CN101235457A - N2O doping p-type Zn1-xCoxO diluted magnetic semi-conductor thin film and preparation method thereof - Google Patents

Abstract

The invention relates to a method for doping growing p type Zn1-xCoxO diluted magnetic semi-conducting thin film by N2O and a pulsed laser deposition method is adopted. Target material is a ceramic target which is produced through mixing and sintering ZnO and Co2O3 powder, wherein the molar content x of the Co is 0<x<=10%. The method comprises: arranging a substrate after washing into a growth chamber of a pulsed laser deposition device, abstracting the growth chamber to vacuum, growing under the N2O atmosphere that the pressure intensity is2-15Pa, and the growth temperature is 300-700DEG C. The method of the invention is simple, the p type doping concentration can be controlled through adjusting N2O gas pressure, and simultaneously the p type Zn1-xCoxO diluted magnetic semi-conducting thin film which is prepared by the invention is provided with the performance and the magnetic performance of semiconductors. The carrier concentration is 10<15>-10<18>cm-3.

Description

N 2O doped p type Zn 1-xCo xO diluted semi-conductor thin-film and preparation method thereof

Technical field

The present invention relates to p type Zn _1-xCo _xThe growth method of O diluted semi-conductor thin-film, especially N ₂O doped growing p type Zn _1-xCo _xThe method of O diluted semi-conductor thin-film.

Background technology

Dilute magnetic semiconductor (DMS) material is a doped magnetic ion in non magnetic semi-conductor (as IV-VI family, II-VI family or III-V family), utilizes carrier control technique to produce the new function material of magnetic.Since magnetic ion local magnetic moment with can be charged the son spin have exchange interaction, therefore can effectively control their photoelectricity, magnetic, photoabsorption and characteristic such as transport by changing magnetic impurity concentration and foreign field intensity.DMS has used elementary charge and spin character simultaneously, therefore can be directly and the conventional semiconductor device integrated, can be used for preparing various ultra-low calories consume highdensity message memory, logic device and spin polarized optical transmitting set etc. integrated the new device of light, electricity, magnetic function.

The research of zno-based DMSs material also is in the fundamental research stage, research emphasis aspect material preparation is to introduce transition metal (TM) ionic replacement zine ion (Zn) by physics or chemical preparation process to realize its magnetic, because TM ionic radius and Zn ion are more or less the same, enter the lattice of ZnO easily; TM 3d electronic orbit is in the state of not filling up, spin between TM ion coupling exchange interaction or may be that its magnetic is originated by the spin coupling exchange interaction that electronics (hole) is regulated.

If can prepare the application that controlled p type zno-based diluted semi-conductor thin-film will be expected to open up zno-based dilute magnetic semiconductor device.Though many paper reports of zno-based diluted semi-conductor thin-film performance study are arranged at present, still do not have the report of preparation p type zno-based diluted semi-conductor thin-film.

Summary of the invention

The purpose of this invention is to provide a kind of N ₂O doped p type Zn _1-xCo _xO diluted semi-conductor thin-film and preparation method thereof.

N of the present invention ₂O doped growing p type Zn _1-xCo _xO diluted semi-conductor thin-film, its carrier concentration are 10 ¹⁵～10 ¹⁸Cm ^-3, the molar content x of Co is 0＜x≤10%.

N ₂O doped growing p type Zn _1-xCo _xThe method of O diluted semi-conductor thin-film, employing be pulsed laser deposition, may further comprise the steps:

1) the pure ZnO of weighing, Co ₂O ₃Powder, wherein the molar content x of Co is 0＜x≤10%, with above-mentioned powder ball milling mix, compression moulding, at 1000～1300 ℃ of sintering temperatures, make the Zn that mixes Co then _1-xCo _xThe O ceramic target;

2) ceramic target that step 1) is made is put into pulsed laser deposition device growth room with the substrate that cleaned, and keeping the distance between target and the substrate is 4～6cm, and growth room's vacuum tightness is evacuated to 10 at least ^-3Pa, substrate heat to 300～700 ℃, and the growth room feeds N ₂O gas, control pressure is 2～15Pa, opens laser apparatus, allows laser beam focus on target surface ablation target, is deposited on the substrate, obtains N ₂O doped p type Zn _1-xCo _xThe O diluted semi-conductor thin-film is cooled to room temperature with film under the 50Pa oxygen atmosphere.

Among the present invention, the purity of ZnO 〉=99.99%, Co ₂O ₃Purity 〉=99.99%.Said substrate can be silicon or sapphire or zinc oxide or quartz or glass.

Beneficial effect of the present invention is:

1) method is simple, and p type doping content can be by regulating N ₂The O gas pressure intensity is controlled;

2) at Zn _1-xCo _xRealize being subjected to the real-time doping of main N in the O crystal film process of growth;

3) N of the present invention's growth ₂O doped p type Zn _1-xCo _xThe O diluted semi-conductor thin-film has semi-conductive performance and magnetic performance simultaneously.

Description of drawings

Fig. 1 is the pulsed laser deposition device synoptic diagram that adopts according to the inventive method, and among the figure: 1 is laser apparatus; 2 is the growth room; 3 is target; 4 is substrate.

Embodiment

The present invention is further illustrated below in conjunction with example.

Embodiment 1

With glass is substrate growth N ₂O doped p type Zn _1-xCo _xThe O diluted semi-conductor thin-film, concrete steps are as follows:

1) the preparation weighing purity of ceramic target is 99.99% ZnO, Co ₂O ₃Powder, wherein the molar content of Co is 5%.With load weighted ZnO, Co ₂O ₃Powder is poured in the ball grinder that agate ball is housed, and ball milling is 15 hours on ball mill, and purpose is with ZnO, Co ₂O ₃Powder mixes is also refinement to a certain extent evenly.Then raw material is separated and dried, add binding agent and grind compression moulding.The idiosome of moulding is put into sintering oven, and row is plain through low temperature (800 ℃), makes the binding agent volatilization, is warming up to 1200 ℃ of sintering again 2 hours, obtains mixing the Zn of Co _0.95Co _0.05The O ceramic target.

2) preparation of film will be mixed the Zn of Co _0.95Co _0.05The O ceramic target is contained on the target frame, embeds then in the target holder of pulsed laser deposition device.Glass substrate is fixed on the sample table after cleaning, puts into growth room 2.The distance of regulating substrate 4 and target 3 is 4.5cm, and with baffle plate substrate and target is separated.Growth room's vacuum tightness is evacuated to 2 * 10 ^-3Pa, substrate are heated to 500 ℃ of film growth temperature, feed N ₂O gas, pressure is controlled at 15Pa.Open laser apparatus 1 (pulsed laser energy is 280mJ, frequency 5Hz), pre-deposition 5min removes staining of target material surface, the baffle plate of outwarding winding then, deposit film.Substrate and target low speed rotation in the deposition process are to improve the homogeneity of film.Depositing time is 40min, the thick 200nm that is about of film.The growth ending rear film slowly cools to room temperature under the oxygen protection of 50Pa.The N that this example makes ₂The O doping of Zn _0.95Co _0.05The O diluted semi-conductor thin-film shows p type conduction: resistivity is 1313 Ω cm, and hole concentration is 4.14 * 10 ¹⁵Cm ^-3, hall mobility is 1.34cm ²/ V.s, and have magnetic through SQUID test.

Embodiment 2

The preparation method is with embodiment 1, and difference is that the molar content of Co is 1%, control N ₂The O gas pressure intensity is 10Pa.The N that this example makes ₂The O doping of Zn _0.99Co _0.01The O diluted semi-conductor thin-film shows p type conduction: resistivity is 250.4 Ω cm, and hole concentration is 4.04 * 10 ¹⁷Cm ^-3, hall mobility is 0.874cm ²/ V.s, and have magnetic through SQUID test.

Embodiment 3

The preparation method is with embodiment 1, and difference is that the molar content of Co is 10%, the N that this example makes ₂The O doping of Zn _0.90Co _0.10The O diluted semi-conductor thin-film shows p type conduction: resistivity is 1834cm, and hole concentration is 2.31 * 10 ¹⁵Cm ^-3, hall mobility is 1.717cm ²/ V.s, and have magnetic through SQUID test.

Claims (3)

1.N ₂O doped p type Zn _1-xCo _xThe O diluted semi-conductor thin-film, the carrier concentration that it is characterized in that this film is 10 ¹⁵～10 ¹⁸Cm ^-3, the molar content x of Co is 0＜x≤10%.

2. N according to claim 1 ₂O doped p type Zn _1-xCo _xThe preparation method of O diluted semi-conductor thin-film may further comprise the steps:

1) the pure ZnO of weighing, Co ₂O ₃Powder, wherein the molar content x of Co is 0＜x≤10%, with above-mentioned powder ball milling mix, compression moulding, at 1000～1300 ℃ of sintering temperatures, make the Zn that mixes Co then _1-xCo _xThe O ceramic target;

2) ceramic target that step 1) is made is put into pulsed laser deposition device growth room with the substrate that cleaned, and keeping the distance between target and the substrate is 4～6cm, and growth room's vacuum tightness is evacuated to 10 at least ^-3Pa, substrate heat to 300～700 ℃, and the growth room feeds N ₂O gas, control pressure is 2～15Pa, opens laser apparatus, allows laser beam focus on target surface ablation target, is deposited on the substrate, obtains N ₂O doped p type Zn _1-xCo _xThe O diluted semi-conductor thin-film is cooled to room temperature with film under the 50Pa oxygen atmosphere.

3. N according to claim 2 ₂O doped p type Zn _1-xCo _xThe preparation method of O diluted semi-conductor thin-film is characterized in that said substrate is silicon or sapphire or zinc oxide or quartz or glass.

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