JP2006135208A - Method for manufacturing diffusion region of rare earth element ion, light-emitting diode, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable control of the desired position of the concentration distribution peak values of rare earth element ions and adjustment of the luminous intensity of a light-emitting element, by keeping the rare earth element ions in a predetermined distribution conditions and moving the diffusion region of rare earth element ions in a substrate depthwise direction through heat treatment. <P>SOLUTION: A manufacturing method comprises the steps of forming a diffusion region 16 of rare earth element ions, having a predetermined distribution in a substrate 11, and keeping rare earth element ions in a state of predetermined distribution and making the diffusion region 16 of rare earth element ions move, in the depthwise direction of the substrate 11 through heat treatment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention can be applied to a method for producing a rare earth element diffusion region and a light emitting device such as a display or a backlight. The light emitting layer includes a semiconductor two-dimensional quantum well structure, a semiconductor quantum wire, or a semiconductor quantum dot. The present invention relates to a method for manufacturing a light-emitting element containing rare earth element ions and the light-emitting element.

  Currently, many light emitting devices such as light emitting diodes and semiconductor lasers are mainly made of III-V or II-VI group compound semiconductor materials such as GaAs. However, the production of these compound semiconductor materials requires an expensive substrate such as a sapphire substrate, the production process is difficult due to the use of dangerous and harmful gases such as arsine, There are problems such as the need for large and expensive manufacturing equipment such as equipment and high running costs.

  On the other hand, many semiconductor devices such as transistors and memory devices are currently made using silicon or silicon compound materials. This is because silicon resources are abundant and inexpensive, and the environmental load is small. In particular, the high integration of LSIs in silicon materials has been steadily advancing through the miniaturization of individual transistors for a long period of about 30 years since the 1970s, and DRAMs with gigabit-level integration are on the market. Even now, it continues to be developed to further improve the performance of integrated circuits in the future. In this way, silicon and silicon compounds, which are excellent semiconductor device materials that have accumulated know-how in miniaturization technology, are low in raw material costs, and have a low environmental impact, are indirect transition types. However, it has not been studied so far as a light emitting device.

  Under such circumstances, various studies and proposals have been reported for efficiently converting carriers into light in the indirect transition type silicon material as in the direct transition type (for example, patent documents). 1, 2, 3). One method is to localize the carrier wave function and use the quantum effect. According to this method, by using quantum wells such as a two-dimensional quantum well structure, a one-dimensional quantum well structure (quantum wire), and a zero-dimensional quantum well structure (quantum dots), electrons and holes that are carriers are small. Can be trapped in a size container. For quantum dots, in particular, by localizing electrons and holes in the 0th dimension, the density of states of carriers can be approximated by a delta function, and the wave function of carriers according to the size of carrier confinement can be quantized. Occurs and the energy takes discrete values. By controlling the confinement method and the size, it is possible to improve the efficiency of band edge luminescence recombination.

  Conventionally, it is known that atoms of rare earth elements added to semiconductors exhibit sharp infrared and visible emission due to intrashell transition. It is known that the emission wavelength and the half-value width of such rare earth element atoms show a constant value almost independent of the base material made of a semiconductor or the temperature. In particular, among the rare earth elements, erbium (Er) emits light at a wavelength of 1.55 μm. Since the 1.55 μm emission wavelength is the minimum transmission loss wavelength of an optical fiber, application to optical fiber communication by erbium emission is expected (see, for example, Patent Document 2).

  As described above, research on light emitting materials such as semiconductor quantum dots and rare earth elements has been reported, but research and proposals on device structures for effectively functioning as light emitting devices have been sufficiently conducted. There is no current situation.

It is known that the emission wavelength obtained only with nanocrystals usually shows a large half-value width of several tens to several hundreds of nanometers. The emission wavelength with this wide half-value width is narrow and the emission intensity is small. At present, it is considered difficult to improve the emission wavelength. In addition, research has been conducted to form and add rare earth elements such as erbium (Er) into a material having a large band gap such as silicon oxide (SiO ₂ ), and to emit light by photoexcitation or electron beam excitation. When light is emitted by current injection as an electronic device, a current is passed through silicon oxide (SiO ₂ ) that is an insulator. In this case, since the electric resistance of silicon oxide (SiO ₂ ) is large, almost no current flows and it is difficult to obtain sufficient light emission intensity.

Therefore, for example, by using a silicon oxide (SiO ₂ ) film containing quantum wells and rare earth element ions as a light emitting layer, a light emitting element in which rare earth element ions are simply dispersed in a silicon oxide film that is an insulator. In comparison, a light-emitting element that can flow a large current at a lower voltage, has a narrow half-value emission wavelength, and can increase the emission intensity has been studied. This is thought to be because carriers are trapped in the semiconductor quantum well formed in the silicon oxide film, which is an insulator, and the energy of the carriers is confined. At this time, the rare earth element is located in the vicinity of the semiconductor quantum well. When ions are present, it is considered that the energy of carriers confined in the semiconductor quantum well is transferred to the rare earth element ions, and light emission occurs due to the transition in the shell of the rare earth element ions. In this case, there is no semiconductor quantum well, and it is expected that a stronger emission intensity can be obtained as compared with the case where light emission is caused by the transition of rare earth element ions only by hot electrons.

  Furthermore, in the configuration including the semiconductor quantum well structure, the electrical resistance of the light emitting layer is reduced and the voltage of the light emitting element can be reduced as compared with the light emitting layer made of only silicon oxide as an insulator. Further, when eurobium (Eu) or praseodymium (Pr) is used as a rare earth element ion, a red light emitting element is obtained. When erbium (Er) is used as a rare earth element, an orange light emitting element is obtained, and terbium (Tb) or cerium (Ce) is used as a rare earth element. When green is used, a green light emitting element is obtained, and when cerium (Ce) or thulium (Tm) is used as the rare earth element, a blue light emitting element is obtained.

The components constituting the light emitting layer other than the rare earth element ions are produced by annealing a SiO _2−x (2 ≧ x ≧ 0) film produced by a chemical vapor deposition method or a sputtering method. Further, the rare earth element ions may be directly produced in the light emitting layer by an ion implantation method. The light emission intensity changes according to the distance from the center position of the distribution of rare earth element ions in the light emitting layer of the light emitting element to the quantum well.

Japanese Patent Laid-Open No. 9-295891 JP 2002-536850 A JP 2001-203382 A

  The problem to be solved is that rare earth ions introduced into the light emitting layer are introduced by an ion implantation method, but the position of the peak value in the concentration distribution of the rare earth element ions in the light emitting layer is determined during the ion implantation. It depends on the acceleration energy. For this reason, as the position of the peak value is farther from the surface of the light emitting layer (deeper), larger acceleration energy and time are required. Furthermore, when the ion implantation process is outsourced, the cost increases with time. In addition, when manufacturing several light emitting elements that differ only in the position of the peak value in the concentration distribution of rare earth element ions, it is necessary to perform ion implantation separately depending on the position of the different peak value. In addition, there is a problem that time and cost increase.

  The method of manufacturing a rare earth element ion diffusion region according to the present invention includes a step of forming a rare earth element ion diffusion region having a predetermined distribution in a substrate, and the distribution of the rare earth element ion to a predetermined distribution state by heat treatment. And a step of moving the diffusion region of the rare earth element ions in the depth direction of the substrate.

  A method for manufacturing a light emitting device according to the present invention is a method for manufacturing a light emitting device in which a light emitting layer formed on a substrate includes a quantum well and a rare earth element ion, and the light emitting layer is in contact with the quantum well. After introducing the rare earth element ions into the material layer, the distribution state of the rare earth element ions introduced into the material layer constituting the light emitting layer is maintained in a predetermined distribution state, and the rare earth element is arranged in the depth direction of the substrate. The main feature is to perform heat treatment to move the diffusion region of element ions.

  A light emitting device according to the present invention is a light emitting device including a quantum well and a rare earth element ion in a light emitting layer formed on a substrate, and the distribution state of the rare earth element ion is changed to a predetermined distribution state by heat treatment. The main feature is that the diffusion region of the rare earth element ions moves in the depth direction of the substrate.

  The method for producing a rare earth element ion diffusion region according to the present invention moves the rare earth element ion diffusion region in the depth direction of the substrate while maintaining the distribution state of the rare earth element ion in a predetermined distribution state by heat treatment. There is an advantage that the distribution state of the diffusion region of the element ions can be maintained, the concentration peak position (position where the concentration is highest) of the diffusion region of the rare earth element ions can be easily adjusted, and the cost can be reduced.

  The method for manufacturing a light-emitting element according to the present invention maintains a distribution state of rare-earth element ions introduced into a material layer constituting a light-emitting layer in a predetermined distribution state, and provides a diffusion region of rare-earth element ions in the depth direction of the substrate. Since the heat treatment to be performed is performed, the concentration peak position of the rare earth element ion diffusion region can be moved while maintaining the distribution state of the diffusion region, so that a desired position can be easily adjusted. As a result, the peak position of the concentration distribution in the rare earth element ion diffusion region in the light emitting layer can be adjusted, so that the light emission intensity of the light emitting element can be adjusted by heat treatment. In addition, there is an advantage that it can be made inexpensive.

  Since the light emitting device according to the present invention is a light emitting device manufactured by the method for manufacturing a light emitting device of the present invention, the position of the peak value of the concentration distribution in the rare earth ion diffusion region is formed at a desired position. There is an advantage that a light emitting element having a desired light emission intensity is obtained.

  The purpose of controlling the peak position of the concentration distribution of the rare earth element ions to adjust the emission intensity of the light emitting element is to perform a heat treatment, thereby maintaining the distribution state of the rare earth element ions in a predetermined distribution state and the depth of the substrate. Realized by moving the diffusion region of rare earth ions in the direction.

  First, the manufacturing method of the rare earth element ion diffusion region of the present invention will be described with reference to the manufacturing process sectional view of FIG.

  As shown in FIG. 1A, a first material layer 12 mainly composed of silicon and a quantum well 13 are formed on the substrate 11 by plasma enhanced chemical vapor deposition (PE-CVD). A second material layer 14 mainly composed of silicon is formed. Rare earth element ions are implanted into the second material layer 14 to form a rare earth element ion diffusion region 16. In FIG. 1, the second material layer 14 and the diffusion region 16 are drawn enlarged in the thickness direction for easy understanding of the drawing.

  Next, as shown in FIG. 1 (2), the diffusion region 16 is moved in the depth direction in the second material layer 14 while maintaining the distribution state of the rare earth element ions in a predetermined distribution state by heat treatment. At this time, the distribution state of the rare earth element ions in the diffusion region 16 is wider than that during ion implantation, but the distribution state of the rare earth element ions in the diffusion region 16 hardly changes depending on the heat treatment conditions.

  Therefore, according to the method for producing a rare earth element ion diffusion region of the present invention, ion implantation conditions are determined so that a desired rare earth element ion distribution state is obtained, and then ion implantation of rare earth element ions is performed. By performing the heat treatment, the position of the concentration distribution peak value (the highest concentration value) of the rare earth element ions 15 in the diffusion region 16 can be moved to a desired position.

  Next, an example of a light-emitting element to which the method for manufacturing a light-emitting element of the present invention can be applied will be described with reference to a schematic cross-sectional view of FIG.

As shown in FIG. 2, a silicon substrate is used as the substrate 11 on which the light emitting element 1 is formed. A first material layer 12 mainly composed of silicon is formed on the substrate 11. The first material layer 12 is formed of, for example, a silicon oxide (SiO ₂ ) layer. A quantum well 13 is formed on the first material layer 12. The quantum well here refers to a two-dimensional quantum well (common name: quantum well), a one-dimensional quantum well (common name: quantum wire), and a zero-dimensional quantum well (common name: quantum dot). Hereinafter, in this specification, quantum wells are defined as described above. The quantum well 13 is made of, for example, silicon, germanium, or silicon germanium. Alternatively, the quantum well 13 is made of a silicon-based oxide. A second material layer 14 mainly composed of silicon is formed on the quantum well 13. The second material layer 14 is formed of, for example, a silicon oxide (SiO ₂ ) layer. Furthermore, rare earth element ions 15 are introduced into the second material layer 14 in the vicinity of the quantum well 13 to form a rare earth element ion diffusion region 16. The diffusion region 16 is formed so that the concentration distribution peak value of the rare earth element ions 15 in the diffusion region 16 is located within a range of 10 nm from the quantum well 13. In this way, by introducing the rare earth element ions 15, it becomes possible to cause energy transfer by the Forster mechanism or the Dexter mechanism. In other words, the concentration peak value is located within the range where the energy transition by the Forster mechanism or the Dexter mechanism occurs from the quantum well 13. The Forster mechanism is energy transfer due to resonance dipole-dipole interaction, and the Dexter mechanism is energy transfer due to exchange of electrons due to intermolecular contact. In addition, the concentration peak value is positioned within a range where energy transition from the quantum well 13 via the photon occurs.

  Next, an example of the method for manufacturing the light emitting element 1 will be described with reference to the manufacturing process sectional view of FIG. In FIG. 3, the second material layer 14 and the diffusion region 16 are drawn enlarged in the thickness direction for easy understanding of the drawing.

As shown in FIG. 3A, a silicon substrate is prepared as the substrate 11. Next, the first material layer 12 mainly composed of silicon is formed on the substrate 11 by plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition = PE-CVD). The first material layer 12 is formed, for example, by forming a silicon oxide (SiO ₂ ) film to a thickness of about 100 nm.

  Next, the quantum well 13 is formed on the first material layer 12 by, for example, PE-CVD. The quantum well 13 can be formed of, for example, a silicon layer, a germanium layer, or a silicon germanium layer. Alternatively, it can be formed of a silicon-based oxide layer. Here, as an example, the quantum well 13 is formed by forming a silicon layer with a thickness of 10 nm.

Further, a second material layer 14 mainly composed of silicon is formed on the quantum well 13 by PE-CVD. The second material layer 14 is formed, for example, by forming a silicon oxide (SiO ₂ ) film to a thickness of about 70 nm.

  Next, as shown in FIG. 3B, rare earth element ions 15 are implanted from the surface of the second material layer 14 by ion implantation. For example, the concentration distribution peak value of the rare earth element ions 15 is positioned at a depth of 35 nm from the surface of the second material layer 14, that is, a depth of, for example, about 35 nm from the surface of the quantum well 13 to the second material layer 14 side. Rare earth element ions 15 are ion-implanted so as to be in this position. Here, as an example, terbium ions are used as rare earth element ions in order to obtain green light emission. Further, in order to obtain other emission colors, the other rare earth element ions described above can be implanted.

Specifically, terbium ions as rare earth element ions are implanted into the second material layer 14 with an acceleration energy of about 50 keV and a dose of about 1 × 10 ¹⁴ atoms / cm ² .

In this way, the first material layer 12 made of SiO ₂ film is formed on the substrate 11 to a thickness of 100 nm, and the quantum well 13 made of silicon (Si) layer is formed on the first material layer 12. The second material layer 14 made of SiO ₂ film is formed on the quantum well 13 with a film thickness of 70 nm, and the concentration of the rare earth element ion (terbium ion) diffusion region 16 introduced into the second material layer 14. The light emitting element 1 in which the position of the distribution peak value was formed at a position about 35 nm away from the quantum well 13 was obtained.

  The light-emitting element 1 emits red light when eurobium (Eu) is used as the rare earth element. When praseodymium (Pr) is used, red light is emitted. When erbium (Er) is used, it emits orange light. When terbium (Tb) is used, green light is emitted. When cerium (Ce) is used, blue light is emitted. When thulium (Tm) is used, blue light is emitted. In addition, as the rare earth element, plural kinds of rare earth elements can be used. The emission color in this case is, for example, a mixture of specific emission colors emitted by the rare earth element ions introduced into the light emitting element 1.

  Next, a first embodiment according to the method for manufacturing a light emitting device of the present invention will be described. The light-emitting element 2 of the first example is the same as the light-emitting element 1 manufactured by the manufacturing method described with reference to FIG. 3 in an inert atmosphere with the surface of the light-emitting layer facing upward at 1100 ° C. for 30 minutes. , Produced by annealing. As a result, as shown in FIG. 4, the diffusion region 16 of the rare earth element ions moved in the second material layer 14 while maintaining a predetermined distribution state of the rare earth element ions in the direction of the quantum well layer 13.

  Next, a second embodiment according to the method for manufacturing a light emitting device of the present invention will be described. The light emitting device 3 of the second embodiment is the same as the light emitting device 1 manufactured by the manufacturing method described with reference to FIG. 3 in an inert atmosphere at 1200 ° C. for 30 minutes with the surface of the light emitting layer facing upward. , Produced by annealing. As a result, as shown in FIG. 5, the rare earth element diffusion region 16 maintains a predetermined rare earth element ion distribution state in the second material layer 14 in the direction of the quantum well layer 13, and further than the light emitting element 2. moved.

  Next, a third embodiment according to the method for manufacturing a light emitting device of the present invention will be described. The light-emitting element 4 of the third example is the same as the light-emitting element 1 manufactured by the manufacturing method described with reference to FIG. 3 in an inert atmosphere with the surface of the light-emitting layer facing downward at 1200 ° C. for 30 minutes. , Produced by annealing. As a result, as shown in FIG. 6, the rare earth element ion diffusion region 16 moved in the second material layer 14 while maintaining a predetermined rare earth element ion distribution state in a direction opposite to the quantum well layer 13 direction.

  The distribution state of rare earth element ions (terbium ions) in the second material layer 14 constituting the light emitting layer of each of the light emitting elements 1 to 4 was examined by Ratherford backscattering (RBS) measurement.

  Table 1 shows the ion distribution measurement results of the light-emitting elements 1 to 4.

  As shown in Table 1, in the light-emitting element 1, the distance from the quantum well 13 to the position of the concentration distribution peak value of the rare earth element ion (terbium ion) was 35 nm. The standard deviation indicating variation in the distribution of the terbium ions was 17 nm.

  Further, in the light-emitting element 2 of Example 1 in which the light-emitting element 1 is used and an additional annealing treatment is performed at 1100 ° C. for 30 minutes in an inert atmosphere with the light-emitting surface facing upward, the quantum well 13 The distance from the position of the concentration distribution peak value of rare earth element ions (terbium ions) to 10 nm was 10 nm. The standard deviation indicating variation in the distribution of the terbium ions was 23 nm. As described above, the position of the concentration distribution peak value of the rare earth element ion (terbium ion) is within the range where the energy transition is caused by the Forster mechanism. Moreover, it is also in the range where energy transition through photons occurs.

  Further, in the light-emitting element 3 of Example 2 in which the light-emitting element 1 is used and an additional annealing treatment is performed at 1200 ° C. for 30 minutes in an inert atmosphere with the light-emitting surface facing upward, the quantum well 13 The distance from the position of the terbium ion (terbium ion) concentration distribution peak value was 5 nm. The standard deviation indicating variation in the distribution of the terbium ions was 24 nm. As described above, the position of the concentration distribution peak value of the rare earth element ion (terbium ion) is within the range where the energy transition is caused by the Forster mechanism. Moreover, it is also in the range where energy transition through photons occurs.

  Further, in the light-emitting element 4 of Example 3 in which the light-emitting element 1 is used and the light-emitting surface thereof is directed downward and an additional annealing treatment is performed at 1200 ° C. for 30 minutes in an inert atmosphere, the quantum well 13 The distance from the position of the concentration distribution peak value of terbium ions (terbium ions) to 60 nm was 60 nm. The standard deviation indicating variation in the terbium ion concentration distribution was 23 nm.

  In this way, by performing a heat treatment on the rare earth element ions (for example, terbium ions) introduced into the material layer so as to have a predetermined distribution, the concentration distribution state of the rare earth element ions in the material layer is maintained, The position of the concentration distribution peak value of the rare earth element ions can be freely changed.

  In the light-emitting elements 1 to 4, terbium ions are used as the rare earth element ions, but similar results can be obtained with other rare earth element ions.

  Next, the optical characteristics of each of the light emitting elements 1 to 4 were evaluated. The optical property evaluation method will be described.

  The optical characteristics of the light-emitting elements 1 to 4 were evaluated in a room temperature environment using a photoluminescence (PL) measuring device (excitation light: HeCd laser / excitation power: 30 mW / detector: silicon photo detector). Specifically, light emitted from each light-emitting element irradiated with a HeCd laser (excitation power: 30 mW) was received by a silicon photodetector, and the emission intensity of light having an emission peak near 545 nm was read.

  The results of the optical characteristics are shown in Table 2. The light emission intensity in Table 2 is the light emission intensity when the light emission intensity of the light emitting element 1 is 100.

  As shown in Table 2 above, when the light emission intensity of the light emitting element 1 is 100, the light emission intensity of the light emitting element 2 is 150, the light emission intensity of the light emitting element 3 is 180, and the light emission intensity of the light emitting element 4 is 40. It was.

  Thus, in the case where the distance from the quantum well 13 to the position of the concentration distribution peak value of the terbium ions is 10 nm (light emitting element 2) and 5 nm (light emitting element 3), for example, a resonant dipole-dipole mutual relationship It is said that the upper limit of the moving distance by the energy transfer by action (Forster mechanism) is 10 nm, and since it is within 10 nm, the energy transition efficiency is greatly improved.

  Further, by devising the additional heat treatment condition, the distance from the quantum well 13 to the position of the concentration distribution peak value of terbium ions can be set to 1 nm. In this case, for example, the upper limit of the movement distance by energy transfer (exchange mechanism or Dexter mechanism) due to exchange of electrons by intermolecular contact is said to be 1 nm, and this energy is within 1 nm. It is expected that the transition efficiency will be further improved.

As described above, as the light emitting layer, the quantum well 13 made of a semiconductor material mainly containing Si or (SiO _2−x (2>x> 0)) and rare earth element ions (for example, terbium ions) are used. In the light emitting element using the second material layer 14 made of silicon oxide, the concentration distribution peak value of rare earth element ions (for example, terbium ions) in the light emitting layer is moved by heat treatment in an inert atmosphere. The position of the distribution center can be adjusted according to the heat treatment conditions.

  Furthermore, since the emission intensity changes according to the distance between the position of the concentration distribution peak value of rare earth element ions (for example, terbium ions) and the quantum well 13, the concentration distribution peak value of rare earth element ions (for example, terbium ions) The position of the peak value can be adjusted by moving the position. Thereby, the light emission intensity of the light emitting element can be adjusted.

  In addition, the standard deviation of the distribution of rare earth element ions (for example, terbium ions) in the heat-treated light-emitting element tends to be larger than the concentration distribution just by ion implantation, and the concentration of rare earth element ions (for example, terbium ions). The distribution tends to expand. However, since there is almost no difference in the standard deviation of rare earth element ions (for example, terbium ions) due to this heat treatment condition, it can be seen that the distribution state of rare earth element ions (for example, terbium ions) hardly changes. That is, in this heat treatment, the position of the concentration distribution peak value of the rare earth element ions can be set while maintaining a predetermined distribution state of the rare earth element ions.

  In the light-emitting elements 1 to 4, the case where the film thickness of the first material layer 12 is 100 nm is described, and the case where the film thickness of the second material layer 14 is 70 nm is described. The same effect can be obtained. Moreover, even if the film thickness of the 1st, 2nd material layers 12 and 14 is the same, the same effect is acquired.

  In the light-emitting elements 1 to 4, the case where the quantum well 13 has a thickness of 10 nm has been described. However, the same effect can be obtained even with the quantum well 13 having other thicknesses.

In the light emitting elements 1 to 4, silicon (Si) has been described as the material of the quantum well 13, but any material having a function as a quantum well may be used. For example, silicon oxide (SiO _2-x (2 >X> 0)) as a main component, silicon-based compounds such as silicon nitride or a mixture thereof including silicon as a main component, silicon group-based materials such as germanium (Ge) or a mixture thereof, other semiconductor materials or Even if the mixture is used, the same effect can be obtained.

In the light-emitting elements 1 to 4, the case where the quantum well 13 is arranged so as to be parallel to the surface of the substrate 11 has been described. However, the quantum well is made of SiO ₂ formed on the substrate 11. The same effect can be obtained even when the second material layer 14 is randomly arranged. For example, it may be composed of quantum dots, quantum wires or the like.

  In the light-emitting elements 1 to 4, the case where a silicon substrate is used as the substrate 11 has been described. However, the substrate 11 may be another semiconductor substrate, an SOI substrate, a compound semiconductor substrate, or the like.

  In the light-emitting elements 1 to 4, terbium ions are described as rare earth element ions, and further, it has been described that rare earth element ions such as eurobium, praseodymium, erbium, cerium, and thulium can be used. Similar effects can be expected for elemental ions.

  In the light emitting elements 1 to 4, an argon atmosphere can be used as an inert atmosphere. In addition, for example, a similar effect is expected even when a rare gas atmosphere other than argon, a nitrogen atmosphere, or a vacuum atmosphere is used. it can. Here, the vacuum is not a physical vacuum but an industrial vacuum that can be achieved by using a vacuum pump or the like.

  In the method of manufacturing a rare earth element ion diffusion region according to the present invention, the rare earth element ion diffusion region 16 is moved in the depth direction of the substrate 11 while the distribution state of the rare earth element ions 15 is maintained in a predetermined distribution state by heat treatment. Therefore, since the position of the concentration distribution peak value of the rare earth element ions can be moved while maintaining the distribution state of the diffusion region 16, the position of the concentration distribution peak value of the rare earth element ions can be easily adjusted and can be made inexpensive. There is an advantage.

  In the method for manufacturing a light emitting device according to the present invention, the distribution state of the rare earth element ions 15 introduced into the second material layer 14 constituting the light emitting layer is maintained in a predetermined distribution state, and the diffusion region is formed in the depth direction of the substrate 11. Since the heat treatment for moving 16 is performed, the position of the concentration distribution peak value of the rare earth element ions 15 in the diffusion region 16 can be moved while maintaining the distribution state of the rare earth element ions 15, so that the position of the concentration distribution peak value can be easily set. Can be combined. Thereby, the position of the concentration distribution peak value of the rare earth element ions 15 in the diffusion region 16 in the light emitting layer can be adjusted, so that the light emission intensity of the light emitting element 1 can be adjusted by the heat treatment. In addition, there is an advantage that it can be made inexpensive.

  Since the light-emitting element 1 according to the present invention is a light-emitting element manufactured by the method for manufacturing a light-emitting element according to the present invention, the position of the concentration distribution peak value of the rare earth element ions 15 in the diffusion region 16 is formed at a desired position. Thus, there is an advantage that the light emitting element 1 having a desired light emission intensity is obtained.

  More specifically, a desired dose amount is implanted at a position where the concentration distribution peak value of the rare earth element ions 15 is close (shallow) to the surface of the light emitting layer (second material layer 14), and heat treatment is performed. Thus, the position of the concentration distribution peak value of the rare earth element ions 15 can be moved to a desired position farther (deeper) from the surface. For this reason, the rare earth element ions 15 are implanted in advance (shallow) near the surface of the light emitting layer (second material layer 14), thereby reducing the acceleration energy during the ion implantation process and shortening the treatment time. It becomes possible to be on time. In addition, if the ion implantation process is outsourced, the cost can be reduced.

  Further, when producing several light emitting elements that differ only in the position of the concentration distribution peak value of the rare earth element ions 15, it is not necessary to perform an ion implantation process separately according to the position where the peak value differs, and the ion implantation process is performed simultaneously. After performing, the position of the concentration distribution peak value of the rare earth element ions 15 can be moved to a desired position by changing the heat treatment condition. Therefore, labor, time and cost required for the ion implantation process can be reduced.

  Even if ion implantation processing is performed with erroneous acceleration energy, the concentration distribution peak value of the rare earth element ions 15 can be moved to a desired position by heat treatment.

  Also, when adjusting the emission intensity (mainly, adjusting the emission intensity from the maximum value to a lower intensity), it is usually necessary to adjust the intensity by adjusting the rare earth element ion implantation amount. It is necessary to perform an ion implantation process. However, in the present invention, the emission intensity can be adjusted by adjusting the position of the concentration distribution peak value of the rare earth element ions 15 by heat treatment. Therefore, when manufacturing light emitting elements having different light emission intensities, light emitting elements having the same ion implantation amount can be used, so that the number of ion implantation processes can be reduced.

  The method for producing a light emitting device of the present invention includes a method for producing a light emitting device for use in an electroluminescence device, a method for producing a light emitting device for use in an intrinsic electroluminescence device, a method for producing a light emitting device for use in a current injection type electroluminescence device, and light excitation type light emission. It can be applied to a method for manufacturing a light-emitting element used in a device, and other methods for manufacturing a light-emitting element used in various light-emitting devices such as an electron injection type light-emitting device. The present invention can be applied to light-emitting elements used in various light-emitting devices, such as light-emitting elements used in electroluminescent devices, light-emitting elements used in current-injection electroluminescent devices, and light-emitting elements used in photoexcited light-emitting devices.

It is manufacturing process sectional drawing which showed the manufacturing method of the diffusion area | region of the rare earth element ion of this invention. It is schematic structure sectional drawing which showed an example of the light emitting element which can apply the manufacturing method of the light emitting element of this invention. 5 is a manufacturing process cross-sectional view illustrating an example of a method for manufacturing the light-emitting element 1. FIG. FIG. 6 is a manufacturing process cross-sectional view showing an example of a method for manufacturing the light emitting element 2. FIG. 6 is a manufacturing process cross-sectional view illustrating an example of a method for manufacturing the light emitting element 3. FIG. 6 is a manufacturing process cross-sectional view illustrating an example of a method for manufacturing the light emitting element 4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light emitting element, 11 ... Substrate, 13 ... Quantum well layer, 15 ... Rare earth element ion, 16 ... Diffusion area | region

Claims (35)

Forming a rare earth element diffusion region having a predetermined distribution in the substrate;
And a step of moving the diffusion region of the rare earth element ions in the depth direction of the substrate while maintaining the distribution state of the rare earth element ions in a predetermined distribution state by heat treatment. Area manufacturing method. A method for manufacturing a light emitting device comprising a quantum well and a rare earth element ion in a light emitting layer formed on a substrate,
After introducing the rare earth element ions into the material layer constituting the light emitting layer in contact with the quantum well,
Performing a heat treatment for maintaining the distribution state of the rare earth element ions introduced into the material layer constituting the light emitting layer in a predetermined distribution state and moving the diffusion region of the rare earth element ions in the depth direction of the substrate. A method for manufacturing a light-emitting element. A heat treatment for moving the diffusion region of the rare earth element ions in the depth direction of the substrate while maintaining the distribution state of the rare earth element ions introduced into the material layer constituting the light emitting layer in a predetermined distribution state,
After the heat treatment performed after the rare earth element ions are introduced into the material layer constituting the light emitting layer,
The method for manufacturing a light-emitting element according to claim 2. The method for manufacturing a light-emitting element according to claim 2, wherein the position of the concentration distribution peak value in the rare earth element ion diffusion region is set within a range where energy transition by the Forster mechanism occurs from the quantum well. The method of manufacturing a light emitting device according to claim 2, wherein the position of the concentration distribution peak value in the rare earth element ion diffusion region is within a range of 10 nm from the quantum well. The method of manufacturing a light emitting element according to claim 2, wherein the position of the concentration distribution peak value in the rare earth element ion diffusion region is within a range in which energy transition from the quantum well by a Dexter mechanism occurs. The method of manufacturing a light emitting element according to claim 2, wherein the position of the concentration distribution peak value in the rare earth element ion diffusion region is within a range of 1 nm from the quantum well. The method for manufacturing a light emitting element according to claim 2, wherein the position of the concentration distribution peak value in the rare earth element ion diffusion region is set within a range in which energy transition from the quantum well via photons occurs. The method for manufacturing a light emitting element according to claim 2, wherein the light emitting layer includes a quantum well, a rare earth element ion, and a material layer mainly composed of silicon. The method for manufacturing a light-emitting element according to claim 2, wherein the material layer containing silicon as a main component is made of a silicon-based oxide. The method for manufacturing a light-emitting element according to claim 2, wherein the rare earth element is eurobium (Eu). The method for manufacturing a light-emitting element according to claim 2, wherein the rare earth element is praseodymium (Pr). The method of manufacturing a light emitting device according to claim 2, wherein the rare earth element is erbium (Er). The method for manufacturing a light-emitting element according to claim 2, wherein the rare earth element is terbium (Tb). The method of manufacturing a light emitting element according to claim 2, wherein the rare earth element is cerium (Ce). The method of manufacturing a light emitting element according to claim 2, wherein the rare earth element is thulium (Tm). The method for manufacturing a light-emitting element according to claim 2, wherein the rare earth element includes a plurality of rare earth elements. The method for manufacturing a light-emitting element according to claim 2, wherein the heat treatment is performed in an inert atmosphere. The method for manufacturing a light-emitting element according to claim 18, wherein the inert atmosphere is an argon atmosphere. The method for manufacturing a light-emitting element according to claim 18, wherein the inert atmosphere is a nitrogen atmosphere. The method for manufacturing a light-emitting element according to claim 18, wherein the inert atmosphere is a vacuum atmosphere. The material layer constituting the light emitting layer is:
The method for manufacturing a light-emitting element according to claim 2, wherein the light-emitting element is formed by a chemical vapor deposition method or a sputtering method using a SiO _{2 -x} (2 ≧ x ≧ 0) film and then annealing. A light-emitting device comprising a quantum well and a rare earth element ion in a light-emitting layer formed on a substrate,
The light-emitting element is characterized in that the rare earth element ion diffusion region moves in the depth direction of the substrate while the rare earth element ion distribution state is maintained in a predetermined distribution state by heat treatment. 24. The light emitting device according to claim 23, wherein the light emission intensity is adjusted by moving a center position of the distribution of the rare earth element ions. The light emitting device according to claim 23, wherein the center position of the distribution of the rare earth element ions is moved by heat treatment. The light emitting device according to claim 23, wherein the rare earth element ions are introduced into the light emitting layer by an ion implantation method. The light emitting element according to claim 23, wherein the light emitting layer is composed of a quantum well, a rare earth element ion, and a material layer mainly composed of silicon. 28. The light-emitting element according to claim 27, wherein the material layer containing silicon as a main component is made of a silicon-based oxide. The light-emitting element according to claim 23, wherein the rare earth element is eurobium (Eu). The light emitting element according to claim 23, wherein the rare earth element is praseodymium (Pr). The light-emitting element according to claim 23, wherein the rare earth element is erbium (Er). The light-emitting element according to claim 23, wherein the rare earth element is terbium (Tb). The light-emitting element according to claim 23, wherein the rare earth element is cerium (Ce). The light-emitting element according to claim 23, wherein the rare earth element is thulium (Tm). 24. The light emitting device according to claim 23, wherein the rare earth element comprises a plurality of types of rare earth elements.

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