Nano-line silicone carbide metal semiconductor field effect transistorTechnical field
The present invention relates to a kind of novel power semiconductor manufacturing technology.
Background technology
Traditional power device that occupies dominant position is the silicon power semiconductor.It is made with silicon materials.But because the band gap width of silicon materials is little, and the silicon non-refractory, thus the silicon power device when running into high temperature and use or during big electric current device can lose efficacy, cause serious consequence.So the additional cooling system of silicon device is very complicated, the operating cost height.
Carborundum is the ideal material of power semiconductor wafer, its advantage is: the forbidden band is wide, working temperature is high (can reach 600 ℃), Heat stability is good, on state resistance are little, good heat conductivity, that leakage current is minimum, PN junction is withstand voltage is high, helps producing resistant to elevated temperatures high-frequency high-power semiconductor device.
Sic semiconductor device is regarded as follow-on semiconductor power device, and various silicon carbide power switching devices are succeeded in developing in succession, though the silicon carbide power switching device had been obtained rapid progress in recent years, still also has a segment distance from large-scale commercial applicationsization.This situation why occurring, is that there are defectives such as microtubule in the carborundum crystals that is used for device because of growing silicon carbice crystals technology imperfection, makes device exist the low device cost that causes of rate of finished products to rise, even has potential safety hazard.So, the silicon carbide body material is as the core material of semiconductor device, and its application is severely limited.After must waiting for the growing technology full maturity of carborundum crystals, silicon carbide power device is come into the market fully.This is a road that is full of difficulty.Its fund expends huge, all drops into huge fund research in US and European country, to promote the development of this technology, obtains the phasic results of practical application.This can be found out by the achievement in research of U.S. CREE company.Last 40 years studies show that silicon carbide device depends on crystal technique because this will at high temperature carry out, be very difficult so get rid of the interference of various factors.
The objective of the invention is to adopt silicon carbide nanometer line to make the power metal semiconductor field effect transistor.The nano-line silicone carbide crystal that the present invention adopts is the carborundum crystals of diameter between 0.5-500nm, and it can have cube crystal structure or the brilliant structure of six reef knots.Purpose is to overcome that silicon carbide body material growing technology does not pass a test, restricts silicon carbide power device development bottle footpath and a kind of method that can substitute carborundum crystals made power semiconductor is provided, and a kind of like this product is provided.Because the silicon carbide nanometer line growing technology reaches high level, the silicon carbide nanometer line purity height of growth, crystal mass height, zero defect.So can be applied in the manufacturing of power metal semiconductor field effect transistor, form novel power metal semiconductor FET device.It has utilized silicon carbide nanometer line to have good characteristics such as the broad-band gap of body material carborundum, high temperature resistant, low on-resistance, adopts new construction to make Performances of Novel Nano-Porous rice noodles silicon carbide power device.
Nanometer technology is in fast-developing situation now.Nano electron device is born from nanometer technology and just causes showing great attention to of scientific circles and industrial quarters always.Since the calendar year 2001 world's ten big science and technology news report nano electron device successful operations, various countries scientific circles are all in the research of carrying out nano-transistor.Nano-wire transistor is wherein a kind of important nano electron device.Nano-wire transistor has overcome the weakness of conventional transistor owing to have good semiconductor property, and makes efficient and preparation means take place to change greatly, and making nano-wire transistor produce unprecedented application may.
Nano-line silicone carbide metal semiconductor field effect transistor is a kind of low power consuming, can adopt ultra-large integrated nano electron device.For this device is the field that national governments and industrial quarters are shown great attention to always.Because it directly affects the leadership of following information industry.We can say that who takes the good opportunity in this field, mean who just can microelectric technique or the nanoelectronic technical field occupy ascendancy.Following " system on a chip " directly depends on the progress achievement of nano electron device.High-temperature electronic device research now makes much progress.But adopting nano-line silicone carbide to make power device does not appear in the newspapers as yet.
The present invention can improve the operating temperature of device significantly with existing silicon power tube---silicon MESFET is compared.Traditional silicon power device can produce device degradation even fail result more than 300 degrees centigrade 200 degrees centigrade of operations down.The operation but device of the present invention can do as usual when reaching more than 600 degrees centigrade, and can not produce fail result.Though the silicon power device is being ruled existing power device market, yet for general power supply control, its optional equipment is many and complicated, and main purpose is to be cooling.Because the heat radiation of silicon is more than the carborundum difference, therefore, the heat radiation of silicon carbide nanometer line power device is very fast.Be not easy to cause heat accumulation.Secondly, the withstand voltage and resistance to elevated temperatures of silicon carbide nanometer line power device is more much higher than silicon device.And can be along with process adjustments.This is that silicon technology is not available.In addition, owing to be nanoscale devices, be easy to integratedly, have intelligent and systemic feature more.This may have great importance for reducing silicon power device manufacturing cost.It has saved the space, makes device can do forr a short time, is more suitable for computer, the optional equipment of small-sized or miniature electronic instrument such as hand portable equipment and personal assistant.
Summary of the invention
The present invention can realize by kinds of processes. the technology that occurs has at present, by microoperation technologies such as scanning-tunnelling probe microscope or atomic force microscope; The photoetching process technology.They can construct nano-wire transistor.Although various informative, all be nano-wire transistor.Our nano-line silicone carbide metal semiconductor field effect transistor invention is to reach by following measure.At first, preparation is through the manufacturing silicon carbide semiconductor nano wire of overdoping.These doped nanowire are divided into three types, and the one, the N type mixes, and the 2nd, the P type mixes, and the 3rd, undope.Nano wire is meant the crystal of fiber, whisker, crystal column and the line of diameter between 0.5nm-500nm, and nanometer silicon carbide exists various many types of, can be a cube crystal structure, also can be the brilliant structures of six reef knots, such as, 2H, 4H, 6H, 15R are many types of etc.On substrates such as silicon wafer, quartz plate, silicon carbide wafer or corundum, directly deposit one deck silicon oxide film can adopt the way of microcontroller fluid that silicon carbide nanometer line is arranged in parallel thereon; Also can directly on these semi-insulating wafers, directly adopt dispersion technology that nano wire is arranged in parallel.Apply photoresist, adopt the optical semiconductor carving technology again, according to designed photo etched mask domain structure form, scribe device electrode, depositing metal in vacuum thermal resistance stove forms source electrode, drain electrode, grid, is respectively source, leakage, the grid of metal-semiconductor field effect transistor; Also can form source electrode, drain electrode earlier, adopt photoetching process to prepare grid again.After finishing this technology, the silicon oxide deposition film also can deposition silicon nitride film or other High Performance Insulation material film, air locking.Such device is exactly the silicon carbide nanometer line metal-semiconductor field effect transistor, according to the needs of nano-line silicone carbide field-effect transistor in circuit, disposes various external lead wires to it.Wherein the photoetching process of semiconductor technology can be electron beam lithography, ultraviolet etching or synchrotron radiation.Another characteristics are, when drawing grid, can be the metal slices, also can be nano-line silicone carbides.
Embodiment
Embodiment 1. single nano-line silicone carbide metal semiconductor field effect transistor manufacturings.
An example of the present invention is that the employing diameter is 10nm, and length is the single nano-line silicone carbide metal semiconductor field effect transistor of the nano-line silicone carbide manufacturing of 70nm.The silicon carbide nanometer line of nano-line silicone carbide material for mixing through nitrogen is separated into single nano wire state with dispersion liquid, is laid on the semi-insulating substrate of silicon carbide wafer.Employing comprises the reticle that three electrodes have the external lead wire patterning.The electrode arrangement order is source electrode, grid, drain electrode.Electrode spacing is 15nm.Apply photoresist, use ultraviolet photoetching, steam in the thermal resistance vacuum furnace then and cross metal electrode, the electrode material is a palladium metal, forms three electrodes, i.e. source electrode, gate electrode and drain electrode.Behind the electrode connection, silicon oxide deposition film on electrode, on silica in the middle of the source leakage electrode structure depositing metal gold.Deposition silicon nitride film then, air locking.Can make nano-line silicone carbide metal semiconductor field effect transistor device cell and other technology manufacturing nano-line silicone carbide metal semiconductor field effect transistor monolithic integrated circuit or blend together integrated circuit in conjunction with this technology.Device performance: in temperature is under 600 ℃, and device still moves normally.The device power density is 2.8W/mm, and cut-off frequency is 8GHz.
Embodiment 2 Donna rice noodles silicon carbide metal-semiconductor field effect transistors.
Nitrating nanometer line carborundum is arranged in parallel within on the semi-insulating substrate of silicon carbide wafer.Construct a Donna rice noodles silicon carbide metal-semiconductor field effect transistors.Be to contain two above nano-line silicone carbides in the metal-semiconductor field effect transistor unit.Carry out Donna rice noodles silicon carbide metal-semiconductor field effect transistors structure according to the technology of embodiment 1.In this example in the metal-semiconductor field effect transistor unit nano-line silicone carbide have 107.Device performance: 600 ℃ operation is normal down for temperature.Power density is 60W/mm, and cut-off frequency is 12GHz.