TW540164B - Radiation-emitting semiconductor-body and its production method - Google Patents

Abstract

The radiation-generating layer-sequence (2) is grown directly on a window-layer (3), which has one or several overlapped AlGaAs-layers (4, 5, 6). The AlGaAs-layers are produced by means of liquid-phase-epitaxy or a similar method and have respectively an Al-content far from the layer-sequence (2), in which AlGaAs is transparent for the generated radiation. The Al-content decreases in each AlGaAs-layers (4, 5, 6) in the direction to the active layer-sequence (2). The Window-layer (3) is alternatively composed of a non-supporting AlGaAs-epitaxy substrate (7), which has Al-content, in which AlGaAs is transparent for the generated radiation.

Description

540164 V. Description of the invention (5) The total thickness of the active layer sequence 2 is usually only a few μm.

The AlGaAs layers 4, 5, 6 are preferably made by liquid phase epitaxy (LPE) and have a thickness of up to 50 µm. The aluminum depletion generated in the liquid phase epitaxy in the growth direction can be "undamaged" by the AlGaAs multilayer structure of the present invention. According to the present invention, AlGaAs having two or more AlGaAs layers Based on a multi-layer structure, an unsupported and transparent AlGaAs-LPE layer with a large layer thickness can be made through multiple LPE growth (or boot) processes. The total thickness of the layer has sufficient mechanical stability. Layers between 100 and 200 μηι can be made very simply as described above. The temperature at the time of deposition is 700-1000 ° C. In other words, the Al content in AlGaAs multilayer structure 4, 5, 6 is not Beyond a larger layer thickness (> 1000 nm), the light generated in the active layer must fall below the transparent range, and the light emitted in the AlGaAs layer will not be greatly affected. (≫ 3%) absorption. However, these thin layers (10-30 Onm) whose aluminum content is less than the transparent range (for example, compare the interface from the AlGaAs multilayer structure to the active layer sequence 2 shown by the circle in Figure lb) Zone 10) is particularly useful as a cover layer for AlGaAs layers with a high aluminum content, This prevents the aluminum-containing layer from being oxidized in the air, otherwise the oxidized layer is an undesired stop layer for electrical isolation for the subsequent epitaxial layers of the active layer sequence 2. In the method for manufacturing the radiation-emitting semiconductor body shown in Figs. 2a to 2e, the epitaxial substrate 7 (which is made of, for example, GaAs or other suitable materials) is firstly subjected to liquid phase epitaxy on the method The two AlGaAs layers 4, 5, and 6 are sequentially grown by the crystal method. These steps are made at the first process temperature (540,164, 5. Description of the invention (7) (Freez) method (VGF). In order to obtain the electrical contact area For such a wafer structure facing each other, the epitaxial substrate Π must be doped to have conductivity. The semiconductor layer sequence of the present invention is also particularly suitable for making a semiconductor body, in which the window layer 3 is affinity-bonded or affinity-bonded. The wavelength of the incoming radiation is in the infrared region or the red spectral region and is less than 8 70 nm. The absorption edge of the window layer 3 is adjusted to a wavelength shorter than the radiation that is coupled out or coupled in. The layer of the invention Sequences can be advantageously used for vertical tables The emitting semiconductor laser structure or used in the light-emitting diode structure. The semiconductor layer of the semiconductor body of the present invention is formed in the following manner depending on the component structure:-Each light-emitting diode (LEDs) is electrically conductive Layer (possibly some other Bragg reflective layers), which is transparent to the light generated in the active layer. The active layer is usually composed of one or more quantum films. A configuration is The layer sequence on the active layer may also be composed of a conductive layer to form an ohmic connection with the electrical contact area. Due to the permeability of the AlGaAs-multilayer structure and the AlGaAs-Jiajing substrate, part of the low-energy beam can be passed by the active layer The back side of the AlGaAs-window layer is reflected to the back side of the AlGaAs-window layer through a reflective back contact area and a part is coupled out to the side and / or forwardly. Therefore, a transparent AlGaAs-multilayer structure or a transparent AlGaAs-epitaxial substrate can also be used to form an LED structure for backward emission. The epitaxial process of the active LED structure is performed directly on the window layer, that is, on the AlGaAs multilayer structure or -9-540164. V. Description of the invention (8)

AlGaAs epitaxial substrate is carried out. At this time, it is not necessary to form a partially conductive transparent substrate carrier contact area by connecting or fusing technically expensive wafers afterwards. -In resonant light emitting diodes (RCLEDs) composed of conductive layers, they have feedback Braggs with a small number of cycles (typically 5 cycles, so laser power g is not used) The reflective layer is transparent to the light generated in the active layer. The active layer is usually composed of one or more quantum films. The total thickness is an integral multiple of one-half the emission wavelength. The position of the quantum film is in the abdomen position of the standing wave field. The layer sequence subsequently configured consists of a Bragg-reflective layer whose phase has been adjusted. These layers may additionally consist of a conductive layer for later ohmic metal contact. Due to the transparency of the AlGaAs multilayer structure or the AlGaAs epitaxial substrate, part of the low-energy beam can be reflected by the active layer through the backside of the AlGaAs-window layer or through the reflective backside contact area to the backside of the AlGaAs-window layer and A portion is coupled out to the side and / or forward. Therefore, the LED structure for backward emission can also be formed by means of a transparent AlGaAs-multilayer structure or a transparent AlGaAs-epitaxial substrate. The Jiajing process of the active RCLED structure is performed directly on the AlGaAs-multilayer structure or AlGaAs-epitaxial substrate. At this time, it is not necessary to form a partially conductive transparent substrate carrier contact afterwards by technically expensive wafer bonding or fusion. Area. -In the vertical surface-emitting laser structure coupled back through the substrate-10-540164 V. Description of Invention (9) (VCSEL), which is composed of a conductive layer and has a large number of cycles (typically 22) Cycle) of the feedback Bragg reflector, so the higher-quality resonator can use the laser function with less absorption when the current is greater than the threshold. The active layer is usually composed of one or more quantum films. The total thickness is an integral multiple of one-half the emission wavelength. The position of the quantum film is in the abdomen position of the standing wave field. The layer sequence subsequently configured consists of a phase-adjusted Bragg-reflective layer (typically 27 cycles), which serves as a higher-quality reflector for the beam generated in the active layer (R is approximately 0.99) . These layers may additionally consist of a conductive layer for later ohmic metal contact. Due to the transparency of the AlGaAs-multilayer structure or AlGaAs-Jiajing substrate, this part of the low-energy laser beam (which leaves the laser resonator due to the smaller reflectivity of the feedback Bragg reflective layer) ) Without absorption, it is coupled out through the AlGaAs-back layer. With the aid of a transparent AlGaAs-multilayer structure or an AlGaAs-epitaxial substrate, a VCSEL structure that can be emitted backward can be made. The epitaxial process of the active VCSEL structure is performed directly on the window layer, that is, on the AlGaAs multilayer structure or on the AlGaAs Jiajing substrate. At this time, there is no need to form a part of the conductivity by technically expensive wafer bonding or fusion. The transparent substrate carrier contact area. Explanation of symbols 1 Semiconductor body 2 Layer sequence 3 Window layer 4,5,6 AlGaAs layer -11- 540164 10 Epitaxial substrate Contact layer V. Description of the invention () 7,11 8,9 -12-

Claims (1)

540164 q broken Lf month H supplementary soil 6. Patent application range 90 1 27499 "Semiconductor body capable of emitting radiation and its manufacturing method" patent case (amended in April 1992) 6. Scope of patent application: 1. A type that can be issued Radiation semiconductor body (1), comprising: a layer sequence (2) that can emit radiation and a window layer (3) that is at least partially transparent to the generated radiation, and is characterized by: AlGaAs layers (4,5,6) with one or more sequentially arranged, which are made by liquid phase epitaxy or the same method, and each have an A1 content at a distance from the layer sequence (2) This Al content makes AlGaAs transparent to the generated light beam and this Al content decreases gradually in each AlGaAs layer (4, 5, 6) in the layer sequence (2) for radiation generation. 2. For example, the radiation-emitting semiconductor body (1) in the scope of patent application, wherein the AlGaAs layer (6) adjacent to the layer sequence (2) has a passivation layer in the junction area to the layer sequence (2) . 3. The radiation-emitting semiconductor body (1), such as in the scope of patent application, wherein the AlGaAs layer (6) adjacent to the layer sequence (2) has an aluminum content in the junction area to the layer sequence (2) The AlGaAs layer is not oxidized or only slightly oxidized in an atmosphere containing oxygen, so the AlGaAs layer can be used as a passivation layer. 4. The radiation-emitting semiconductor body (1), such as the scope of application for patent No. 3, wherein the layer thickness of the junction area is between 10nm and 30nm. ^ 164 Six patent application scope 5. The radiation-emitting semiconductor body (1) according to any of claims 1 to 4 of the scope of patent application, wherein the wavelength of a radiation which is coupled out through or coupled through the window layer (3) is less than 870 nm and the window layer (3) The absorption edge is in a shorter wavelength as a whole by changing the aluminum content. 6. The radiation-emitting semiconductor body (1) according to item 1 of the patent application scope, wherein the AlGaAs layer (4, 5, 6) is doped to have conductivity. 7. If the radiation-emitting semiconductor body ㈠) of item 1 of the patent application scope, wherein the thickness of the window layer (3) is greater than 5 μm. δ. The radiation-emitting semiconductor body (1) in the scope of patent application No. 7 in which the window layer (3) has an unsupported substrate having a thickness between 100 μm and 100 μm. 9. The radiation-emitting semiconductor body (1), as described in the first patent application, wherein the window layer (3) is grown by liquid phase epitaxy or a similar method, and the layer sequence (2) is by gas phase epitaxy , Especially by metal organic vapor phase epitaxy or molecular beam epitaxy or similar epitaxial growth. 10. A radiation-emitting semiconductor body (1), comprising: a sequence of radiation-emitting layers (2) and a window layer (3) that is at least partially transparent to the radiation produced, It is characterized by: The window layer (3) is formed by an unsupported epitaxial substrate (1 1), which is composed of AlGaAs and has an aluminum (A1) content. This aluminum content makes AlGaAs to the radiation generated Is permeable. 540164 _______I You》 "i U ^ —Sixth, the scope of patent application; 11. If the patent application scope of the tenth of the semiconductor body (1) that can emit radiation, one of them is coupled out through the window layer (3) Or the coupled radiation has a wavelength of less than 870 nm and the absorption edge of the window layer (3) is in a shorter wavelength. 12 The radiation-emitting semiconductor body (1) according to claim 10 or 11, wherein the epitaxial substrate is made by the Vert i cal Gradient Freeze method. Π The radiation-emitting semiconductor body (1), such as the scope of patent application No. 1 or 10, wherein the window layer (3) is doped to have conductivity. 14. The radiation-emitting semiconductor body (1), such as in the scope of patent application No. 1 or 10, wherein the layer sequence (2) has a semiconductor laser structure for vertical surface emission. 15. For example, a radiation-emitting semiconductor body (1) in the scope of application for a patent, wherein the layer sequence (2) has a light-emitting diode structure. 16. —A method for manufacturing a semiconductor body (1) capable of emitting radiation, the semiconductor body (1) is any one of items 1 to 9 or 13 to 15 (which According to any one of items 1 to 9), it is characterized by the following steps: a) preparing a crystal substrate (7); b) at the first process temperature by liquid phase epitaxy and An AlGaAs layer (4, 5, 6) is grown on the epitaxial substrate (7); c) the AlGaAs layer (4, 5, 6) is formed by metal organic vapor phase epitaxy or molecular beam epitaxy at the second process temperature; The layer sequence is grown on 540164 in September of the following year, and the structure is revised. 6. The scope of patent application (2) 0 17. The manufacturing method of item 16 in the scope of patent application, wherein the first process temperature is between 70 ° C and Between 1 0 0 0 ° C, the second process temperature is between 400 ° C and 800 ° C. 18. The manufacturing method according to claim 16 or 17, wherein the Jiajing substrate (7) is removed after step c). ia — a manufacturing method of a semiconductor body (1) that can emit radiation, the semiconductor body (1) is the patent application for item 10, 11 or 12 or item 1 3, 1 4 or 15 (which is attached to item 1 0, 11 or 12), characterized by the following steps: a) preparing an unsupported epitaxial substrate (11), which is composed of an AlGaAs multilayer structure and has an A1 content, such a The content of 1 makes AlGaAs transparent to the generated radiation, b) the layer sequence is grown on the epitaxial substrate by metal organic vapor phase epitaxy or molecular epitaxy at the second process temperature (2 ). 20. The manufacturing method according to item 19 of the scope of patent application, wherein the epitaxial substrate is made by a Vertical Gradient Freeze (VGF) method. 21 · —A method for manufacturing a substrate (3), which is used to grow a semiconductor body capable of emitting radiation, which is characterized by the following steps: a) preparing an epitaxial substrate (7); b) by liquid phase Jiajing A * AlGaAs layer (4,5,6) is grown on the Jiajing plate (7). The A1 content in the epitaxial layer decreases with the growth thickness of 540164. 6. The scope of the patent application gradually increases and the AlGaAs layer must be selected The thickness is such that the A1 content in it is not less than the radiation generated in the structure that can emit radiation-or it is less than the penetration limit only when the thickness reaches 30nm; c) repeat step b) until the substrate (by AlGaAs Layer (4,5,6) to the desired thickness. 22. A substrate (3) for the growth of a semiconductor body capable of emitting radiation, characterized in that it has one or more sequentially arranged AlGaAs layers (4, 5, 6), which are epitaxially formed by liquid phase And similar methods and have an average A1 content, this A1 content makes AlGaAs transparent to the radiation generated in a radiation-emitting semiconductor body, and in each AlGaAs layer From the side facing the first main surface of the substrate (3), the AlGaAs has a decreasing direction in a direction facing the side facing the second main surface of the substrate (3), which faces the first main surface. The A1 content, where the A1 content is not less than the radiation produced or less than the penetration limit 値 only when the thickness reaches 30nm.