can reach 210nm.Along with AlN thin film heterogeneity epitaxial growth technology is increasingly mature, AlN base ultra-wide forbidden band heterostructure HEMT device obtains to be paid close attention to widely, can be used for HTHP device.Extension AlN film also has good piezoelectric property, can be used for preparing surface acoustic wave sensors.In addition, AlN can also be used for the dielectric layer of photoelectric storage, the substrate of electronic device, the chip carrier of high thermal conductance, for the radio-frequency filter etc. of mobile communication.In a word, AlN is the very potential semi-conducting material of one.

Graphene is six side's honeycombs, and lattice constant is 0.246nm, and buergerite AlN is also hexagonal structure, and lattice constant is 0.3112nm, and the lattice mismatch of the two is less, effectively reduces the strain in Graphene.The Surface Polarization optical phonon energy of AlN film is 83.60meV, 104.96meV, and energy is higher, and at room temperature phonon is more weak to the scattering process of charge carrier in graphene film, and the Graphene as seen based on AlN substrate has very high electrology characteristic.In order to be combined with Graphene by Al N, and without Graphene transfer process, to obtain high-quality large-area graphene material, be necessary that research directly carries out Graphene CVD epitaxial growth on AlN substrate.

Summary of the invention

The object of the invention is to overcome the deficiency in existing large-area graphene growing technology, propose a kind of large-area high-quality graphene growth method without the need to transfer based on AlN substrate, to improve the electrology characteristic of Graphene and device.

Realizing key problem in technology of the present invention is: adopt Group III-V compound semiconductor AlN as substrate, by carrying out rational preliminary treatment to AlN substrate, growth regulation pressure, flow and temperature, direct growth Graphene on AlN, without the need to metal as catalyst, the Graphene of growth, without the need to transfer process, just can be directly used in and manufacture various device, improve the electrology characteristic of device, reliability, reduces the complexity that device manufactures.Its growing method performing step comprises as follows:

(1) AlN substrate is successively put into acetone, clean in ethanol and deionized water, each time 10-30min, takes out substrate from deionized water, dries up with high pure nitrogen (99.9999%).

(2) AlN substrate is put into chemical vapor deposition CVD reative cell, extracting vacuum to 10 ^-5-10 ^-6torr, to remove the residual gas in reative cell;

(3) in reative cell, H is passed into ₂carry out substrate surface preliminary treatment, gas flow 1-20sccm, reative cell vacuum degree 0.1-1Torr, underlayer temperature 900-1000 DEG C, processing time 5-10min;

(4) in reative cell, Ar and CH is passed into ₄, keep Ar and CH ₄flow-rate ratio be 10: 1-2: 1, Ar flow 20-200sccm, CH ₄flow 1-20sccm, air pressure maintains 0.2-1atm, temperature 1000-1100 DEG C, heating-up time 20-60min, retention time 50-100min;

(5) Temperature fall is to less than 100 DEG C, keeps Ar and CH in operation (3) ₄flow is constant, air pressure 0.2-1atm, completes the growth of Graphene.

Through above operation, can grow the large-area graphene material with semiconductor cleanliness factor, the controllability of individual layer is more than 80%, and disk area is maximum can to 8 inches.

Tool of the present invention has the following advantages:

1., owing to adopting AlN as substrate, the Graphene of growth just may be used for the manufacture of device without the need to transfer, improve reliability and the electrology characteristic of device.

2., owing to adopting AlN as substrate, simplify graphene growth step and device fabrication step, reduce Graphene manufacturing cost.

Accompanying drawing explanation

Fig. 1 is the graphene growth flow chart based on AlN substrate of the present invention;

Fig. 2 is the graphene growth procedure structure schematic diagram based on AlN substrate of the present invention.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.

With reference to Fig. 1, the present invention provides following embodiment:

Embodiment 1:

Performing step of the present invention is as follows:

Step 1, AlN substrate prepares.

AlN substrate is successively put into acetone, and clean in ethanol and deionized water, each time 10min, takes out substrate from deionized water, dries up with high pure nitrogen (99.9999%).

Step 2, reative cell vacuumizes.

The AlN substrate of semiconductor device levels is placed in chemical vapor deposition CVD reative cell, extracting vacuum to 10 ^-6torr, to remove the residual gas in reative cell.

Step 3, the preliminary treatment of AlN substrate surface.

H is passed in reative cell ₂carry out substrate surface preliminary treatment, gas flow 2sccm, reative cell vacuum degree 0.1Torr, underlayer temperature 950 DEG C, processing time 5min.

Step 4, Graphene CVD epitaxial growth.

Ar and CH is passed in reative cell ₄, keep Ar and CH ₄flow-rate ratio be 10: 1, Ar flow 20sccm, CH ₄flow 2sccm, air pressure maintains 0.5atm, temperature 1100 DEG C, heating-up time 20min, retention time 80min.

Step 5, cooling procedure.

Temperature fall, to less than 100 DEG C, keeps Ar and CH in operation (3) ₄flow is constant, air pressure 0.5atm, completes the growth of Graphene.

Embodiment 2:

Performing step of the present invention is as follows:

Steps A, A1N substrate prepares.

AlN substrate is successively put into acetone, and clean in ethanol and deionized water, each time 20min, takes out substrate from deionized water, dries up with high pure nitrogen (99.9999%).

Step B, reative cell vacuumizes.

The AlN substrate of semiconductor device levels is placed in chemical vapor deposition CVD reative cell, extracting vacuum to 10 ^-6torr, to remove the residual gas in reative cell.

The preliminary treatment of step C, AlN substrate surface.

H is passed in reative cell ₂carry out substrate surface preliminary treatment, gas flow 5sccm, reative cell vacuum degree 0.2Torr, underlayer temperature 950 DEG C, processing time 10min.

Step D, Graphene CVD epitaxial growth.

Ar and CH is passed in reative cell ₄, keep Ar and CH ₄flow-rate ratio be 8: 1, Ar flow 40sccm, CH ₄flow 5sccm, air pressure maintains 0.2atm, temperature 1050 DEG C, heating-up time 20min, retention time 80min.

Step e, cooling procedure.

Temperature fall, to less than 100 DEG C, keeps Ar and CH in operation (3) ₄flow is constant, air pressure 0.2atm, completes the growth of Graphene.

Embodiment 3:

Performing step of the present invention is as follows:

Step one, AlN substrate prepares.

AlN substrate is successively put into acetone, and clean in ethanol and deionized water, each time 30min, takes out substrate from deionized water, dries up with high pure nitrogen (99.9999%).

Step 2, reative cell vacuumizes.

The AlN substrate of semiconductor device levels is placed in chemical vapor deposition CVD reative cell, extracting vacuum to 10 ^-6torr, to remove the residual gas in reative cell.

Step 3, the preliminary treatment of AlN substrate surface.

H is passed in reative cell ₂carry out substrate surface preliminary treatment, gas flow 5sccm, reative cell vacuum degree 0.2Torr, underlayer temperature 1000 DEG C, processing time 8min.

Step 4, Graphene CVD epitaxial growth.

Ar and CH is passed in reative cell ₄, keep Ar and CH ₄flow-rate ratio be 6: 1, Ar flow 60sccm, CH ₄flow 10sccm, air pressure maintains 0.2atm, temperature 1050 DEG C, heating-up time 20min, retention time 80min.

Step 5, cooling procedure.

Temperature fall, to less than 100 DEG C, keeps Ar and CH in operation (3) ₄flow is constant, air pressure 0.2atm, completes the growth of Graphene.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (1)

1., based on the direct epitaxial growth method of Graphene CVD of AlN substrate, it is characterized in that,

Adopt Group III-V compound semiconductor AlN as substrate, by carrying out rational preliminary treatment to AlN substrate, growth regulation pressure, flow and temperature, direct growth Graphene on AlN, without the need to metal as catalyst, the Graphene of growth is directly used in and manufactures various device;

Its growing method performing step comprises as follows:

(1) AlN substrate is successively put into acetone, clean in ethanol and deionized water, each time 10-30min, takes out substrate, dries up with high pure nitrogen from deionized water;

(2) AlN substrate is put into chemical vapor deposition CVD reative cell, extracting vacuum to 10 ^-5-10 ^-6torr, to remove the residual gas in reative cell;

(3) in reative cell, H is passed into ₂carry out substrate surface preliminary treatment, gas flow 1-20sccm, reative cell vacuum degree 0.1-1Torr, underlayer temperature 900-1000 DEG C, processing time 5-10min;

(4) in reative cell, Ar and CH is passed into ₄, keep Ar and CH ₄flow-rate ratio be 10: 1-2: 1, Ar flow 20-200sccm, CH ₄flow 1-20sccm, air pressure maintains 0.2-1atm, temperature 1000-1100 DEG C, heating-up time 20-60min, retention time 50-100min;

(5) Temperature fall, keeps Ar and CH in operation (3) ₄flow is constant, air pressure 0.2-1atm, completes the growth of Graphene.