TWI440175B - Semiconductor device having zinc oxide film - Google Patents

Description

Semiconductor component having a zinc oxide film

The present invention relates to a semiconductor component having a zinc oxide thin film, and more particularly to a semiconductor component having a zinc oxide thin film having a different carrier type.

Pure zinc oxide has a low electrical conductivity because the electron density in the film is low and cannot be used as a good conductor. However, when impurities are doped therein, an improvement in electrical properties and optical properties can be obtained. Zinc oxide is a common transparent N-type semiconductor material having a wide band gap (Eg) of about 3.3 eV. Zinc oxide has been used as a thin film electrode for different optoelectronic component applications, such as solar cells or light-emitting diodes. When zinc oxide is doped with impurities, the range of sheet resistance is lowered, and it can also be applied to a transparent conductive film in a well-known semiconductor process technology, when combined with other transparent oxide films such as indium tin oxide (ITO) or dioxide. When tin oxide is compared, the cost is relatively low.

However, due to the poor solubility of the zinc oxide film on the P-type dopant, the dopant is not easy to enter the film, and the defect of the zinc oxide film itself makes the film property tend to be biased toward the N-type, so that high stability and high hole load cannot be produced. The sub-concentration P-type zinc oxide film is applied to the market. Therefore, if a stable P-type zinc oxide transparent electrode can be developed, a PN junction can be formed with the N-type electrode, which can be applied to a wide range of fields, such as forming a transparent photovoltaic element having a PN junction. It can also replace the current P-type hole injection layer of organic light-emitting diode (OLED) or the electrode fabrication of solar cells, and further can make a film material of blue light and violet light-emitting diode, and can be applied to white light in the future. The excitation source of the diode or the semiconductor laser of short wavelength, it is known that the zinc oxide film has great application potential in the field of short-wavelength photovoltaic elements.

At present, in the production of P-type zinc oxide, most of the nitrogen (N) element dopants of the five elements are used in the zinc oxide film to fill the oxygen vacancy in the zinc oxide film to increase the concentration of the hole, but due to the nitrogen The solubility of (N) elemental dopants in zinc oxide is low, so the conventional film formation method cannot produce stable and high concentration of P-type zinc oxide, and the nitrogen atoms are not easily dissolved in the zinc oxide film, so that the P-type zinc oxide film is fabricated. Not easy. And the activation process uses a high-temperature furnace, which will cause a thermal budget effect during long-term temperature rise or heat activation treatment to increase the oxygen vacancy density in the zinc oxide film, resulting in a decrease in hole concentration or difficulty in producing a stable P-type zinc oxide. U.S. Patent Publication Nos. US200900011363 and US20080164466 are subjected to a high temperature furnace or a heating annealing step.

U.S. Patent No. 6,624,442, the N-type zinc oxide layer 12 is grown on the substrate 11 by pulsed laser evaporation (PLD), and the Zn ₃ P ₂ film 13 is plated on the N-type zinc oxide layer 12, as shown in FIG. The Zn ₃ P ₂ film 13 is irradiated by the laser 14, the weak bond of Zn ₃ P ₂ is thermally dissociated to form Zn and P atoms, and the P atoms are diffused into the N-type zinc oxide layer 12 to form P-type zinc oxide and PN. The junction can be used to fabricate semiconductor components. However, the laser used in this method cannot completely decompose the Zn ₃ P ₂ film 13 on the N-type zinc oxide layer 12 and is uniformly diffused into the N-type zinc oxide layer 12 to form P-type zinc oxide. There is a residual Zn ₃ P ₂ film 13 on the zinc oxide layer 12, and the depth of diffusion of Zn ₃ P ₂ cannot be effectively controlled, and the above-mentioned unstable factors will affect the performance of the semiconductor element.

One embodiment of the invention discloses a semiconductor device having a zinc oxide thin film comprising a substrate and a dopant-containing zinc oxide film. The zinc oxide film is disposed on the substrate, and the zinc oxide film includes at least two regions having different carrier types.

One embodiment of the invention discloses a semiconductor device having a zinc oxide thin film comprising a substrate and a dopant-containing zinc oxide film. The zinc oxide film is disposed on the substrate and partially includes at least one region of the activated dopant.

The technical features of the present disclosure have been briefly described above, so that a detailed description of the present disclosure will be better understood. Other technical features that form the subject matter of the claims of the present disclosure will be described below. It is to be understood by those of ordinary skill in the art that the present invention disclosed herein may be It is also to be understood by those of ordinary skill in the art that this invention is not limited to the spirit and scope of the disclosure disclosed in the appended claims.

Fig. 2 illustrates a sputtering system for forming a zinc oxide thin film according to an embodiment of the present invention. In the vacuum chamber 21 of the sputtering system 20, two sputtering sources 22 and 23 are provided, and the two sputtering sources 22 and 23 respectively use an aluminum nitride (AlN) target 221 and a zinc oxide target 231. . The power of the two sputtering sources 22 and 23 is separately controlled, and the ratio of the composition of zinc oxide to aluminum nitride in the film formed on the substrate 24 after sputtering can be adjusted. In addition, the wattage of the aluminum nitride target 221 can be fixed, and the growth of the zinc oxide film on the substrate 24 can be performed under a nitrogen atmosphere to effectively control the ratio of the group III to the group V. Further, the substrate 24 is fixed to the test piece holder 25 of the sputtering system 20, and the double target of the aluminum nitride target 221 and the zinc oxide target 231 is grown and doped nitridation without heating the substrate. An aluminum zinc oxide (ZnO:AlN) film 26 is on the substrate 24.

In addition to the aluminum nitride (AlN) of the above III-V element compound as a target of the dopant, gallium nitride (GaN) or indium nitride (InN) can also be used as a target for the dopant. In addition, the dopant may also be lithium (Li), sodium (Na) or potassium (K) of the group IA; gold (Au), silver (Ag), copper (Cu) of the group IB element; nitrogen of the compound of the group IV element Lithium nitride (LiN), silver nitride (NAg) or phosphorus nitride (NP); or magnesium nitride (MgN) of a Group II-V element compound.

In this embodiment, a zinc oxide film 26 doped with aluminum nitride is formed by a sputtering method, and the film may be formed by an Atomic Layer Deposition (ALD) method or an Organometallic Chemical Vapor Deposition (MOCVD) method.

Fig. 3 illustrates a system for activating a zinc oxide thin film according to an embodiment of the present invention. Since the zinc oxide film 26 which is initially plated and grown is arranged in a disorderly manner due to the dopant-aluminum nitride, the zinc oxide film 26 exhibits poor crystallinity and oxygen deficiency. The system 30 for activating the zinc oxide thin film may employ a laser generator 31 having a wavelength of 355 nm (or a different wavelength may also be used) to activate the zinc oxide thin film 26 doped with aluminum nitride, and the laser light of the laser generator 31 is expanded. The expander 32 and the mirror 33 change the beam size and direction, and use a homogenizer 34 and a focusing lens 35 to shape the laser beam having a Gaussian distribution into a flat-topped beam, and The homogenized laser light is projected onto a substrate 24 having a zinc oxide film 26. The energy uniform laser flat-top beam can uniformly activate the zinc oxide film 26 doped with aluminum nitride, and the activated aluminum nitride and nitrogen fill the oxygen deficiency of the zinc oxide.

After activation, the zinc oxide film 26 of aluminum nitride has internal lattice reforming and dopant positioning. FIG. 4A shows the intensity distribution pattern of the X-ray diffraction (XRD) analysis of the zinc oxide film before and after the laser activation treatment, and is activated. The treated zinc oxide film is improved in crystallinity due to lattice reforming, that is, the zinc oxide crystal after activation has a large increase in the strength of the C-axis (ZnO (002)). In addition, FIG. 4B shows the measurement results of the light transmittance of the zinc oxide film before and after the laser activation treatment, and the transmittance of the activated zinc oxide film is remarkably improved by about 10% in the visible light band.

The activation result of the aluminum nitride-doped zinc oxide film 26 can be changed by adjusting the power and number of lasers, thereby controlling the carrier type (N-type or P-type) and carrier concentration of the electrical characteristics. Table 1 shows the various properties of the zinc oxide film doped with aluminum nitride by different laser parameters. When the laser power is 0.2W and the number of hair is 100 rounds, the zinc oxide film doped with aluminum nitride after activation has a P-type, and the carrier concentration is about 1.04×10 ¹⁶ /cm ^{3 .} . When the number of laser shots was increased to 200 rounds, the hole concentration of the zinc oxide film was increased to 3.67 × 10 ¹⁷ /cm ³ . In addition, when the laser power is 0.15W and the number of hair is 100 rounds, the zinc oxide film doped with aluminum nitride after activation has a similar type I type with a high resistance value (about 1757.167 Ω-cm). The carrier concentration was about 1.37 × 10 ¹⁵ /cm ³ . When the laser power is increased above 0.25W and the number of shots is also 100 rounds, the zinc oxide film doped with aluminum nitride after activation has an N-type carrier type, and the carrier concentration of the zinc oxide film is greater than 2.66. ×10 ¹⁸ /cm ³ . Therefore, the power and number of lasers can be adjusted to change the carrier type (type I, N or P type) and carrier concentration of the zinc oxide film 26 doped with aluminum nitride.

Table 1: Various characteristics of activated zinc oxide film doped with aluminum nitride with different laser parameters

The difference between before and after activation of the zinc oxide film doped with aluminum nitride was analyzed by low-temperature photoluminescence (PL) spectrum. A ⁰ X signal appeared at 3.342 eV in the spectrum of Fig. 5, which represents the aluminum nitride after doping activation. N in the middle will fill the oxygen deficiency of zinc oxide, thus forming a hole. The oxygen vacancy in the formed P-type zinc oxide film is also significantly inhibited, so that a more stable P-type zinc oxide film is formed after the activation of the dopant, and the decrease of the oxygen vacancy concentration in the film is a key factor. In addition, when the laser power in Table 1 above is increased to 0.25 W, the zinc oxide film after activation treatment changes its carrier type to the N type. If the laser power continues to increase, the electron concentration also increases slightly. The reason is that when the laser activation energy is too high, the oxygen atoms in the zinc oxide film diffuse outward to form oxygen vacancies, which increases the electron concentration.

6A to 6F are semiconductor elements in which zinc oxide thin films having different carrier types or carrier concentrations are formed on a substrate by adjusting parameters of laser activation. 6A is a zinc oxide film doped with aluminum nitride by a common sputtering method on a substrate 61, and then adjusting the laser light to a suitable power and number of rays to irradiate the entire area of the zinc oxide film to form a film. A whole layer of P-type zinc oxide film 62. Another zinc oxide film doped with aluminum nitride is formed on the P-type zinc oxide film 62 in the same manner, and irradiated with different laser light powers and hair waves to form an entire layer of N-type zinc oxide film 63. As shown in Figure 6B. The P-type zinc oxide film 62 and the N-type zinc oxide film 63 are stacked on top of each other to form a semiconductor element having a PN junction. These semiconductor structures can be applied to light emitting diodes, photovoltaic elements, and solar cells.

FIG. 6C adjusts the laser light to an array parameter such as a suitable power and the number of shots, and sequentially irradiates the unactivated zinc oxide film 62c to form a P-type zinc oxide region 631 and an N-type zinc oxide region 632. Similarly, by changing the carrier concentration of the local region of the unactivated zinc oxide film 62d by a suitable laser light irradiation parameter, an adjacent P-type zinc oxide region 641, a type I zinc oxide region 642, and an N-type zinc oxide region 643 may be formed. That is, the PIN element is obtained, as shown in Fig. 6D. Or by using a suitable laser light irradiation parameter to change the carrier concentration of the local region of the unactivated zinc oxide film 62e, an adjacent P-type zinc oxide region 651, an N-type zinc oxide region 652, and a P-type zinc oxide region 653 may be formed. That is, a PNP element is obtained, as shown in Fig. 6E. To obtain the NPN element, an adjacent N-type zinc oxide region 661, a P-type zinc oxide region 662, and an N-type zinc oxide region 663 can be formed on the unactivated zinc oxide film 62f as shown in FIG. 6F.

The use of this technology to directly form a transparent semiconductor device pattern on the zinc oxide film can reduce the use of the mask and the etching process, and further simplify the process of the semiconductor device to reduce the cost and shorten the processing time.

The technical content and technical features of the present disclosure have been disclosed as above, and those skilled in the art can still make various substitutions and modifications without departing from the spirit and scope of the disclosure. Therefore, the scope of the present disclosure is not to be construed as being limited by the scope of

11. . . Substrate

12. . . N-type zinc oxide layer

13. . . Zn ₃ P ₂ film

20. . . Sputtering system

twenty one. . . Vacuum chamber

22, 23. . . Sputter source

twenty four. . . Substrate

25. . . Clamping seat

26. . . Zinc oxide film doped with aluminum nitride

30. . . System for activating zinc oxide film

31. . . Laser generator

32. . . Expander

33. . . Reflector

34. . . Uniformizer

35. . . Focusing lens

61. . . Substrate

62. . . P-type zinc oxide film

63. . . N-type zinc oxide film

62c~62f. . . Unactivated zinc oxide film

221. . . Aluminum nitride target

231. . . Zinc oxide target

631, 641, 651, 653, 662. . . P-type zinc oxide region

632, 643, 652, 661, 663. . . N-type zinc oxide region

642. . . Type I zinc oxide region

Figure 1 is a schematic view showing the formation of a P-type zinc oxide film layer in U.S. Patent No. 6,624,442;

2 illustrates a sputtering system for forming a zinc oxide film according to an embodiment of the present invention;

3 illustrates a system for activating a zinc oxide film according to an embodiment of the present invention;

4A is a graph showing the intensity distribution pattern of the X-ray diffraction analysis of the zinc oxide film before and after the laser activation treatment;

4B shows the measurement results of the light transmittance of the zinc oxide film before and after the laser activation treatment;

Figure 5 shows the low-temperature photoluminescence (PL) spectrum analysis before and after the activation of the zinc oxide film doped with aluminum nitride Spectrogram; and

6A to 6F are semiconductor elements in which zinc oxide thin films having different carrier types or carrier concentrations are formed on a substrate by adjusting parameters of laser activation.

61. . . Substrate

62e. . . Unactivated zinc oxide film

651. . . P-type zinc oxide region

652. . . N-type zinc oxide region

653. . . P-type zinc oxide region

Claims (22)

A semiconductor device having a zinc oxide film, comprising: a substrate; and a dopant-containing zinc oxide film disposed on the substrate, wherein a portion of the zinc oxide film comprises at least two different carrier types The area. A semiconductor element having a zinc oxide thin film according to claim 1, wherein the dopant is aluminum nitride (AlN), gallium nitride (GaN) or indium nitride (InN). A semiconductor device having a zinc oxide thin film according to claim 1, wherein the dopant is lithium (Li), sodium (Na), potassium (K), gold (Au), silver (Ag) or copper (Cu). . A semiconductor element having a zinc oxide thin film according to claim 1, wherein the dopant is lithium nitride (LiN), silver nitride (NAg), phosphorus nitride (NP) or magnesium nitride (MgN). The semiconductor device having a zinc oxide thin film according to claim 1, wherein the carrier types of the two regions are respectively two of the N-type, the P-type, and the I-type. A semiconductor device having a zinc oxide thin film according to claim 1, wherein the carrier patterns of the two regions are respectively an N-type and a P-type, and the two regions form a PN junction. The semiconductor device having a zinc oxide thin film according to claim 6, further comprising a P-type carrier type region, the three regions forming a PNP junction element. The semiconductor device having a zinc oxide thin film according to claim 6, further comprising an N-type carrier type region, the three regions forming an NPN junction element. The semiconductor device having a zinc oxide thin film according to claim 1, wherein the carrier patterns of the two regions are respectively an N-type and a P-type, and further comprising an I in the middle of the two regions. A region of the type of carrier that forms a component of a PIN junction. A semiconductor element having a zinc oxide thin film according to claim 1, wherein the activation treatment changes the carrier type and the carrier concentration by irradiating the partial area with laser light. A semiconductor device having a zinc oxide thin film, comprising: a substrate; and a dopant-containing zinc oxide film disposed on the substrate and partially including at least one activated dopant region. A semiconductor element having a zinc oxide thin film according to claim 11, wherein the dopant is aluminum nitride (AlN), gallium nitride (GaN) or indium nitride (InN). A semiconductor element having a zinc oxide thin film according to claim 11, wherein the dopant is lithium (Li), sodium (Na), potassium (K), gold (Au), silver (Ag) or copper (Cu). . A semiconductor element having a zinc oxide thin film according to claim 11, wherein the dopant is lithium nitride (LiN), silver nitride (NAg), phosphorus nitride (NP) or magnesium nitride (MgN). A semiconductor element having a zinc oxide thin film according to claim 11, wherein the region of the activated dopant is in an N-type, P-type or I-type. A semiconductor device having a zinc oxide thin film according to claim 11, wherein the region of the activated dopant is an N-type region, and further includes a region having a P-type carrier type, the two regions forming a PN The components of the junction. A semiconductor element having a zinc oxide thin film according to claim 11, wherein The region of the activated dopant is an N-type, and further comprises a region of a P-type carrier type, the two regions forming a component of a PN junction. The semiconductor device having a zinc oxide thin film according to claim 17, further comprising a P-type carrier type region, the three regions forming a PNP junction element. A semiconductor device having a zinc oxide thin film according to claim 17, further comprising a region having an N-type carrier type, the three regions forming an NPN junction element. The semiconductor device having a zinc oxide thin film according to claim 11, wherein the region of the activated dopant is an N-type region, and further comprises two regions each having an I-type and a P-type carrier type, the two The area forms a component of a PIN junction. A semiconductor device having a zinc oxide thin film according to claim 11, wherein the region is a partial area of the dopant-containing zinc oxide film subjected to activation treatment. A semiconductor element having a zinc oxide thin film according to claim 21, wherein the activation treatment changes the carrier type and the carrier concentration by irradiating the partial area with laser light.