CN103866272B - Method for improving P-type stability of zinc oxide film - Google Patents

Abstract

The invention discloses a method for improving the P-type stability of a zinc oxide film, which comprises the steps of putting a substrate into an ALD reaction chamber, heating the substrate and a chamber pipeline, and then carrying out multi-component composite deposition; the composite deposition comprises the steps of introducing doping deposition of a doping source containing a doping element Zr, zinc source deposition for the second time, nitrogen doping source deposition for the two times and oxygen source deposition for the two times respectively after zinc source deposition for the first time to form N-Zr-N codoping; the deposition sequence of the nitrogen doping source and the oxygen source is that the nitrogen doping source is deposited firstly, and then the oxygen source is deposited; the sequence of the doping source deposition containing the doping element Zr and the second zinc source deposition is that the second zinc source deposition is carried out firstly, and then the doping source deposition containing the doping element Zr is carried out. The method can carry out in-situ donor-acceptor co-doping on the zinc oxide film so as to increase the doping amount of acceptor elements and promote the p-type conversion of the zinc oxide film.

Description

Method for improving P-type stability of zinc oxide thin film

technical field

The invention relates to the technical field of preparation of zinc oxide thin films, in particular to a method for improving the P-type stability of zinc oxide thin films.

Background technique

Semiconductor thin films play a very important role in high-tech industries such as microelectronics, optics, and informatics. Develop high-quality semiconductor thin film preparation and doping technologies, especially for the preparation, characterization, and The study of doping and its characteristics is of great significance to important application fields for new energy, including ultraviolet-band luminescent materials, ultraviolet detectors, highly integrated photonics and electronic devices, and solar cells. Zinc oxide, as a new type II-VI group direct bandgap wide bandgap compound, has a large room temperature bandgap of 3.37eV, and the binding energy of free excitons is as high as 60meV, and it has attracted more and more attention as a semiconductor material. Compared with other wide-bandgap semiconductor materials, ZnO film has low growth temperature, good radiation resistance, low threshold power of stimulated radiation and high energy conversion efficiency. The key basic materials for high and new technologies to continue to develop after the 12th Five-Year Plan. However, due to the existence of defects in intrinsic ZnO, ZnO is n-type, and the preparation of p-type ZnO thin films is currently a hot and difficult point in ZnO-related research. Although the theoretical calculation of nitrogen doping makes the preparation of p-type ZnO possible, many experiments have shown that due to the low solid solubility of N element in ZnO, N element doping alone cannot achieve high carrier concentration and High mobility p-type ZnO thin film. In order to solve this problem, acceptor-donor-acceptor co-doping is considered to be one of the most promising directions for preparing high-quality p-ZnO thin films.

In recent years, methods for preparing ZnO thin films generally include: magnetron sputtering, metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), pulsed laser deposition (PLD) and wet chemical deposition. These preparation processes have their own advantages and disadvantages. From the crystallization situation, the film quality prepared by MOCVD and MBE method is better. However, MOCVD cannot perform in situ doping of thin films and the turbulence and gas flow distribution existing in the reaction will affect the thickness and uniformity of the film. Accurate doping of specific atomic layer positions by MBE technology is also difficult to achieve.

Contents of the invention

The technical problem to be solved by the present invention is to provide a kind of in-situ co-doping of zinc oxide film to increase the dosing amount of acceptor element and promote the p-type transition of zinc oxide film for improving the p-type transformation of zinc oxide film. method of stability.

In order to solve the above-mentioned technical problems, the present invention provides a method for improving the P-type stability of zinc oxide thin films, including putting the substrate into the ALD reaction chamber, heating the substrate and the chamber pipeline, and then performing multiple Composite deposition of components; the composite deposition includes, after the first zinc source deposition, respectively introducing a doping deposition of a doping source containing the doping element Zr, the second zinc source deposition, and two nitrogen doping sources deposition and two oxygen source depositions to form N-Zr-N co-doping; the deposition sequence of the nitrogen doping source deposition and the oxygen source deposition is first the nitrogen doping source deposition, and then the oxygen source deposition; The order of the doping source deposition of the heteroelement Zr and the second zinc source deposition is first the second zinc source deposition, and then the doping source containing the doping element Zr.

The method for improving the P-type stability of the zinc oxide thin film provided by the present invention utilizes the characteristics of layer-by-layer growth of atomic layer deposition. During the growth process of the zinc oxide thin film, two acceptor elements N and one Zr are added to form N - Zr-N co-doped zinc oxide thin films. The formation of N-Zr-N complex reduces the ionization energy and promotes the formation of p-type conductance. The preparation process of the invention is simple, the deposition and doping process is easy to control, and the prepared co-doped zinc oxide thin film is beneficial to improving the stability of the p-type electrical properties of the zinc oxide thin film.

Description of drawings

FIG. 1 is a flowchart of a method for improving P-type stability of a zinc oxide thin film provided by an embodiment of the present invention.

detailed description

Referring to Figure 1, the method for improving the P-type stability of the zinc oxide thin film provided by the embodiment of the present invention includes: treating a silicon substrate or a glass substrate with concentrated sulfuric acid hydrogen peroxide, and then ultrasonically cleaning it with ultrapure water , N ₂ blow dry, wherein concentrated sulfuric acid:hydrogen peroxide=4:1. Put the substrate into the atomic layer deposition chamber, turn on the atomic layer deposition equipment, adjust the working parameters, vacuumize and heat the bottom to achieve various working environments required for the experiment; conduct multiple groups of N-Zr co-doped zinc oxide thin films Composite deposition, namely Zn(C ₂ H ₅ ) ₂ /N ₂ /plasmaN ₂ /N ₂ /H ₂ O/N ₂ /Zn(C ₂ H ₅ ) ₂ /N ₂ /(CH ₃ CH ₂ O) ₄ Zr /N ₂ /plasmaN ₂ /N ₂ /H ₂ O/N ₂ =0.15s/50s/10s/50s/0.07s/50s/0.08s/50s/0.08s/50s/10s/50s/0.07s/50s. Wherein the flow rate of nitrogen is 1sccm-1000sccm, preferably 15sccm, the intake time is 0.04s-5s, preferably 0.15s, the cleaning time is 5s-150s, preferably 50s, and the substrate temperature is 100°C-500°C , preferably 300°C; where the plasma discharge power is 1W-100W, preferably 50W, and the discharge time is 1s-50s, preferably 10s. During this period, N doping was introduced by N ₂ plasma, Zr atoms were provided by (CH ₃ CH ₂ O) ₄ Zr, two depositions of plasmaN ₂ and one (CH ₃ CH ₂ O) ₄ Zr made Zr in ZnO replaces zinc (Zr _Zn ) and N replaces the position of O to form a N-Zr-N complex in the film, which can reduce the ionization energy and promote the formation of p-type conductance. By repeating the composite deposition of multiple components, the N-Zr-N co-doped zinc oxide film can be grown layer by layer.

The present invention grows Zr and N co-doped zinc oxide thin film by ALD layer-by-layer cycle growth mode, and the method is simple, utilizes the characteristics of single-layer cycle growth of atomic layer deposition, and realizes uniform growth of zinc oxide film in the whole film during the growth process. Doping in the structure, and the co-doped zinc oxide film is conducive to promoting the formation of p-type conductance.

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention without limitation, although the present invention has been described in detail with reference to examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (8)

1. the method for improving zinc-oxide film P type stability, it is characterised in that including:

Substrate is put in ALD reaction chamber, substrate and chamber tube are heated, then carry out multi-component composite deposition;

Described composite deposition includes after first time zinc source deposits, and introduces once the doping deposition of doped source containing doped chemical Zr, second time zinc source deposition, twice nitrogen doping source deposition and twice oxygen source deposition respectively, forms being co-doped with of N-Zr-N; The sedimentary sequence of described nitrogen doping source deposition and described oxygen source is first nitrogen doping source deposition, and rear oxygen source deposits; The described doped source deposition containing doped chemical Zr and described second time zinc source sedimentary sequence are first second time zinc source depositions, after doped source containing doped chemical Zr deposit; Described composite deposition includes:

Under vacuum conditions successively with first time zinc source, nitrogen doping source, oxygen source, second time zinc source, doped source containing doped chemical Zr, nitrogen doping source and oxygen source be deposited obtaining the N-Zr ZnO film being co-doped with, described first time zinc source, nitrogen doping source, oxygen source, doped source containing doped chemical Zr and second time zinc source open-assembly time in settling chamber are followed successively by 0.15s, 10s, 0.07s, 0.08s, 0.08s; Adopting high pure nitrogen to clean settling chamber after deposition every time, scavenging period is 50s.

2. preparation method according to claim 1, it is characterised in that described substrate is process through concentrated sulphuric acid and hydrogen peroxide, and through the silicon chip of the ultrasonic mistake of ultra-pure water, sapphire or glass, substrate surface is with hydroxyl.

3. the preparation method according to any one of claim 1-2, it is characterised in that described zinc source is the alkyl compound containing zinc or the halogenide containing zinc, and described oxygen source is water vapour or oxygen gas plasma; Described nitrogen doping source is N₂O��N₂��NO��NO₂Or NH₃Plasma.

4. preparation method according to claim 3, it is characterised in that the described halogenide containing zinc is zinc chloride ZnCl₂, the described alkyl compound containing zinc is diethyl zinc Zn (C₂H₅)₂Or zinc methide Zn (CH₃)₂��

5. preparation method according to claim 4, it is characterized in that, the described doped source containing doped chemical Zr is the halogenide containing Zr, the alcoholates containing Zr, the alkylates containing Zr, the hydride containing Zr, the cyclopentadienyl group containing Zr, the alkane amide containing Zr or the amidino groups containing Zr.

6. preparation method according to claim 5, it is characterised in that the described halogenide containing Zr is zirconium chloride ZrCl₄Or iodate zirconium ZrI₄, the described alcoholates containing Zr is ethanol zirconium (CH₃CH₂O)₄Zr or zirconium tert-butoxide C₁₆H₃₆O₄Zr��

7. the preparation method according to any one of claim 1-6, it is characterised in that also include:

The ratio of nitrogen doping source and oxygen in doping zinc-oxide thin film is regulated by controlling the duration of ventilation of described nitrogen doping source and steam.

8. preparation method according to claim 6, it is characterised in that also include:

The ratio of zirconium doped source and zinc in doping zinc-oxide thin film is regulated by controlling the duration of ventilation in doped source containing doped chemical Zr and zinc source.