TWI593132B - Method of manufacturing photoelectric device - Google Patents

Description

Photoelectric element manufacturing method

The invention discloses a method for manufacturing a photovoltaic element, in particular to a method for manufacturing an electrode of a photovoltaic element.

As semiconductor materials are increasingly used in Photoelectric Devices such as Light-emitting Diodes (LEDs), Laser Diodes (LDs), and Photovoltaic Celles, Reducing production costs and simplifying today's process steps to increase production efficiency has become one of the issues that the industry is eager to solve.

1A to 1G are schematic views showing the structure of a conventional photovoltaic device manufacturing process; as shown in FIG. 1A, a substrate 10 is first provided, wherein the substrate 10 is a conductive substrate; and then, as shown in FIG. 1B, a semiconductor is formed. The laminate 12 is disposed on the substrate 10, wherein the semiconductor laminate 12 includes at least a first conductive semiconductor layer 120, an active layer 122, and a second conductive semiconductor layer 124 from top to bottom; A metal layer 14 is formed on the light-emitting layer 12 by an evaporation technique; then, as shown in FIG. 1D, a photoresist 16 is formed on the metal layer 14; subsequently, as shown in FIG. 1E, Light passes through the reticle 18 to cause a portion of the photoresist 16 to react, leaving only a portion of the photoresist 16' on the metal layer 14. Next, as shown in FIG. 1F, the metal layer 14 not covering the photoresist 16 is etched, To form a first electrode 20; finally, as shown in FIG. 1G, the photoresist 16 is removed, and a second electrode 22 is formed by vapor deposition on the substrate 10 to obtain a photovoltaic element 100.

It is known from the above-described conventional method for manufacturing a photovoltaic element that the size and position of the electrode in the conventional photovoltaic element are defined by the size and position of the mask aperture 180 in the mask 18. However, generally, the above steps of forming a metal layer by an evaporation technique can only use one metal material, and the selection of the metal material is also limited by the evaporation technology itself. Moreover, after forming the metal layer, it is necessary to further utilize the techniques of exposure, development, etching, and photoresist removal to remove part of the metal layer. In order to form an electrode, the photovoltaic device manufacturing process and manufacturing cost are increased.

SUMMARY OF THE INVENTION The object of the present invention is to provide a method for fabricating a photovoltaic element comprising the steps of forming a metal paste on a semiconductor stack by a printing technique, and providing an energy to form the metal paste into a metal electrode, wherein the metal electrode and the semiconductor layer are laminated. An ohmic contact is formed.

Another object of the present invention is to form a metal electrode by a printing technique to reduce the manufacturing process and cost of the photovoltaic element.

Still another object of the present invention is to form a metal electrode using printing techniques to increase the choice of metal electrode material, thereby increasing the variety of photovoltaic element products.

The purpose, technical contents, features and effects achieved by the present invention will be more readily understood by the detailed description of the embodiments and the accompanying drawings.

10‧‧‧Substrate

12‧‧‧Semiconductor laminate

120‧‧‧First Conductive Semiconductor Layer

122‧‧‧Active layer

124‧‧‧Second conductive semiconductor layer

14‧‧‧metal layer

16, 16'‧‧‧Light resistance

18‧‧‧Photomask

180‧‧‧Mask hole

20‧‧‧First electrode

22‧‧‧second electrode

100‧‧‧Optoelectronic components

24, 44, 70‧‧‧ substrates

26, 46, 72‧‧‧ semiconductor stack

260, 460‧‧‧ first conductive semiconductor layer

262, 462‧‧‧ active layer

264, 464‧‧‧Second conductive semiconductor layer

28, 34, 38‧‧‧metal glue

30, 35, 40, 52‧‧‧ energy

32, 36, 42‧‧‧ electrodes

200, 300, 400, 500‧‧‧ photoelectric components

48, 74‧‧‧ first metal glue

50, 78‧‧‧Second metal glue

54, 76‧‧‧ first electrode

56, 80‧‧‧ second electrode

60‧‧‧ Screen

62‧‧‧ scraper

602‧‧‧ mesh

720‧‧‧First n-type semiconductor layer

722‧‧‧First p-type semiconductor layer

720'‧‧‧second n-type semiconductor layer

722'‧‧‧Second p-type semiconductor layer

724‧‧‧First pn junction

724’‧‧‧Second pn junction

726‧‧‧ Tunneling joint structure

82‧‧‧Energy

84‧‧‧Anti-reflective layer

1A to 1G are schematic views showing the structure of a conventional photovoltaic element manufacturing process.

2A to 2E are schematic views showing the structure of a manufacturing process according to an embodiment of the present invention.

Figure 3 is an enlarged cross-sectional view showing the structure of the embodiment of the present invention.

4A to 4C are schematic views showing the structure of a manufacturing process according to another embodiment of the present invention.

5A to 5D are schematic views showing the structure of a manufacturing process according to still another embodiment of the present invention.

6A to 6F are schematic views showing the structure of a manufacturing process according to still another embodiment of the present invention.

The present invention discloses a technique for forming an ohmic contact electrode with a semiconductor stack on a semiconductor stack by using a printing technique; in addition, the disclosed technology can be widely applied to a light-emitting diode (LED). In the manufacturing process of different photoelectric elements such as a laser diode (LD) and a solar cell (Photovoltaic Cell), in order to make the description of the present invention more detailed and complete, the following description will be made with reference to the drawings.

2A to 2E are schematic views showing the structure of a manufacturing process according to an embodiment of the present invention.

As shown in FIG. 2A, a substrate 24 is first provided, and on the substrate 24 A semiconductor layer 26 is formed on the semiconductor layer 26, and the semiconductor layer 26 includes at least a first conductive semiconductor layer 260, an active layer 262, and a second conductive semiconductor layer 264 from top to bottom. The material of layer 26 may be selected from materials such as gallium nitride (GaN) series, aluminum gallium indium phosphide (AlGaInP) series or gallium arsenide (GaAs) series.

Further, as shown in FIG. 2B, a metal paste 28 is formed on the semiconductor laminate 26 by a printing technique; in this embodiment, a screen print technique is employed, first providing a screen 60, using a doctor blade. 62, the metal glue 28 is printed on the semiconductor laminate 26 by the mesh 602. By controlling the thickness T of the screen and the size of the mesh 602 in the screen 60, the area of the metal paste 28 covering the semiconductor laminate 26 and the metal glue are defined. 28 thickness.

The metal glue 28 includes metal particles and a solvent, wherein the material of the metal particles is selected from the group consisting of gold (Au), silver (Ag), copper (Cu), molybdenum (Mo), nickel (Ni), and zinc (Zn). At least one material of a group consisting of tin (Sn), aluminum (Al), beryllium (Be), germanium (Ge), palladium (Pd), titanium (Ti), and platinum (Pt) and alloys thereof, and metal particles The size is between 1 nm and 1000 nm, preferably less than 100 nm. Further, in one embodiment, the solvent in the metal glue 28 is an organic solvent.

Next, as shown in FIG. 2C, an energy 30 is provided on the metal glue 28. In one embodiment, the energy 30 is provided as a thermal energy to raise the temperature of the metal glue 28 when the temperature reaches 100 degrees Celsius. At 1200 °C, since the boiling point of the organic solvent in the metal glue 28 is low, the metal glue 28 is first evaporated and the residual metal particles are sintered in a high temperature environment to form a porous metal block to form an electrode 32. 3 is a cross-sectional view showing a 30000-fold enlargement of an embodiment of the present invention; as shown in FIG. 3, the electrode 32 formed by the metal paste after high-temperature sintering is tightly bonded to the semiconductor laminate 26 and is in ohmic contact with the semiconductor stack 26 ( Ohmic contact).

In addition, if the substrate 24 is a conductive substrate made of materials such as Silicon, SiC, ZnO, GaAs, GaP or Ge (Ge), As shown in FIG. 2D, another metal paste 34 is formed under the substrate 24 again by using a printing technique; finally, as shown in FIG. 2E, an energy 35 is supplied to heat the metal paste to form another electrode 36; The step of obtaining a photovoltaic element 200.

4A to 4C are schematic views showing the structure of another embodiment of the present invention. As shown in FIG. 4A, if the substrate 24 is an insulating substrate such as sapphire, glass, diamond, etc., the second C-figure can be used. The substrate 24 in the illustrated structure is removed by etching, mechanical polishing or laser lift-off; and, as shown in FIG. 4B, the semiconductor laminate 26 is printed using the printing technique. Another metal paste 38 is formed on the surface in contact with the substrate 24 first; finally, as shown in Fig. 4C, an energy 40 is provided to cause the metal paste 38 to form another electrode 42; thereby obtaining another photovoltaic element 300.

5A to 5D are schematic views showing the structure of a manufacturing process according to still another embodiment of the present invention.

As shown in FIG. 5A, a substrate 44 is provided, and a semiconductor stack 46 is formed on the substrate 44, wherein the semiconductor stack 46 includes at least a first conductive semiconductor layer 460, an active layer 462 from top to bottom, and A second conductive semiconductor layer 464. In addition, in the embodiment, the substrate 44 is an insulating substrate.

Subsequently, as shown in FIG. 5B, the upper surface of the portion of the semiconductor stacked layer 46 is etched by the lithography etching technique until the second portion of the second conductive type semiconductor layer 464 is exposed; and then, as shown in FIG. 5C, using printing techniques, respectively A first metal paste 48 and a second metal paste 50 are formed on the upper surface of the first conductive type semiconductor layer 460 and the exposed surface of the second conductive type semiconductor layer 464.

Finally, as shown in FIG. 5D, an energy 52 is provided to increase the temperature of the first metal glue 48 and the second metal glue 50, so that the first metal glue 48 and the second metal glue 50 are respectively sintered in a high temperature environment. An electrode 54 and a second electrode 56 form a photovoltaic element 400.

FIG. 6A to FIG. 6F are schematic diagrams showing a manufacturing process according to still another embodiment of the present invention. As shown in FIG. 6A, a substrate 70 made of germanium (Ge) is provided, and a semiconductor stack 72 is formed on the substrate, wherein the semiconductor stack is formed. The material of layer 72 comprises one or more substances selected from the group consisting of gallium (Ga), aluminum (Al), indium (In), arsenic (As), phosphorus (P), nitrogen (N), and cerium (Si). Groups, such as gallium arsenide (GaAs) series, aluminum gallium indium phosphide (AlGaInP) series, gallium nitride (GaN) series, gallium indium phosphide (GaInP) series, indium phosphide (InP), indium phosphide InGaAsP series, AlGaAs series, AlGaInAs series, InGaNAs series, InGaN series or Si (Si), The semiconductor stack 72 includes at least one pn junction formed by stacking the first conductive semiconductor layer and the second conductive semiconductor layer. In this embodiment, the semiconductor laminate 72 includes a first n from top to bottom. The semiconductor layer 720, the first p-type semiconductor layer 722, the second n-type semiconductor layer 720', and the second p-type semiconductor layer 722' are stacked to form a first pn junction 724 and a second pn junction 724. The first p-type semiconductor layer 722 and the second n-type semiconductor layer 722' further include a tunnel junction structure 726; then, as shown in FIG. 6B, a metal paste 74 is formed by using a printing technique. On the semiconductor stack 72; in this embodiment, the printing technology system Using screen printing techniques, a screen 60 is first provided, and a first metal paste 74 is printed from the mesh 602 onto the semiconductor stack 72 by a doctor blade 62.

Subsequently, as shown in FIG. 6C, an energy 82 is provided to increase the temperature of the first metal paste 74, and the first metal paste 74 is sintered in a high temperature environment to form the first electrode 76; finally, as shown in FIG. 6D, The second metal paste 78 is again formed under the substrate 70 by a printing technique, and then, as shown in FIG. 6E, the second metal paste 78 is sintered at a high temperature to form the second electrode 80 to obtain a photovoltaic element 500.

In addition, in the embodiment, as shown in FIG. 6F, the step of forming an anti-reflection layer 84 on the semiconductor laminate 72 is further included to increase the probability of light entering the semiconductor laminate 72.

As described above, the electrode forming method disclosed in the present invention uses a printing technique to form a metal paste on a semiconductor laminate, and further provides an energy to form a metal electrode into the metal electrode; the screen printing technology can easily control the printed metal paste. The area and thickness can improve the time-consuming problem of the conventional vapor-deposited metal layer, and at the same time simplify the process of defining the electrode size and position by using the micro-etching technique in the conventional photovoltaic device manufacturing process, thereby effectively reducing the photoelectric element. manufacturing cost.

The embodiments described above are merely illustrative of the technical spirit and the features of the present invention, and the objects of the present invention can be understood by those skilled in the art, and the scope of the present invention cannot be limited thereto. That is, the equivalent variations or modifications made by the spirit of the present invention should still be included in the scope of the present invention.

44‧‧‧Substrate

46‧‧‧Semiconductor laminate

460‧‧‧First Conductive Semiconductor Layer

462‧‧‧Lighting layer

464‧‧‧Second conductive semiconductor layer

54‧‧‧First electrode

56‧‧‧second electrode

400‧‧‧Optoelectronic components

Claims (10)

A method of fabricating a photovoltaic device, the method comprising: providing a semiconductor stack comprising a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer, the semiconductor laminate material comprising nitride a material of a gallium (GaN) series, an aluminum gallium indium phosphide (AlGaInP) series or a gallium arsenide (GaAs) series; providing a first metal paste on the second conductive semiconductor layer; and providing an energy to enable the first a metal paste forms a first electrode, wherein the first electrode and the second conductive semiconductor layer are electrically connected, wherein the first metal paste comprises metal particles, and the size of the metal particles is between 1 nm and 100 nm. . The method of manufacturing a photovoltaic device according to claim 1, wherein the method further comprises: providing a second metal paste under the first conductive semiconductor layer; and providing an energy to form the second metal paste a second electrode, wherein the second electrode is electrically connected to the first conductive semiconductor layer. The method of manufacturing a photovoltaic device according to claim 1, the method further comprising: etching a portion of the semiconductor laminate to expose the first conductive semiconductor layer; and providing a second metal paste to the first conductive semiconductor layer And providing an energy to form the second metal paste to form a second electrode, wherein the second electrode is electrically connected to the first conductive semiconductor layer. The method of manufacturing a photovoltaic element according to claim 3, wherein the second metal paste comprises metal particles and a solvent. The method of manufacturing a photovoltaic element according to claim 1, wherein the first metal paste is formed on the second conductive semiconductor layer by a printing technique. The method of manufacturing a photovoltaic element according to claim 1, wherein the first metal paste comprises metal particles and a solvent. The method of manufacturing a photovoltaic element according to claim 1, wherein the energy is a thermal energy. The method for manufacturing a photovoltaic element according to claim 1, further comprising forming An antireflective layer is applied to the semiconductor stack. A photovoltaic element comprising: a semiconductor stack comprising a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer comprising gallium nitride (GaN) a series of materials, an aluminum gallium indium phosphide (AlGaInP) series or a gallium arsenide (GaAs) series; and a first electrode, wherein the first electrode and the second conductive semiconductor layer are electrically connected, the first electrode Contains multiple pores. The photovoltaic element according to claim 1 or 9, which is a light-emitting diode, a laser diode or a solar cell.