TW200832758A - GaN semiconductor light emitting element - Google Patents

Abstract

Provided is a GaN semiconductor light emitting element, which has an active layer having a quantum well structure containing In, suppresses thermal damage due to growing temperature of a semiconductor layer grown after growing the active layer, takes more In and has improved light emitting characteristics and electrical characteristics. On a sapphire substrate (1), an n-type GaN contact layer (2), an n-type AlInGaN/AlGaN superlattice layer (3), an active layer (4), a p-type AlGaN block layer (8) and a p-type GaN contact layer (5) are laminated, and an n-electrode (7) and a p-electrode (6) are arranged. The active layer (4) has a quantum well structure wherein a well layer satisfies the inequalities of AlX1InY1GaZ1N(X1+Y1+Z1=1, 0 < X1 < 1, 0 < Y1 < 1), and a barrier layer satisfies the inequalities of AlX2InY2GaZ2N(X2+Y2+Z2=1, 0 ≤ X2 < 1, 0 ≤ Y2 < 1, Y1 > Y2). The well layer and the barrier layer are formed by temperature modulation.

Description

[Technical Field] The present invention relates to a GaN-based semiconductor light-emitting device containing In in an active layer (light-emitting layer) of a quantum well structure. [Prior Art] • In the materials of semiconductor light-emitting elements such as semiconductor lasers or LEDs (light-emitting diodes), various substances are used, and in the use of In (锢) in the active layer (light-emitting layer) has been developed. Semiconductor light-emitting elements. In particular, in the blue light-emitting element of the GaN-based semiconductor, InGaN germanium is used as the crystal growth method of the semiconductor light-emitting device in the active layer, and a hydride vapor phase epitaxy (HVPE) or an organic metal is used. MOCVD, MetAl organic chemic Al vapor deposition. When crystal growth is carried out by using these methods, an η-type contact layer or an n-type cladding layer or the like is laminated on a growth substrate, and then an active layer as a light-emitting layer is grown, and then a ruthenium-type cladding layer or ρ is laminated. The Ρ-type layer such as the contact layer is formed, and finally the electrode is formed.

In the GaN-based semiconductor light-emitting device, for example, AlGaN or GaN is used for the cladding layer, and GaN or the like is used for the contact layer. When a GaN-based semiconductor light-emitting device is produced, an n-type GaN-based semiconductor layer is deposited on a growth substrate, and then an active layer is crystal grown. However, since the active layer contains InGaN and the vapor pressure of In is high, The growth temperature of the active layer must be lowered to about 650 to 800 °C. After the active layer is grown, the p-type GaN-based semiconductor layer is formed into a film, and in order to improve the crystal quality of the high-P-type GaN or p-type AlGaN, the growth temperature of the active reed is 200 to 300 ° C higher than that of the active layer. The growth temperature near i〇〇〇°C is crystal growth, and the growth time usually takes about 15 to 60 minutes. [Patent Document 1] JP-A-2004-55719 SUMMARY OF THE INVENTION [Problems to be Solved by the Invention]

However, as in the previous case above, when the p-type layer is formed on the active layer after the growth of the active layer, since the growth temperature of the p-type layer is high, the formed active layer is thermally damaged, thereby causing luminescence. The problem is clearly deteriorating. In particular, when a long-wavelength GaN-based semiconductor light-emitting device of 450 nm or more is produced, the In composition ratio of the well layer in the active layer is as high as more than 1%, but the higher the 111 composition ratio, the easier the Sub is sublimated when placed at a high temperature. Damage, resulting in extremely low luminous efficiency. If the thermal damage continues, the In separation will occur and the wafer will be blackened. When &lt;, when the composition ratio of the well layer is large, the growth temperature of the p-type layer is high, and the active layer is deteriorated, whereby the light-emitting characteristics are remarkably deteriorated. In order to increase the wavelength of the shell, it is necessary to increase the "composition rate" in the active layer. In order to make the amount of In in the active layer more, it is necessary to further lower the growth temperature. However, the temperature after the growth temperature is lowered. The formation of the n A layer 4 causes the following problems: 顺, the forward voltage increases or the leakage in the low-voltage region (below μΑ) increases, the reverse current increases, etc., resulting in a special H. Therefore, 'inability to improve the In' On the one hand, 126509.doc 200832758 is a good GaN-based semiconductor element. Patent Document 1 discloses a GaN-based semiconductor device having excellent luminous efficiency. The GaN-based semiconductor device is a light-emitting device having a wavelength of 3 nm or less. When the composition of the tongue-forming layer is very small, the luminous efficiency is improved by reducing the composition fluctuation, but when the In composition is increased to obtain long-wavelength light, the GaN-based semiconductor element is not prevented from being grown by epitaxy. The active layer is deteriorated by the heat generated in the process, and the electrical characteristics are not improved on the one hand, and the above-mentioned problem has not been proposed. In order to solve the above problems, an object of the invention is to provide a GaN-based semiconductor light-emitting device having an active layer containing a quantum well structure of In, and suppressing a semiconductor layer grown after the active layer The thermal damage caused by the growth temperature, and on the one hand, can increase the intake of In, and on the other hand, improve the luminescence characteristics or electrical characteristics. [Technical means for solving the problem] In order to achieve the above object, the invention of claim i is a GaN A semiconductor light-emitting device characterized in that it comprises a living layer having a quantum well structure. The active layer comprises AlxlInY1GazlN (Xl+Yi+zi = l, 〇&lt;Χΐ&lt;1 ' 〇&lt;Υ1&lt;1) The well layer and the AiX2inY2GaZ2N barrier layer (X2+Y2 + Z2 = l,, 0^γ2 &lt;1, γι > γ2), and the above-mentioned well layer (4) and more than 10%. Further, the invention of the eye 2 is a GaN A semiconductor light-emitting device characterized in that it comprises an active layer having a quantum well structure, and the active layer comprises AlxlInY1GazlN (Xl+Yl+Zl=l, 〇&lt;χι&lt;ι,〇&lt;γι&lt;1) 126509 .d〇c 200832758 The well layer and the Alx2lnY2GaZ2N barrier layer (Χ2+Υ2+Ζ2=1, 〇$Χ2&lt;1, 〇'Y2&lt;1 'Y1&gt;Y2), and the growth gradation of the above-mentioned well layer is different from the growth temperature of the barrier layer. The invention of claim 3 is the GaN-based semiconductor light-emitting device of claim 2, wherein the In composition of the well layer is greater than 1〇0/〇. Further, the invention of claim 4 is any one of claims 1 to 3. A semiconductor light-emitting device wherein the well layer has an A1 composition of 5% or less. The invention is the G aN semiconductor light-emitting device according to any one of claims 1 to 3, wherein the well layer has an A1 composition of 1% or less. The GaN-based semiconductor light-emitting device according to any one of claims 1 to 5, wherein at least the crystal growth surface of the active layer is formed of a nonpolar surface or a semipolar surface. [Effects of the Invention] The GaN-based semiconductor light-emitting device that emits light having a wavelength of 450 nm or more, that is, the active layer having an In composition ratio of more than 1% in the well layer, is particularly weak in heat resistance and heat resistance, and in the present invention, at least Since AlInGaN to which A1 is added is used in the well layer, heat resistance is improved, and deterioration of the active layer due to heating during formation of the semiconductor layer grown after the active layer can be suppressed. In addition, when the formation ratio of the well layer is increased to exceed 丨〇% for crystallization and growth, since the growth temperature of the well layer changes depending on the growth temperature of the barrier layer, the formation of the well layer can be increased. On the one hand, the intake is grown at the optimum temperature of the P-limb wall layer, so that a barrier layer having excellent crystal quality can be formed, thereby preventing deterioration of electrical characteristics such as forward voltage. Further, from the n-type GaN-based semiconductor layer to the p-type GaN-based semiconductor layer, the growth surface is formed by a non-polar plane or a semi-polar plane, and thus the Ga polar plane or N (nitrogen) by GaN The influence of the electric field generated by the piezoelectric electric field can be reduced as compared with when the crucible surface is formed. [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a view showing an example of a cross-sectional view of a GaN-based semiconductor light-emitting device of the present invention. Here, the GaN-based semiconductor refers to a group III-V nitride semiconductor which is particularly well known among nitrogen-containing hexagonal compound semiconductors, and a quaternary mixed crystal system of AlxGayInxN (x+y+z=l,,O ^d) indicates. On the sapphire substrate 1, an n-type GaN contact layer 2, an n-type AlInGaN/AlGaN superlattice layer 3, an active layer 4, a P-type A1GaN barrier layer 8, and a p-type GaN contact layer 5 are sequentially laminated, from P pear The GaN contact layer 5 serves to etch a portion of the region to form the electrode 7 on the exposed surface of the n-type GaN contact layer 2. Further, an electrode 6 is formed on the p-type GaN contact layer 5. The active layer 4 has an active layer of a quantum well structure (Quantum Wel1) and forms a structure in which a band gap is larger than a barrier layer of the well layer to sandwich a well layer. The quantum well structure may be one or more, and in this case, it is a multiple quantum well structure of MQW (Multi Quantum Well). It is well known that the heat resistance of AlGaN in a GaN-based semiconductor is very excellent. Therefore, in the present invention, A1 is added to the entire active layer 4 to become a quaternary mixed crystal system AlInGaN', and is formed by AlxiInYlGazlN (x1+Y1+zi = 1, 〇&lt;X1&lt;1, 〇&lt;Y1&lt;1) The well layer, and the multiple quantum well structure of the barrier layer is formed by AlX2InY2GaZ2N (X2 + 126509.doc •10·200832758 Y2+Z2-1 '0$Χ2&lt;1, 〇^γ2&lt;1, γι&gt; γ2). Furthermore, it is also possible to add the AiInGaN/InGaN multi-well structure of the well layer (the above Χ2=〇) or the A1InGaN/GaN multiple quantum of the barrier layer (the above X2=0, Y2=〇) with GaN. Well construction. In the active layer*, the light-emitting wavelength is changed from purple to red by changing the range of Y1S〇&lt;Y1&lt;1, especially in the case where the light-emitting wavelength is 45 〇 or more.

When a wavelength GaN-based semiconductor light-emitting device is used as a target, it is composed of an active layer having a composition of a well layer and a ratio of more than 10%. Fig. 2 shows the structure of the active layer 4 in detail. The active layer 4 is provided with a barrier layer 在 on the side adjacent to the A1InGaN/A1 GaN superlattice layer 3, and a well layer 4b' is laminated thereon, and the barrier layer 4b is laminated with the well layer for several cycles. Forming a final barrier layer 4a' is formed with a P-type GaN contact layer 5 on the last barrier layer. Here, as shown, the barrier layer is blunt by undoped or si doped concentration of 5x] 〇 160m3^ 5xl〇18〇xxx-3x ^ η (\ λ ίζ /\ % , m film; is composed of 7〇~160 A of Al〇〇〇5GaN. On the other hand, the well layer 4b is, for example, a film thickness of 3〇a The non-composite Α1〇·(10) JnGaN is formed, and the well layer and the barrier layer are alternately layered for 5 cycles. Also, A1 can be formed only by adding A1 to the well layer.

GaN. As described above, by adding A1 to the well layer A and the barrier layer of the layer 4 of the active screen 4, it is possible to constitute an active layer having high heat damage resistance. Further, as described above, the barrier layer 4a may be formed of AlGaN or GaN, but in order to improve the luminous efficiency, it is preferable to form Yang (4) (the above Y(4)), and the band gap energy of the barrier layer must be high. In the well layer 126509.doc 200832758 4b, generally, in order to make Υ1 &gt; Υ2, the In composition ratio of the barrier layer 4a is made smaller than the well layer 4b.

The AlInGaN/AlGaN superlattice layer 3 relaxes the stress of AlInGaN and AlGaN having a large difference in lattice constant, and makes the AlInGaN of the active layer 4 easy to grow. The AlInGaN/AlGaN superlattice layer 3 uses the following structure: for example, Si doping Alo.cnlno.osGaN having a heterogeneous concentration of 1 to 5xl018cnT3 and a film thickness of 1 〇A, and a structure having an overlap of GaN alternately with the same Si doping concentration and a film thickness of 20 A for 10 cycles. First, a specific method of forming the active layer 4 when the well layer 4b is AlInGaN and the barrier layer 4a is AlGaN will be described with reference to Fig. 4 . A nitrogen gas (N2) as a carrier gas is supplied, and triethylgallium (TEG, Triethyl gallium) or trimethyl gallium (TMG, Trimethyl gallium), which is a raw material gas of a Ga atom, is supplied as a raw material gas of a nitrogen atom. (NH3), and trimethyl aluminum as a material gas of the A1 atom. Further, when it is of the n-type, decane (SiH4) as a doping gas is also supplied. 4, TEG, TMA, and NH3 (not shown) are continuously circulated in the production of the active layer 4, and only when the well layer 4b is formed, as shown in FIG. The trimethyl indium (TMI) of the atomic raw material gas circulates. Further, the period during which the TMI is supplied and the period during which the supply of the TMI is stopped are alternately set. Thereby, the well layer 4b is formed during the period corresponding to the time L, and the barrier layer 4a is formed during the other period in which the supply of the TMI is stopped, whereby the barrier layer 4a and the well layer 4b are alternately formed. Further, when A1 is not added to the barrier layer 4a to make it GaN, the TMA of FIG. 4 may be discontinuously supplied, and the TMA supply may be intermittently started/stopped to make the TMA intermittent 126509.doc -12-200832758 (interruption) Circulating. Fig. 5 is a view showing the improvement of the heat resistance of the active layer when the well layer 4b and the barrier layer 4a are grown at the same temperature (e.g., 730 °C) in the method of Fig. 4. In FIG. 5, in the GaN-based semiconductor light-emitting device of FIG. 1, after the AlInGaN/AlGaN superlattice layer 3 is formed on the sapphire substrate 1, five periods of AlInGaN well layers and AlGaN barrier layers are formed as the active layer 4 in the above manner. Then, the annealing treatment is performed to check whether the surface of the active layer 4 is blackened due to the composition ratio of the annealing temperature (heat treatment temperature) to A1. The composition ratio of A1 is common to the ® AlInGaN well layer and the AlGaN barrier layer. 5 is a part of the experimental data, and the image data on the surface of the active layer 4 is arranged such that the vertical axis represents the A1 composition (Al/Ga supply ratio) and the horizontal axis represents the heat treatment temperature (annealing temperature). Form the map. For the active layer 4, a layer in which undoped GaN is alternately laminated is used as a barrier layer, and an In composition ratio of the AlInGaN well layer is set to about 20%, and heat treatment at each temperature is performed in a nitrogen atmosphere. And the heat treatment time is ¥ 30 minutes. Further, in order to compare with the case where A1 is added to the active layer, the active layer 4 is set to the previous InGaN/GaN active layer, and the AlInGaN/AlGaN • superlattice layer 3 is set to the InGaN/GaN superlattice layer. With this constitution, heat treatment was performed under the same conditions. Further, the In composition ratio of the InGaN well layer was the same as described above, and was set to about 20%. The dashed line in Figure 5 indicates the boundary line at which the wafer begins to darken. As can also be seen from Fig. 5, in the prior InGaN/GaN active layer, the wafer was observed to be black at 950 °C. However, in the AlInGaN/AlGaN active layer, when the composition ratio of 126509.doc -13 - 200832758 A1 was 0.5%, blackening began at the time of heat treatment at 10 °C. Further, when the composition of A1 is increased so that the composition ratio of A1 is 1.0%, as long as the heat treatment temperature of 1050 ° C is not reached, blackening does not occur, and even at 10 ° C, the active layer does not cause any problem. Compared with the state where the composition ratio of A1 is 1.0%, there is no change when the composition ratio of A1 is increased to 2.0%, so that the heat recovery is not greatly improved. Next, Fig. 6 shows the results of PL (Photoluminescence) measurement. The vertical axis represents the PL intensity (arbitrary unit), and the horizontal axis represents the heat treatment temperature. First, as in the case of FIG. 5, in the configuration of FIG. 1, after the five-cycle AlInGaN well layer and the AlGaN barrier layer or the AlInGaN well layer and the GaN barrier layer are formed as the active layer 4 on the sapphire substrate 1, the change is made. The annealing temperature was carried out, and heat treatment was performed in a nitrogen atmosphere (time is 3 minutes), after which the luminescence spectrum (PL intensity distribution) was measured at room temperature, and the integral value of the PL intensity distribution at each temperature was determined. Curve A1 indicates that the active layer is an MQW structure of an AlInGaN well layer/AlGaN barrier layer and the composition ratio of A1 is 〇 25 〇 / ❶. Curve A2 represents the case of using the previously constructed active layer 'and representing the MQW configuration of the InGaN well layer/GaN barrier layer. Curve A3 indicates that the active layer is an MQW structure of an A1InGaN well layer/GaN barrier layer and the composition ratio of A1 is 1%. Curve A4 indicates that the active layer is the MqW structure of the AlInGaN well layer/AlGaN barrier layer and the composition ratio of A1 is 1%. In the curve A2 using the previously constructed active layer, when the heat treatment at 950 ° C is performed, the PL intensity is sharply reduced, It can be seen that the active layer is deteriorated. This is also consistent with the results of Figure 5. On the other hand, if the composition ratio of A1 is 0.25%, a good PL intensity is exhibited in the vicinity of 126509.doc 200832758 95CTC, and the pL intensity is lowered in the heat treatment at 1000 °C. Therefore, the curve A1 to which A1 is added is compared with the curve A2 using the previously constructed active layer, T°C (50 in the figure. The heat resistance is improved. Further, in the curve A3, only 1% of the A1 is added to the well layer, When it reaches 1 〇〇〇., the luminescence intensity decreases, and the heat resistance is almost the same as that of A1. However, as the composition ratio of A1 increases, the luminescence intensity also decreases. On the other hand, 1% is added to both the well layer and the barrier layer. In the curve A4 of A1, it can be seen from Fig. 5 that the heat resistance is improved compared with A1 or A3, but the luminous intensity is lower than A3.

As described above, from the measurement results shown in Fig. 5 and Fig. 6, it is understood that an increase in heat resistance can be observed by adding a little A1 to the active layer. On the other hand, if the A1 composition ratio in the AlInGaN well layer is increased, the band gap becomes larger and the luminescence tends to be shorter, but in order not to increase the wavelength shift amount, it is desirable to at least A1 in the well layer. The composition ratio is 5% or less. Further, as can be seen from Fig. 6, it is more preferable that the composition ratio of A1 is 1% or less. In addition, in actuality, an LED structure is also produced. However, in the prior InGaN/GaN active layer, at 90 (the temperature of rC or higher, the ?-type layer becomes black when it is formed, so that the LED cannot emit light) In the active layer using AiinGaN for the secondary fabrication, even if the 95 〇ΪΗέp-type GaN layer is formed into a film, it is not subjected to thermal damage. Thus, an LED having good characteristics can be obtained. Next, a well servant as shown in FIG. The temperature modulation is performed differently from the growth temperature of the barrier layer to form the active layer 4. The gas flow pattern is the same as that of Fig. 4. First, after the substrate temperature is lowered to the temperature π, the crystal growth is further performed for a fixed period of time, 4b The film, after the process of lowering the growth temperature to the crucible, is followed by 'in order to make the crystal layer of the barrier layer 4a 126509.doc •15-200832758 grow. When the temperature reaches TX and transports to T2, the temperature is 2 and At the time of Fig. 4 [the crystal growth of the well layer 4b is performed during the period, and then the crystal growth of the next barrier layer is performed again as described above. The growth of the well system is based on the growth of the @P early wall layer when the temperature is fixed. At the temperature rise from T2 During the process of T1, the process is carried out during the T1 period and the temperature is decreased from τι to τ2, thereby alternately forming the barrier layer (4) well layer 4b into a film. Here, η is set at 850t~95 (rc) , τ2 is set at 6 thief ~ delete. c. The temperature rise time from T2 to T1 and the cooling time from τ 丨 to Τ 2 are within $ minutes. And the growth rate of 'well layer 4b and barrier layer 4 &amp; The growth time of the well layer 4b (corresponding to the period L) is set to 〇·86 minutes, the growth time of the barrier layer 4a is set to 7 minutes, the TEG flow rate is set to 74 sccm, the 流量 flow rate is set to 115 SCCm, and the TMA flow rate is set. It is 1〇~2〇〇sccm, etc. In the LED structure of the structure of Fig. 1, when the MQW structure of AlInGaN/AlGaN is formed under different growth temperatures of the well layer and the barrier layer, the phase 乂 can be obtained to fix the temperature. The high internal quantum efficiency of the film-forming sample is considered to be because the quality of the barrier layer is improved by the high temperature of the barrier layer growth temperature, and the heat resistance of the well layer is improved by the addition of A1, so even the barrier layer is The growth temperature is Ma Wen, and there is no thermal damage in the well layer. Figure 7 is by A comparison chart of the forward voltage (vf)_ forward current (If) characteristics when the active layer 4 is grown and the active layer 4 is grown at a fixed temperature, and Z1 indicates that both the well layer 4b and the barrier layer 4a are The vf-if characteristic curve at the same temperature growth, and Z2 represents a Vf-If characteristic curve when the temperature of the well layer and the barrier layer 4a are grown as shown in Fig. 3. The structure of the well layer 4b and the barrier layer 4a is used. The above structure 'has a green light field with an emission wavelength of about 520 nm. 126509.doc -16-200832758 Luminescence It can be seen from Fig. 7 that the driving layer (curve Z2) produced by temperature modulation is often low. Therefore, it is better. For example, when the active layer is formed at a temperature (Z1)' Vf (20 is 4 v or more, when the active layer is formed by temperature modulation (Z2), vf (2G mA) can be obtained as 32~ 34 V 〇

Fig. 8 is a graph comparing brightness and forward current (10) characteristics when the active layer 4 is grown by temperature modulation and when the active layer 4 is grown at a fixed temperature. When both the well layer 4 b and the barrier layer 4 a are grown at the same temperature, the luminance is melody, and the friend 1 indicates that the well layer 4b and the barrier layer 4a are grown as shown in FIG. Brightness_If characteristic curve. The structure of the well layer and the barrier core uses the above structure and has a green light region having an emission wavelength of about 52 〇 nm. As is apparent from Fig. 8, the luminance of the active layer (curve z4) produced by temperature modulation becomes strong in all current domains, so that the luminescence characteristic G is greatly improved. As described above, when A1 is added only to the active layer, heat resistance can be improved, but the characteristics of the GaN-based semiconductor light-emitting device are not sufficient. On the other hand, when only A1 is added and only temperature modulation is performed, the effect is not obtained on the short-wavelength side (the short-wave side which is shorter than the blue light), and on the long-wavelength side (the long-wave side which is longer than the blue light), the well layer The film becomes black, making it impossible to produce a light-emitting element. After adding A1 and performing temperature modulation, a light-emitting element having excellent light-emitting characteristics and electrical characteristics can be produced for the first time. The method of the present invention is effective in a region of the same wavelength of the green light region, but it is observed that the light-emitting element in the long-wavelength region shifts toward the short-wavelength side as the injection current increases. The reason for this is that when the GaN-based semiconductor is grown on the C-plane or the -C plane of the 126509.doc 17 200832758 gem substrate, the wurtzite structure is formed such that the grown surface of the GaN-based semiconductor layer is concentrated on the surface or a -c plane, and having no symmetry in the c-axis direction, and a surface and a back surface are formed on the epitaxial film grown on the e-plane, whereby the active layer is deformed to generate an electric field (piezoelectric electric field), and the influence thereof causes the wavelength of the light to change. The longer the wavelength, and the higher the composition ratio of the well layer, the more significant the phenomenon. Therefore, when a GaN-based semiconductor light-emitting device having a non-polar surface on which a piezoelectric field is not generated is formed as a growth surface, a light-emitting element having almost no wavelength shift can be produced. Further, a GaN-based semiconductor light-emitting device having a semi-polar surface which can suppress the generation of a piezoelectric field as a growth surface can be produced.

A hexagonal crystal structure such as a GaN-based semiconductor, a sapphire substrate, or a 6H-Sic substrate may be referred to as a wurtzite-type crystal structure, and a crystal face or orientation is represented by a so-called Miller index. For example, the c-plane is expressed as (〇〇) 〇1), the a side is expressed as (11-20). The non-polar surface corresponds to a plane orthogonal to the face or the &lt;face, and corresponds to the a face (11-20) and also serves as the 111 face (1〇_1〇) of the crystal cylinder. On the other hand, the semi-polar surface refers to any one of the surface, the surface, and the Ου" surface. Further, the non-polar surface or the semi-polar surface of the growth substrate such as a sapphire substrate, a Sic substrate, or a * substrate is used. When the crystal is grown on the surface of the bulk layer, the grown surface of all the GaN-based semiconductor layers formed is a non-polar surface or a semi-polar surface. For example, when the LED of the structure of Fig. 1 is formed, it is grown. When the GaN-based semiconductor crystal is grown on the r surface of the sapphire substrate 1 on the substrate, the growth surface becomes the a-plane, and thus the LED of FIG. 1 having the non-polar surface as the growth surface 126509.doc -18 - 200832758 can be formed. When the GaN-based semiconductor crystal is grown on the semipolar surface of the sapphire substrate 1, the growth surface of the GaN-based semiconductor is also a semi-polar surface. The method of production is grown by a well-known MOCVD method or the like. After the sapphire substrate 1 is thermally cleaned, the substrate temperature is raised to about 1000 ° C, and a Si-doped n-type GaN contact layer 2 of about 1 to 5 μm is laminated on the r surface of the sapphire substrate 1, and secondly, base The temperature of the plate is lowered to 700 〇C to 800 〇C to form a Si-doped AlInGaN/AlGaN superlattice layer 3, an active layer 4 of MQW structure. Thereafter, the substrate temperature is raised to 950 ～1000 ° C, Further, a Mg-doped p-type AlGaN barrier layer 8 functioning as an electron blocking layer is formed, and secondly, a Mg-doped p-type GaN contact layer 5 of about 0.2 to 1 μm is laminated. As described above, in the active layer 4, Alternately layered with well layer AlxlInY1GazlN (Xl+Yl+Zl = l,0&lt;X1&lt;1,0&lt;Y1&lt;1), barrier layer AlX2InY2GaZ2N(X2+Y2+Z2=l,0$X2&lt;1, Y2&lt;1 After the germanium-type GaN contact layer 5 is formed, the intermediate portion of the p-type GaN contact layer 5 to the n-type GaN contact layer 2 is removed by plate etching such as reactive ion etching to expose the surface of the n-type GaN contact layer 2. Thereafter, the n electrode 7 is formed on the surface of the exposed n-type GaN contact layer 2 by vapor deposition, and the p electrode 6 is formed on the p-type GaN contact layer 5 by vapor deposition.

The p electrode 6 may not be formed on the p-type GaN contact layer 5, and the p-electrode 6 may be formed by laminating a transparent ZnO electrode on the p-type GaN contact layer 5. At this time, Ga doping is formed on the contact layer 5 of the p-type GaN 126509.doc -19-200832758 by, for example, MBE (Molecular beam epitaxy) or PLD (Pulsed Laser Deposition). Hetero Zn0 electrode. Fig. 9 shows an example of forming a led electrode in which a p-electrode and an n-electrode are opposed to each other by using a &6; private 6H_SiC substrate. In the composition of the figure, the thermal conductivity of the sapphire substrate i is poor, about w5 w/(cmK), and both the P electrode side and the η electrode side need to be wired, and when the team substrate is used, there are the following advantages: The conductivity is 1 times (about 49 W/(cm K)) of the sapphire substrate, and the heat is good, and the n-electrode side can be directly soldered to the metal wiring. Therefore, the connection on the ρ-electrode side can be a root. The GaN-based semiconductor crystal is grown on the m-plane of the n-type 6H-SiC substrate 12, whereby the grown surface of the GaN-based semiconductor also becomes a non-polar melon. When the GaN-based semiconductor crystal is grown on the (10_M) plane as the semipolar surface, the growth surface of the GaN-based semiconductor is also (1〇_1-1)0. In the MOCVD method, the substrate temperature is raised to about 1000 ° C, and a Si-doped n-type GaN contact layer 13 is laminated on the non-polar or semi-polar surface of the n-type 6H-SiC substrate 12, and secondly, the substrate temperature is made. Dropped to 700 ° C ~ 80 (TC, forming Si-doped AlInGaN / AlGaN superlattice layer 14, active layer 41 of MQW structure. Thereafter, the substrate temperature is raised to 950 ° C ~ l ° ° C On the left side, a Mg-doped p-type A1 GaN barrier layer 17 functioning as an electron blocking layer is formed, and next, a Mg-doped p-type GaN contact layer 15 is laminated. Finally, a p-electrode 16 is formed by vapor deposition or sputtering. η electrode u. As described above, in the active layer 41 of the MQW structure, the well layer AlxlInY1GazlN is alternately laminated (Xl+Yl+Zl=l, 00&lt;Χ1&lt;1, 〇&lt;Υ1&lt;1), and the barrier layer AlX2InY2GaZ2N (X2+Y2+Z2=l,0$Χ2&lt; 126509.doc -20- 200832758 1,0$ Υ2&lt;1) Fig. 10 shows LD (laser dio) having a ridge structure De, a laser diode) is constructed by laminating an n-type cladding layer 22, an n-type GaN waveguide layer 23, an n-type AlInGaN/AlGaN superlattice layer 24, MQW activity on an n-type GaN substrate 21. After layer 42, p-type AlGaN barrier layer 25, p-type GaN waveguide layer 26, p-type SLS (strained-layer superlattices), p-type GaN contact layer 27, and p-type GaN contact layer 28, The intermediate portion of the p-type GaN contact layer 28 to the p-type GaN waveguide layer 26 is removed to form a ridge structure, and the insulating layer 29 is formed so as to cover the exposed surface of the P-type GaN waveguide layer 26 from the side of the ridge portion. The contact electrode 30 is formed over the upper surface of the insulating layer 29 in contact with the upper surface of the p-type GaN contact layer 28, and thereafter the pad electrode 31 is provided on the contact electrode 30. At this time, the n-type GaN substrate 21 is formed. The surface is a non-polar or semi-polar surface, and the MQW active layer 42 is alternately laminated with a well layer AlXiInYiGaziN (Xl+Yl+Zl=l,0&lt;X1&lt;1,0&lt;Y1&lt;1), barrier layer

AlX2InY2Gaz2N (X2+Y2+Z2=l '0'Χ2&lt;1' 〇€Υ2&lt;1). Further, the n-type cladding layer 22 is composed of an n-type AlGaN layer or a superlattice layer in which n-type AlGaN and an n-type GaN layer are alternately laminated. The Ρ-type SLS cladding layer 27 has a strained layer superlattice structure. The layer is a structure in which P-type AlGaN and p-type GaN are alternately laminated. Further, the p-type AlGaN P-denier layer 25 to the P-type GaN contact layer 28 which are laminated higher than the MQW active layer 42 are at a substrate temperature of 950. (3~l〇〇〇°C is grown. Further, when each of the above semiconductor layers is produced, hydrogen/nitrogen as a carrier gas is supplied, and triethylgallium (TEGa) or trimethylgallium (TMG) is supplied. Ammonia 126509.doc -21-200832758 (NH3), trimethylaluminum (TMA), trimethyl indium (ΤΜίη), etc., corresponding to the reaction gas of each semiconductor layer, when supplied as a doping gas Hydrane (SiHO), when it is a ρ type, supplies a necessary gas such as cp2Mg (Bis_ (Cyclopentadieuy GMagnesiimi), which is a doping gas, and grows sequentially in the range of 65 (TC~lOOOO:). The desired conductive semiconductor layer having a necessary thickness can be formed by a desired composition. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of a cross-sectional structure of a GaN-based semiconductor light-emitting device of the present invention. FIG. 2 shows a GaN of the present invention. A multi-quantum well structure diagram of an active layer in a semiconductor light-emitting device. Fig. 3 shows a method of forming an active layer by temperature modulation. Figure 4 shows a gas flow pattern when the active layer crystal grows. Figure 5 shows the addition to the active layer. Proportion and heat treatment temperature Figure 6 shows the effect of heat treatment temperature on the active layer in the unit of the active layer. Figure 7 shows the electrical growth of the active layer at a fixed temperature and by temperature modulation. Comparison of characteristics Fig. 8 shows a comparison of luminescent characteristics when the active layer is grown at a fixed temperature and grown by temperature modulation. Fig. 9 shows an example of a cross-sectional structure of a GaN-based semiconductor light-emitting device of the present invention. 126509.doc -22 - 200832758 Fig. 10 shows an example of a cross-sectional structure of a GaN-based semiconductor light-emitting device of the present invention. [Description of main components] 1 Sapphire substrate 2 η-type GaN contact layer 3 AlInGaN/AlGaN superlattice layer, 4 Active layer 4a ® 4b barrier Well layer 5 p-type GaN contact layer 6 P electrode 7 η electrode 8 p-type AlGaN barrier layer 126509.doc -23-

Claims (1)

200832758 X. Patent Application Range: 1. A GaN-based semiconductor light-emitting device, characterized in that it comprises an active layer having a quantum well structure, and the active layer comprises AlxlInY1Gaz〗N (Xl+Yl+Zl = l , 〇&lt;;Χ1&lt;1 ' 〇&lt;Υ1&lt;1) well layer and Alx2lnY2Gaz2N barrier layer (χ2+γ2 + Z2=l,〇$χ2&lt;ΐ,〇gY2&lt;1,Υ1&gt;Υ2), and the above-mentioned well layer consists of Ιη More than 10%. 2. A GaN-based semiconductor light-emitting device, comprising: an active layer having a quantum well structure, wherein the active layer comprises AlxlInY1GazlN (Xl+Yl+Zl = l, 〇&lt;Χ1&lt;1 ' 〇&lt;Υ1&lt; 1) The well layer and the Alx2lnY2Gaz2N barrier layer (χ2+γ2 + Z2=l, 〇gX2&lt;1, 〇$Υ2&lt;1, γι&gt; γ2), and the growth temperature of the well layer is different from the growth temperature of the barrier layer. 3. The GaN-based semiconductor light-emitting device of claim 2, wherein the 井η composition of the well layer is greater than 10%. 4. The GaN-based semiconductor light-emitting device according to any one of claims 1 to 3, wherein the well layer has an A1 composition of 5% or less. The GaN-based semiconductor light-emitting device according to any one of claims 1 to 3, wherein the well layer has an A1 composition of 1% or less. The GaN-based semiconductor light-emitting device according to any one of claims 1 to 5, wherein at least the crystal growth surface of the active layer is formed of a nonpolar surface or a semipolar surface. 126509.doc