CN100353578C - UV electroluminescence device of silicon base zinc oxide and preparation process thereof - Google Patents

Abstract

The present invention discloses a UV electroluminescence device made of silicon base zinc oxide and a preparing method thereof. The UV electroluminescence device made of silicon base zinc oxide is characterized in that a ZnO film, a SiO2 film and electrodes are deposited on the front side of a silicon base from bottom to top, and ohmic contact electrodes are deposited on the back side of the silicon base. The preparing method of the UV electroluminescence device made of silicon base zinc oxide comprises the following steps: firstly, an N type silicon chip is put into a reaction chamber of a DC reactive magnetron sputtering device after the N type silicon chip is cleaned, the reaction chamber is evacuated in a vacuum state, Zn is adopted as target materials, O2 and Ar are adopted as the sputtering atmosphere, and the sputtering growth is carried out to obtain the ZnO film; secondly, the SiO2 film is deposited on the ZnO film through a chemical vapor deposition technique, or an evaporation technique, or a sputtering technique or a sol-gel technique; finally, the electrodes are sputtered on the SiO2 film, and the ohmic contact electrodes are spattered on the back side of the silicon base. The UV electroluminescence device made of silicon base zinc oxide of the present invention has simple structure, simple realizing method and no need of a P type film, and thus, the problem that the P type film is difficult to dope into the ZnO film is avoided. Apparatuses used by the preparing method of the UV electroluminescence device made of silicon base zinc oxide have compatibility with the existing mature silicon device planar technology.

Description

A kind of UV electroluminescence device of silicon base zinc oxide and preparation method thereof

Technical field

The present invention relates to UV electroluminescence device of silicon base zinc oxide and preparation method thereof.

Background technology

Because ZnO at room temperature has the exciton bind energy of direct band gap and the 60mev of 3.37eV, so it is a desirable photoelectron material of realizing ultra-violet light-emitting.But the electricity of ZnO causes ultraviolet light-emitting diode and laser diode is difficult to realize, the biggest obstacle that it runs into is that the P type doping of ZnO high concentration exists suitable difficulty.In order to avoid this difficulty, people had once attempted the electroluminescence of multiple heterojunction structure with the realization zno-based, as: n-ZnO/p-GaN, p-AlGaN/n-ZnO and p-SrCu ₂O ₂/ n-ZnO, the report document has: Ya.I.Alivov, J.E.Van Nostrand, D.C.Look, M.V.Chukichev, and B.M.Ataev, Appl.Phys.Lett.83,2943 (2003); Ya.I.Alivov, E.V.Kalinina, A.E.Cherenkov, D.C.Look, B.M.Ataev, A.K.Omaev, M.V.Chukichev, D.M.Bagnall, Appl.Phys.Lett.83,4719 (2003); H.Ohta, M.Orita, and M.Hirano, and H.Hosono, J.Appl.Phys.89,5720 (2001).At the homogeneity LED aspect of ZnO, people such as Toru Aoki have reported with laser doping and have realized the ZnO diode, and obtained ultra-violet light-emitting (list of references T.Aoki under 110K, Y.Hatanaka, and D.C.Look, Appl.Phys.Lett.76,3257 (2000)); People such as Xin-Li Guo utilize N ₂O plasma intensifier pulse laser reactive sedimentation has realized that the P type of ZnO mixes, thereby obtains the ZnO light-emitting diode, but at luminous very faint (the list of references X.L.Guo of ultraviolet region, J.H.Choi, H.Tabata, and T.Kawai, Jpn.J.Appl.Phys.40, L177 (2001)); People such as Atsushi Tsukazaki have reported that repeated temperature modulation epitaxy realizes that the P type mixes, thereby prepared the ZnO diode, and obtained electroluminescence from ultraviolet to the green glow zone, yet luminous still more weak (list of references A.Tsukazaki, A.Ohtomo, the T.Onuma of ultraviolet region, M.Ohtani, T.Makino, M.Sumiya, K.Ohtani, S.F.Chichibu, S.Fuke, Y.Segawa, H.Ohno, H.Koinuma, and M.Kawasaki, NatureMater.4,42 (2005)).Under but the practicability P of ZnO type mixes the situation that does not also have at present thoroughly to solve, adopt MIS structure to remain the electroluminescent approach of ZnO that realizes based on ZnO.In fact, just reported the ultra-violet light-emitting of Ag/SiO/ZnO and Au/SiO/ZnO structure in the 1970's, should be noted that, what adopt in these structures is the ZnO monocrystal, and luminous (the list of references B.W.Thomas and D.Walsh that under high bias voltage (tens volts even 200V), produces, Electron.Lett.9,362 (1973); T.Minami, M.Tanigawa, M.Yamanishi, and T.Kawamura, Jpn.J.Appl.Phys.13,1475 (1974)).Recently, people such as Ya.I.Alivov utilizes the nitrogen ion to be infused in Al ₂O ₃Form insulating barrier in the base n type ZnO film, thereby form zno-based MIS structure and obtained ultra-violet light-emitting (list of references Ya.I.Alivov, D.C.Look, B.M.Ataev, M.V.Chukichev, V.V.Mamedov, V.I.Zinenko, Yu.A.Agafonov, and A.N.Pustovit, Solid-State Electron.48,2343 (2004)).Up to the present, some progress have been obtained though cause the exploitation of ultra-violet light-emitting device based on the electricity of ZnO, but all adopted comparatively complicated implementation method, such as: prepare P type compound semiconductor film with molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition equipment (MOCVD) method.

Summary of the invention

The objective of the invention is to propose a kind of simple UV electroluminescence device of silicon base zinc oxide and preparation method thereof.

UV electroluminescence device of silicon base zinc oxide of the present invention is characterized in that depositing ZnO film, SiO from bottom to top successively in the front of silicon substrate ₂Film and electrode have Ohm contact electrode at the silicon substrate backside deposition.

The preparation method of the UV electroluminescence device of silicon base zinc oxide of invention may further comprise the steps:

1) be 0.005-50 ohm with resistivity. centimetre N type silicon chip put into the reative cell of direct current reaction magnetron sputtering device after cleaning, reative cell vacuum degree is evacuated to 1～5 * 10 ^-3Pa is a target with Zn, with O ₂With Ar as sputtering atmosphere, O ₂With the flow-rate ratio of Ar be O ₂: Ar=1: 2～1: 5, under 10～20Pa pressure, underlayer temperature is 300 ℃～600 ℃, carries out the sputter growth, obtains ZnO film;

2) utilize conventional chemical vapour deposition technique or evaporation or sputtering method or sol-gel process on ZnO film, to deposit SiO ₂Film;

3) at SiO ₂Sputter semitransparent electrode on the film is at N type silicon substrate back spatter Ohm contact electrode.

Above-mentioned semitransparent electrode can be the thick golden film of ito thin film or 2-10nm.

The present invention can change the crystalline state of ZnO film by the adjusting underlayer temperature, by adjusting the thickness that sputtering time changes ZnO film.

Beneficial effect of the present invention is: the structure and the implementation of device are simple, do not need to adopt complicated molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition equipment means such as (MOCVD).This device need not to adopt P type ZnO film, thereby has avoided the problem of ZnO film P type doping difficulty.In addition, used equipment and the existing mature silicon device plane process compatibility of this preparation of devices method.

Description of drawings

Fig. 1 is the UV electroluminescence device of silicon base zinc oxide schematic diagram;

Fig. 2 is the electroluminescence spectrum that UV electroluminescence device of silicon base zinc oxide obtains under different forward bias.

Embodiment

Further specify the present invention below in conjunction with accompanying drawing.

With reference to Fig. 1, the UV electroluminescence device of silicon base zinc oxide of invention deposits ZnO film 2, SiO from bottom to top successively in the front of silicon substrate 1 ₂ Film 3 and electrode 4 have Ohm contact electrode 5 at the silicon substrate backside deposition.

Embodiment 1

Take following processing step: 1) clean N type＜100 〉, resistivity is 0.005 ohm. centimetre, size is 15 * 15mm ², thickness is 675 microns silicon chip, puts into the reative cell of direct current reaction magnetron sputtering device after the cleaning, reative cell vacuum degree is evacuated to 1 * 10 ^-3Pa; On silicon chip, utilize the method deposit thickness that reacts direct current sputtering to be about the ZnO film of 300nm, when sputter, adopt Zn target, 300 ℃ of underlayer temperatures, sputtering power 120W, pass to O ₂With Ar mist, O ₂With the flow-rate ratio of Ar be 1: 2, operating pressure is 10Pa; 2) adopting mol ratio is positive tetraethyl orthosilicate (TEOS): ethanol (EtOH): H ₂O=1: 10: 10 precursor solution, and add an amount of HCl as catalyst, utilize so-gel method spin-on deposition thickness on ZnO film to be about the SiO of 200nm ₂Film, after the spin coating 80 ℃ of down oven dry 20 minutes, then 650 ℃ of heat treatments 2 hours under oxygen; 3) at SiO ₂On the film and the silicon substrate back side is sputter 10nm and the thick Au film of 100nm, wherein the former area 10 * 10mm respectively ²

Embodiment 2

Take following processing step: 1) clean N type＜100 〉, resistivity is 0.5 ohm. centimetre, size is 15 * 15mm ², thickness is 675 microns silicon chip, puts into the reative cell of direct current reaction magnetron sputtering device after the cleaning, reative cell vacuum degree is evacuated to 5 * 10 ^-3Pa; On silicon chip, utilize the method deposit thickness that reacts direct current sputtering to be about the ZnO film of 300nm, when sputter, adopt Zn target, 500 ℃ of underlayer temperatures, sputtering power 120W, pass to O ₂With Ar mist, O ₂With the flow-rate ratio of Ar be 1: 3, operating pressure is 20Pa, 2) with SiO ₂Be target, utilize RF sputtering method deposit thickness on ZnO film to be about the SiO of 100nm ₂Film, sputtering power are 100W, and working gas is an argon gas, and operating pressure is 10Pa; 3) at SiO ₂The thick ito thin film of sputtering sedimentation 50nm on the film is at the thick Au film of silicon substrate back spatter 100nm, wherein the former area 10 * 10mm ²

Embodiment 3

Take following processing step: 1) clean N type＜100 〉, resistivity is 50 ohm. centimetre, size is 15 * 15mm ², thickness is 675 microns silicon chip, puts into the reative cell of direct current reaction magnetron sputtering device after the cleaning, reative cell vacuum degree is evacuated to 3 * 10 ^-3Pa; On silicon chip, utilize the method deposit thickness that reacts direct current sputtering to be about the ZnO film of 300nm, when sputter, adopt Zn target, 500 ℃ of underlayer temperatures, sputtering power 120W, pass to O ₂With Ar mist, O ₂With the flow-rate ratio of Ar be 1: 3, operating pressure is 20Pa; 2) be source of the gas with positive tetraethyl orthosilicate (TEOS), utilize chemical gaseous phase depositing process deposit thickness on ZnO film to be about the SiO of 100nm ₂Film, depositing temperature are 500 ℃, and operating pressure is 100Torr; 3) at SiO ₂The thick ito thin film of sputtering sedimentation 50nm on the film is at the thick Au film of silicon substrate back spatter 100nm, wherein the former area 10 * 10mm ²

Fig. 2 has provided the different driving voltage/current electroluminescence (EL) down that the device that obtains by said method at room temperature records and has composed, and during forward bias, negative pressure is added on the silicon substrate.As can be seen from the figure, along with the increase of current/voltage, electroluminescent intensity is also along with increase, and this is typical electroluminescent feature.In addition, the position of glow peak is near 388nm, and this derives from the ultraviolet light emission that the nearly band edge transition of ZnO produces.

Claims (2)

1. UV electroluminescence device of silicon base zinc oxide is characterized in that depositing ZnO film (2), SiO from bottom to top successively in the front of silicon substrate (1) ₂Film (3) and electrode (4) have Ohm contact electrode (5) at the silicon substrate backside deposition.

2. the preparation method of UV electroluminescence device of silicon base zinc oxide according to claim 1 is characterized in that may further comprise the steps:

1) be the reative cell of putting into the direct current reaction magnetron sputtering device after the N type silicon chip of 0.005-50 ohmcm cleans with resistivity, reative cell vacuum degree is evacuated to 1～5 * 10 ^-3Pa is a target with Zn, with O ₂With Ar as sputtering atmosphere, O ₂With the flow-rate ratio of Ar be O ₂: Ar=i: 2～1: 3, under 10～20Pa pressure, underlayer temperature is 300 ℃～500 ℃, carries out the sputter growth, obtains ZnO film;

2) utilize chemical vapour deposition technique or evaporation or sputtering method or sol-gel process on ZnO film, to deposit SiO ₂Film;

3) at SiO ₂Sputter semitransparent electrode on the film is at N type silicon substrate back spatter Ohm contact electrode.

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