CN100449810C - Silicon based MgxZn1-xO ultraviolet electroluminescent device and method for producing the same - Google Patents

Abstract

The disclosed Si-based MgxZn1-xO UV electroluminescent device comprises: on Si substrate face, from bottom to top, an MgxZn1-xO thin film (0.1<x<0.3), SiO2 or Al2O3 thin film, and electrode; and the Ohm contact electrode on substrate back face. The preparation method comprises: cleaning substrate, sputtering growing for MgxZn1-xO film; using CVD or evaporating or sputtering or sol-gel method to deposit SiO2 or Al2O3 film; then, sputtering electrode on SiO2 film and Ohm contact electrode on back. This invention can adjust the relative content of Mg and Zn to change UV wavelength conveniently.

Description

A kind of silica-based Mg xZn 1-xO UV electroluminescence device and preparation method thereof

Technical field

The present invention relates to silica-based Mg _xZn _1-xO (0.1＜x＜0.3) UV electroluminescence device and preparation method thereof.

Background technology

In the recent period, because the development of photoelectric technology, the demand to Ultra-Violet Laser, high density storage and other short-wavelength light electric devices makes wide bandgap semiconductor receive increasing concern.ZnO at room temperature has the exciton bind energy of direct band gap and the 60meV of 3.37eV, makes it become the desired light electronic material of realizing ultra-violet light-emitting.1998, A.Ohtomo at first proposed, and mixes Mg and obtain Mg in ZnO _xZn _1-xThe O alloy can be so that its energy gap increases (list of references: A.Ohtomo, M.Kawasaki, T.Koida, K.Masubuchi, H.Koinuma, Y.Sakurai, Y.Yoshida, T.Yasuda and Y.Segawa, Appl.Phys.Lett.72,2466 (1998)).Studies show that afterwards guaranteeing Mg _xZn _1-xO not phase-splitting of alloy and keeping under the constant situation of hexagonal crystal system, the atom content of Mg can reach 37%, and energy gap increases to more than the 4.0eV thereupon simultaneously, and can regulate Mg by the content of regulating Mg _xZn _1-xThe energy gap of O alloy makes Mg _xZn _1-xThe O alloy becomes the adjustable ultraviolet light photo material of rising band gap (list of references: S.Choopun, R.D.Vispute, W.Yang, R.P.Sharma, T.Venkatesan, and H.Shen, Appl.Phys.Lett.80,1529 (2002); W.Yang, S.S.Hullavarad, B.Nagaraj, I.Takeuchi, R.P.Sharma, T.Venkatesan, R.D.Vispute and H.Shen, Appl.Phys.Lett.82,3424 (2003); I.Takeuchi, W.Yang, K.S.Chang, M.A.Arnova, T.Venkatesan, R.D.Vispute and L.A.Bendersky, J.Appl.Phys.94,7336 (2003); N.B.Chen and C.H.Sui, Materials Science and Engineering B 126,16 (2006)).Up to now, there has been the research the whole bag of tricks that worked to prepare Mg _xZn _1-xThe O film, such as: pulsed laser deposition (PLD), molecular beam epitaxy (MBE), metal-organic chemical vapor deposition equipment (MOCVD), magnetron sputtering, sol-gel etc., and to Mg _xZn _1-xThe pattern of O film is formed structure, and ultraviolet-visible absorbs, and character such as luminescence generated by light have carried out studying (list of references: J.W.Kim, H.S.Kang, J.H.Kim, S.Y.Lee, J.K.Lee and M.Nastasi, J.Appl.Phys.100,033701 (2006); H.Matsui, H.Tabata, N.Hasuike and H.Harima, J.Appl.Phys.99,024902 (2006); C.Y.Liu, Y.C.Liu, B.P.Zhang and R.Mu, Phys.Stat.Sol. (c) 3,3508 (2006); S.Kumar, V.Gupte and K.Sreenivas, J.Phys.:Condens.Matter 18,3343 (2006); D.Zhao, Y.Liu, D.Shen, Y.Lu, J.Zhangand X.Fan, J.Appl.Phys.90,5561 (2001)).But, also not about Mg _xZn _1-xThe electroluminescent report of O.

Summary of the invention

The objective of the invention is to propose a kind of simple silica-based Mg _xZn _1-xO UV electroluminescence device and preparation method thereof.

Silica-based Mg of the present invention _xZn _1-xThe O UV electroluminescence device is characterized in that depositing Mg from bottom to top successively in the front of silicon substrate _xZn _1-xO thin layer, 0.1＜x＜0.3, SiO ₂Or Al ₂O ₃Thin layer and electrode have Ohm contact electrode at the silicon substrate backside deposition.

The silica-based Mg of invention _xZn _1-xThe preparation method of O UV electroluminescence device may further comprise the steps:

1) be 0.005-50 ohm with resistivity. centimetre silicon substrate 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 that 10～30% MgZn alloy is a target with the atom content of Mg, 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 Mg _xZn _1-xThe O film, 0.1＜x＜0.3;

2) utilize chemical vapour deposition technique or evaporation or sputtering method or sol-gel process at Mg _xZn _1-xDeposit SiO on the O film ₂Or Al ₂O ₃Film;

3) at SiO ₂Or Al ₂O ₃Sputter semitransparent electrode on the film is at silicon substrate back spatter Ohm contact electrode.

Above-mentioned silicon substrate is a N type silicon chip.

The present invention can change Mg by regulating underlayer temperature and sputtering atmosphere _xZn _1-xThe crystalline state of O film changes Mg by adjusting sputtering time _xZn _1-xThe thickness of O film.

Beneficial effect of the present invention is: by the relative amount of Mg and Zn in the adjustment film, can regulate the wavelength of its UV electroluminescence.And 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).And, equipment that this preparation of devices method is used and existing mature silicon device plane process compatibility.

Description of drawings

Fig. 1 is silica-based Mg _xZn _1-xO UV electroluminescence device schematic diagram;

Fig. 2 is silica-based Mg _xZn _1-xThe electroluminescence spectrum that the O UV electroluminescence device obtains under different forward bias.

Embodiment

Further specify the present invention below in conjunction with drawings and Examples.

With reference to Fig. 1, the silica-based Mg of invention _xZn _1-xThe O UV electroluminescence device deposits Mg from bottom to top successively in the front of silicon substrate 1 _xZn _1-xO thin layer 2,0.1＜x＜0.3, SiO ₂Or Al ₂O ₃Thin layer 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 Mg of 300nm _xZn _1-xThe O film when sputter, adopts MgZn alloys target (atom content of Mg is 10%), 300 ℃ of underlayer temperatures, sputtering power 120W, passes 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: 4 precursor solution, and add an amount of HCl as catalyst, utilize sol-gel process at Mg _xZn _1-xSpin-on deposition thickness is about the SiO of 200nm on the O film 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 Mg of 300nm _xZn _1-xThe O film when sputter, adopts MgZn alloys target (atom content of Mg is 20%), 500 ℃ of underlayer temperatures, sputtering power 120W, passes 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 at Mg _xZn _1-xDeposit thickness is about the SiO of 100nm on the O film ₂Film, depositing temperature are 500 ℃, and operating pressure is 100Torr; 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 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 Mg of 300nm _xZn _1-xThe O film when sputter, adopts MgZn alloys target (atom content of Mg is 30%), 500 ℃ of underlayer temperatures, sputtering power 120W, passes to O ₂With Ar mist, O ₂With the flow-rate ratio of Ar be 1: 1, operating pressure is 5Pa; 2) be evaporation source with the sapphire particle, utilize electron beam evaporation method at Mg _xZn _1-xDeposit thickness is about the Al of 100nm on the O film ₂O ₃Film; 3) at Al ₂O ₃On 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

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 main glow peak is near 350nm, and this derives from Mg _xZn _1-xThe ultraviolet light emission that the nearly band edge transition of O (x=0.2) produces.

Claims (2)

1. silica-based Mg _xZn _1-xThe O UV electroluminescence device is characterized in that depositing Mg from bottom to top successively in the front of silicon substrate (1) _xZn _1-xO thin layer (2), 0.1＜x＜0.3, SiO ₂Or Al ₂O ₃Thin layer (3) and electrode (4) have Ohm contact electrode (5) at the silicon substrate backside deposition.

2. silica-based Mg according to claim 1 _xZn _1-xThe preparation method of O UV electroluminescence device 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 silicon substrate of 0.005-50 ohmcm cleans with resistivity, reative cell vacuum degree is evacuated to 1～5 * 10 ^-3Pa is that 10～30% MgZn alloy is a target with the atom content of Mg, 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 Mg _xZn _1-xThe O film, 0.1＜x＜0.3;

2) utilize chemical vapour deposition technique or evaporation or sputtering method or sol-gel process at Mg _xZn _1-xDeposit SiO on the O film ₂Or Al ₂O ₃Film;

3) at SiO ₂Or Al ₂O ₃Sputter semitransparent electrode on the film is at silicon substrate back spatter Ohm contact electrode.

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