CN101924162A - Method for manufacturing copper indium gallium selenide compound film - Google Patents

Abstract

The invention relates to a method for manufacturing a copper indium gallium selenide compound film, which comprises the following steps: providing a substrate; forming an adhesive layer on the substrate; forming a metal electrode layer on the adhesive layer; forming a precursor stacked film layer on the metal electrode layer, wherein the precursor stacked film layer comprises a plurality of copper-gallium alloy layers and at least one copper-indium alloy layer sandwiched between the copper-gallium alloy layers; performing an annealing process to convert the precursor stack film into a copper indium gallium alloy layer; and performing a selenization process to convert the copper indium gallium selenide alloy layer into a copper indium gallium selenide compound layer.

Description

Manufacturing method of copper indium gallium selenide thin film

technical field

The present invention relates to the manufacture of compound semiconductor thin films, and in particular to a method for manufacturing copper indium gallium diselenide (CIGS) compound thin films.

Background technique

At present, solar cells are mainly based on silicon wafer solar cells. However, since the manufacture of silicon wafer solar cells requires a large-scale factory building and consumes a lot of energy, its material cost and manufacturing cost are still high. And based on the limitations of physical properties, the thickness of silicon wafer solar cells is usually not less than 200 μm, so a lot of silicon raw materials need to be used.

Therefore, in recent years, many other types of solar cell manufacturing technologies different from silicon wafer solar cells have been developed, one of which is the IB-IIIA-VIA ₂ compound using copper indium gallium diselenide (CIGS) The thin film solar cell (thin film solar cell) of the material, its application chemical formula is CuInGaSe ₂ Copper indium gallium selenide (CIGS) compound thin film has extremely wide absorption spectrum range and has quite good stability, thus can be used as the thin film solar cell Absorber (absorber) purposes. Through the application of the above-mentioned copper indium gallium selenide compound thin film, thin film solar cells can be prepared using relatively cheap glass, plastic or stainless steel substrates, and their thickness can be reduced compared with traditional silicon wafer solar cells, which is conducive to solar energy. Applications such as mass production and large area production of batteries.

At present, the copper indium gallium selenide compound thin film mainly adopts the sputtering process to form multiple precursor film layers including metals, alloys and compounds on the substrate, and then uses the selenization process to treat these sputtered on the substrate. The precursor film layer is used to complete the production of the copper indium gallium selenide compound thin film.

Please refer to FIG. 1-2, which shows a known manufacturing method of CIGS thin film.

As shown in FIG. 1 , firstly, a substrate 100 is provided, such as a substrate made of glass, metal foil, or polymer material. A molybdenum metal layer 102 is formed on the substrate 100 with a thickness of about 500-1200 nm. Then, a copper-gallium alloy layer 104 , an indium metal layer 106 and another copper-gallium alloy layer 108 are sequentially formed on the molybdenum metal layer 102 by using a sputtering process (not shown). The copper-gallium alloy layer 104 , the indium metal layer 106 and the copper-gallium alloy layer 108 stacked on the molybdenum metal layer 102 serve as a precursor structure 110 for preparing the CIGS compound semiconductor thin film.

Please refer to FIG. 2 , followed by a tempering process (not shown) and a selenization process 112, the copper-gallium alloy layer 104, indium metal layer 106 and copper-gallium alloy layer 108 are alloyed and selenized to form a yellow The copper indium gallium selenide thin film 114 with a chalcopyrite structure.

Adopting the precursor structure of the CIGS compound semiconductor thin film as shown in FIG. 1-2 and the formed CIGS compound thin film 114 have disadvantages such as poor film flatness and inconsistent thickness uniformity. The reason is that the melting point of indium metal in the indium metal layer 106 is 156.6° C., and the sputtering temperature when the indium metal layer 106 is formed by sputtering process is usually about 150-250° C. and higher than the melting point of indium metal. When the indium metal layer 106 is formed by sputtering on the copper-gallium alloy layer 104, the indium metal is formed in a molten state or a semi-molten state, thereby producing granular stacking and making the indium metal film in the indium metal film on the surface of the copper-gallium alloy layer 104 Metal layer 106 produces an uneven surface and uneven thickness, as shown in FIG. 1 . And the indium metal layer 106 with uneven surface and uneven thickness also affects the deposition of the precursor structure 110 including the copper gallium alloy layer 104, the indium metal layer 106 and the copper gallium alloy layer 108, and after the selenization process 112 is performed A CIGS thin film 114 is produced that also has an uneven surface. The CIGS thin film 114 with such an uneven surface and uneven thickness will affect the cell efficiency of the thin film solar cell to which it is applied, and reduce the photoelectric conversion efficiency of the thin film solar cell.

In addition, the structure shown in FIG. 2 also has the following problems. That is, when the selenization process 112 is performed on the structure as shown in FIG. interface. This shows that the molybdenum metal layer 102 and the substrate 100 are often separated from the molybdenum metal layer 102 due to excessive thermal stress during the selenization process. The above thermal stress mainly comes from the difference in thermal expansion coefficient between the molybdenum metal layer 102 and the materials in the substrate 100 such as glass, metal foil and polymer at high temperature. Due to the difference between the coefficient of thermal expansion of the material used for the substrate 100 and the coefficient of thermal expansion of the molybdenum metal layer 102, at a process temperature above 400°C, there will often be a large stress difference caused by the difference in thermal expansion. This phenomenon is also caused by The reason for peeling off between the CIGS thin film 114 /molybdenum metal electrode layer 102 and the substrate 100 occurs.

Contents of the invention

In view of this, the present invention provides a method for fabricating a CIGS thin film to solve the above-mentioned known problems.

According to an embodiment, the present invention provides a method for manufacturing a copper indium gallium selenide compound thin film, comprising: providing a substrate; forming an adhesive layer on the substrate; forming a metal electrode layer on the adhesive layer; forming a precursor Precursor stacked film layer on the metal electrode layer, wherein the precursor stacked film layer includes a plurality of copper-gallium alloy layers and at least one copper-indium alloy layer sandwiched between the copper-gallium alloy layers; performing a tempering process , to convert the precursor stacked film layer into a CIGa alloy layer; and perform a selenization process to convert the CIGa alloy layer into a CIGaSe compound layer.

The invention can improve the surface roughness of the obtained copper gallium indium selenide compound thin film, and improve its battery efficiency and photoelectric conversion efficiency when it is applied in thin film solar cells.

In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is specifically cited below, and in conjunction with the accompanying drawings, the detailed description is as follows:

Description of drawings

Figure 1-2 has shown the manufacturing method of known copper indium gallium selenide compound semiconductor film;

3-5 show a method for manufacturing a copper indium gallium selenide compound semiconductor thin film according to an embodiment of the present invention;

6-7 show a method for manufacturing a copper indium gallium selenide compound semiconductor thin film according to another embodiment of the present invention;

FIG. 8 is a flowchart showing a method for manufacturing a copper indium gallium selenide compound semiconductor thin film according to an embodiment of the present invention;

FIG. 9 is a spectrogram showing the X-ray diffraction analysis results of the CIGS thin film obtained according to an embodiment of the present invention.

[Description of main component symbols]

100～substrate; 102～molybdenum metal layer;

104, 108～copper-gallium alloy layer; 106～copper-gallium alloy layer;

110～Precursor structure; 112～Selenization procedure;

114～copper indium gallium selenide thin film; 200～substrate;

202～adhesive layer; 204～metal electrode layer;

206, 210～copper-gallium alloy layer; 208～copper-indium alloy layer;

212～precursor stacked film layer; 214～tempering procedure;

216～copper indium gallium alloy layer; 218～selenization process;

220～copper indium gallium selenide compound layer; 300～substrate;

302～adhesive layer; 304～metal electrode layer;

306, 310, 314～copper-gallium alloy layer; 308, 312～copper-gallium alloy layer;

316～precursor stacked film layer; 320～copper-gallium alloy layer.

Detailed ways

Embodiments of the present invention will be explained below with reference to FIGS. 3-9 and other drawings.

Please refer to FIGS. 3-5 , which show a method for manufacturing a CIGS thin film according to an embodiment of the present invention.

As shown in FIG. 3 , firstly, a substrate 200 is provided, such as a substrate made of glass, metal foil, or polymer material. Here, the substrate 200 is a substrate that has been cleaned to remove impurities such as oil stains or particles remaining on the surface. Next, an adhesive layer 202 and a metal electrode layer 204 are sequentially formed on the substrate 200 . The adhesive layer 202 is used to improve the thermal expansion coefficient difference between the metal electrode layer 204 and the substrate 200 and enhance the adhesion between the metal electrode layer 204 and the substrate. In one embodiment, the adhesion layer 202 is, for example, a molybdenum metal layer formed on the metal electrode layer 204 by sputtering at a pressure higher than 5 mtorr, and the metal electrode layer 204 is for example by sputtering at a pressure lower than 5 mtorr. A molybdenum metal layer is formed on the adhesive layer 202 under a pressure of 5 mtorr. In this embodiment, the molybdenum metal layer as the adhesive layer 202 is preferably formed on the metal electrode layer 204 under a pressure of 6-8 mtorr. In one embodiment, the thickness of the adhesive layer 202 is about 50-600 nm, and the thickness of the metal electrode layer 204 is about 200-600 nm. The thickness is, for example, a thickness of about 1000 nanometers. In other embodiments, the adhesive layer 202 may contain a metal layer of titanium, tantalum, cobalt, chromium, nickel, tungsten or an alloy thereof, so as to improve the difference in thermal expansion coefficient between the subsequently formed metal electrode layer and the substrate 200, while the metal The electrode layer can be a metal layer containing molybdenum.

Next, a precursor stack film layer 212 is formed on the surface of the metal electrode layer 204 , which includes two copper-gallium alloy layers 206 and 210 and a copper-indium alloy layer 208 sandwiched between the copper-gallium alloy layers 206 and 210 . Here, the copper-gallium alloy layers 206 and 210 and the copper-indium alloy layer 208 in the precursor stack film layer 212 can be formed on the metal electrode layer 204 by methods such as sputtering, evaporation, electroplating, etc. or a combination of the above methods. . In one embodiment, when the copper-gallium alloy layers 206 and 210 and the copper-indium alloy layer 208 in the precursor stack film layer 212 are formed by sputtering, Cu _y Ga _1-y and Cu _x In _1-x can be used. and other targets are used as the material sources of these layers, wherein the gallium content in the Cu _y Ga _1-y alloy target must be less than 78% (y>0.22) and the copper content in the Cu _x In _1-x target must be higher than 4% (x>0.04), in order to keep the target material and the alloy film layer sputtered on the metal electrode layer 204 in a solid state during the sputtering process, so as to facilitate the uniform distribution of the thickness and composition of the stacked film layer of the precursor. Therefore, in this embodiment, the copper-gallium alloy layers 206 and 210 in the precursor stacked film layer 212 obtained by sputtering will have a chemical formula Cu _y Ga _1-y , where 0.22<y<0.9, and the inner The copper-indium alloy layer 208 has a chemical formula _{CuxIn 1-x} , where 0.04<x<0.5. In another embodiment, the copper-gallium alloy layers 206 and 210 have a thickness between 100-600 nm and the copper-indium alloy layer 208 has a thickness between 200-700 nm. As shown in Figure 3, in the precursor stacked film layer 212 at different film thicknesses and depths, the distribution and composition ratio of each metal element can be slightly adjusted to facilitate the reaction with the selenium element to form a selenium-containing compound film, so that the formed The element distribution in different film thickness depths in the compound film will no longer be a single composition distribution as the film thickness changes, and this result helps to obtain the best compound film.

Referring to FIG. 4 , a tempering process 214 is then performed on the structure shown in FIG. 3 to transform the precursor stack film layer into a CIG alloy layer 216 . In one embodiment, the tempering process 214 is performed at a temperature of 150° C.˜400° C. for about 10-80 minutes. In another embodiment, the tempering process 214 is preferably performed at a temperature of about 300° C. and preferably performed for about 40 minutes. The copper indium gallium alloy layer 216 obtained after the tempering process 214 also has a flat film structure with uniform film thickness, and the copper element in the copper indium gallium alloy layer has an element ratio between 0.6˜1.3, The gallium element in the copper indium gallium alloy layer is in an element ratio of 0.1 to 0.5 to ensure the quality of the subsequently formed copper indium gallium selenide compound thin film.

Referring to FIG. 5 , a selenization process 218 is performed on the structure shown in FIG. 4 to convert the CIGa alloy layer 216 into a CIGaSe compound layer 220 . In one embodiment, the selenization process 216 is performed at a temperature of 450° C.˜600° C. and a pressure of 1*10 ⁻⁶ torr˜10 mtorr for about 10-100 minutes. The CIGS compound layer 220 obtained after the selenization process 216 also has a flat film structure with uniform film thickness. In the above-mentioned selenization procedure 216, selenium vapor or ionic selenium such as Se ⁺ and Se ⁺⁺ obtained by plasma dissociation can be used to react with the copper indium gallium alloy layer 216 (see FIG. 4 ), and then the copper indium gallium selenide compound can be obtained Layer 220.

As shown in FIG. 5 , the CIGS compound layer 220 formed on the metal electrode layer 204 has a flat surface and a fairly uniform film thickness. Here, since the copper indium gallium selenide compound layer 220 is a quaternary compound material, gallium and indium elements present different and non-uniform composition distributions in the thickness direction, but the composition distribution on the surface of the copper indium gallium selenide compound layer 220 , gallium, indium elements can show a high degree of uniformity.

In this way, since the CIGS compound layer 220 shown in FIG. 5 has a uniform film thickness, it has a uniform surface composition distribution, and a CIGS compound thin film with uniform film thickness can be produced after the selenization process. In this embodiment, the stacked film layer of copper-gallium alloy layer 206, copper-indium alloy layer 208 and copper-gallium alloy layer 210 is used to replace the known stacked film layer of copper-gallium alloy layer, indium metal layer and copper-gallium alloy layer, so it can be The disadvantages of the precursor thin film produced by the known sputtering process are improved and the efficiency of the finished compound thin film solar cell is improved.

Please refer to FIGS. 6-7 , which show a method for manufacturing a CIGS thin film according to another embodiment of the present invention. This embodiment is obtained by modifying the embodiments shown in FIGS. 3-5 , and only the differences are described here.

As shown in FIG. 6 , a substrate 300 is provided first. Next, an adhesive layer 302 and a metal electrode layer 304 are sequentially formed on the substrate 300 . Next, a precursor stack film layer 316 is formed on the surface of the metal electrode layer 304, which includes three copper gallium alloy layers 306, 310 and 314 and two copper gallium alloy layers sandwiched between these copper gallium alloy layers 306, 310 and 314 respectively. copper indium alloy layers 308 and 312 .

Referring to FIG. 7 , a tempering process and a selenization process (both not shown) are performed on the structure shown in FIG. 6 to form a CIGS compound layer 320 .

In this embodiment, the relevant implementations of the substrate 300 , the adhesive layer 302 and the metal electrode layer 304 are the same as those of the substrate 200 , the adhesive layer 202 and the metal electrode layer 204 in the previous embodiment. In addition, the composition of the precursor stacked film layer 316 in this embodiment has two copper-gallium alloy layers and one copper-indium alloy layer respectively compared with the previous embodiment. These copper-gallium alloy layers 306, 310 and 314 and copper Relevant implementations of the indium alloy layers 308 and 312 are the same as those of the copper-indium alloy layers 206 and 210 and the copper-indium alloy layer 208 in the foregoing embodiments, and the implementation thereof will not be repeated here.

Referring to FIG. 7 , in this embodiment, the CIGS compound layer 320 formed on the metal electrode layer 304 has a flat surface and a fairly uniform film thickness. Here, since the copper indium gallium selenide compound layer 320 is a quaternary compound material, gallium and indium elements present different and non-uniform composition distributions in the thickness direction, but the composition distribution on the surface of the copper indium gallium selenide compound layer 320 , gallium, indium elements can show a high degree of uniformity. In this way, since the CIGS compound layer 320 shown in FIG. 7 has a uniform film thickness, it has a uniform surface composition distribution, and can produce a CIGS compound thin film with uniform film thickness after the selenization process. In this embodiment, three copper-gallium alloy layers 306, 310 and 314 and two copper-indium alloy layers 308 and 312 sandwiched between these copper-gallium alloy layers 306, 310 and 314 are used to replace the stacked film layers of the known The stacked film layers of the copper-gallium alloy layer, the indium metal layer and the copper-gallium alloy layer can improve the defects of the precursor film produced by the known sputtering process and improve the efficiency of the finished compound thin film solar cell.

FIG. 8 is a flowchart showing a method for manufacturing a CIGS compound semiconductor thin film according to an embodiment of the present invention, which reveals the manufacturing process of the embodiment shown in FIGS. 3-5 and 6-7 .

Referring to FIG. 8 , a substrate is provided in step S801 . The substrate is a cleaned substrate to remove oil stains and particles remaining on the surface of the substrate. The method of cleaning the substrate is mainly wet cleaning method, and the cleaning effect can be enhanced by using cleaning agent and ultrasonic vibration, and finally the whole cleaning process is completed by drying procedure. Next, in step S803, the deposition of the metal electrode layer is carried out, which is to put the cleaned substrate into a deposition chamber, and adopt methods such as sputtering, evaporation, electroplating, etc. or a combination of the above methods to sequentially deposit Deposition forms an adhesion layer and a metal electrode layer. Next, in step S805, a precursor stacked film layer is formed on the metal electrode layer by sputtering, vapor deposition, electroplating or a combination thereof. The precursor stacked film layer includes several copper-gallium alloy layers and interposed There is at least one copper-indium alloy layer between the copper-gallium alloy layers. At this time, the precursor stack film layer has a flat surface and a uniform film thickness. Next, in step S807, a tempering process is performed to convert the precursor stack film layer including several copper-indium-gallium alloy layers and at least one copper-indium-alloy layer into a copper-indium-gallium alloy layer. Next, a selenization process is performed in step S807 to convert the obtained CIGa alloy layer into a CIGS compound layer, as shown in step S811 .

Example:

Example 1:

Put a glass substrate in a glass cleaner, and then use an ultrasonic oscillator to accelerate the glass cleaning effect, then put the glass in deionized water (DI water), and rinse it with DI water until there is no cleaning solution left on the glass, then , put the glass in an oven and dry the glass at a temperature of 150°C, put the cleaned glass substrate into the vacuum chamber of the sputtering machine immediately, use the vacuum pump to extract the air and make the pressure of the vacuum chamber lower than 1x10 ^-6 torr , when the pressure value of the vacuum chamber reaches the background pressure, argon gas with a flow rate of 10sccm is introduced to raise the vacuum value of the sputtering chamber to 10mtorr. 400nm first molybdenum thin film, where the first molybdenum thin film has better adhesion to the glass substrate, so the first molybdenum thin film is used as an adhesive layer, but the conductivity of the first molybdenum thin film is poor, and the sheet resistance value is often high At 1ohms/square. Then, improve the pumping efficiency to maintain the vacuum value of the sputtering chamber at 2mtorr, and then use the DC sputtering method to sputter a second molybdenum film above the first molybdenum film. The thickness of the second molybdenum film is 600nm, and the first Molybdenum film has poor adhesion to glass substrates, so it cannot be used as an adhesive layer. The oxygen content of the sputtered molybdenum film can be controlled by changing the sputtering pressure to adjust the physical properties of the first and second molybdenum films. Molybdenum with higher oxygen content and better adhesion can be obtained under higher working pressure Thin films, molybdenum thin films with lower oxygen content are formed under lower working pressure, and have better electrical conductivity (<0.2ohms/square). The completed molybdenum thin film/glass substrate structure remains in the sputtering chamber, and then it is fabricated by DC sputtering as shown in Figure 6. Cu _y Ga _1-y / _Cux In _1-x /Cu _y Ga _1-y / Cu _x In _1-x /Cu _y Ga _1-y stacked film layers. It uses Cu _0.73 Ga _0.27 and Cu _0.48 In _0.52 alloy targets as precursor materials, first sputters a layer of 100nm Cu _0.73 Ga _0.27 alloy film on the molybdenum film/glass substrate structure substrate with a power of 160W, and then reduces the power to 60W, and sputtering a layer of 400nm Cu _0.48 In _0.52 alloy film on the surface of Cu _0.73 Ga _0.27 alloy film, then sputtering a layer of 100nm Cu _0.73 Ga _0.27 alloy film and 400nm Cu _0.48 In _0.52 alloy film, and finally A layer of 150nm Cu _0.73 Ga _0.27 alloy film is sputtered, and the five-layer alternately stacked alloy film forms a Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 stacked structure, which is the precursor for making the copper indium gallium selenide compound layer. The completed five-layer alternately stacked Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 structure can obtain Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stacked film with uniform film thickness, and its thickness is about 1150nm. Then the five layers of Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 stacked layers were taken out, and immediately moved into the selenization furnace, and then 150cc/min of argon gas was introduced to protect the five layers of Cu _0.48 The In _0.52 /Cu _0.73 Ga _0.27 precursor stack film is not oxidized, and the Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stack film is heated at a heating rate of 40°C/min. When the temperature reaches 400°C, the temperature is maintained 60min, so as to convert the precursor stacked film layer into a copper-gallium-indium alloy layer. Then heat the copper-gallium-indium alloy layer to 550°C at a heating rate of 15°C/min, and keep the temperature for 60 minutes. When the above-mentioned temperature rise is carried out, selenium vapor will be generated in the selenization furnace and the selenium vapor will be maintained above the supersaturated vapor pressure , and then perform a selenization process on the copper gallium indium alloy layer and react the copper gallium indium alloy layer with selenium element and convert it into a copper gallium indium selenide compound layer. After the formation of the copper gallium indium selenide compound layer, the temperature is lowered in the selenization furnace to complete the production of the copper gallium indium selenide compound layer.

Then, after X-ray diffraction analysis (XRD) is performed on the copper gallium indium selenide compound layer, the spectrogram and related elemental analysis results shown in FIG. 9 can be obtained. As shown in Figure 9, the formed copper gallium indium selenide compound layer has high crystallinity and belongs to polycrystalline structure, and it has (112), (220/204), (312/116), (400/008) and ( 332/316) crystal plane, which means that this method can produce CuIn _1-x Ga _x Se ₂ film, especially the preferred crystal phase of (112) plane also produces, therefore, the present invention can utilize a Cu _0.48 In _0.52 /Cu _0.73 Ga _{The 0.27} precursor stack film layer is selenized to obtain a copper gallium indium selenide compound layer. This copper indium gallium selenide thin film is a polycrystalline phase. The results of XRD analysis show that it has good crystallinity and can be used as a copper gallium indium selenide compound thin film solar cell. The absorbent layer is used.

Example 2:

Put the glass substrate into the glass cleaner, and use the ultrasonic oscillator to strengthen the glass cleaning effect. After cleaning the glass substrate, immediately put it into deionized water (DI water), and rinse it with DI water until there is no cleaning solution left on the glass , and then put the glass into the oven to dry the glass at a temperature of 150°C, then put the cleaned glass substrate into the vacuum chamber of the sputtering machine, and pump out the air so that the pressure value of the vacuum chamber is lower than 1x10 ^-6 torr, when the pressure value of the vacuum chamber reaches the background pressure, argon gas with a flow rate of 10 sccm is introduced to make the vacuum value of the sputtering chamber rise to 2mtorr, and maintain the vacuum of the sputtering chamber at 2mtorr. At this time, use DC sputtering Plating method, titanium metal is sputtered on the surface of the glass substrate. The thickness of the titanium metal film is 100nm. This layer of titanium metal is an adhesive layer, because titanium and glass have better adhesion; then the molybdenum film is produced under the working pressure of 2mtorr , the thickness of the molybdenum film is 800nm, and the sheet resistance value of the molybdenum film is lower than 0.2ohms/square at this time. When sputtering a titanium metal film on a glass substrate, a molybdenum film and Cu _y Ga _1-y / _Cux In _1-x /Cu _y Ga _1-y stacked structure will be sputtered later, so in order to maintain For the stability between titanium metal and glass, the thickness of titanium metal should be greater than 50nm, and the optimum thickness in this embodiment is 100nm. In addition, those with similar functions to titanium metal, as well as Ta, Cr, Co, Ni, W and other metals or their alloys have better adhesion to glass, and can be used as an adhesive layer between glass substrates and Mo electrodes. The completed titanium and molybdenum film/glass substrate structure remains in the sputtering chamber, and then it is fabricated by DC sputtering as shown in Figure 6 Cu _y Ga _1-y /Cu _x In _1-x /Cu _y Ga _{1- y} /Cu _x In _1-x /Cu _y Ga _1-y stacked film layers. It uses Cu _0.73 Ga _0.27 and Cu _0.48 In _0.52 alloy targets as precursor materials, first sputters a layer of 100nm Cu _0.73 Ga _0.27 alloy film on the titanium and molybdenum film/glass substrate structure substrate with a power of 160W, and then reduces Power to 60W, and sputtering a layer of 400nm Cu _0.48 In _0.52 alloy film on the surface of Cu _0.73 Ga _0.27 alloy film, and then sputtering a layer of 100nm Cu _0.73 Ga _0.27 alloy film and 400nm Cu _0.48 In _0.52 alloy film, Finally, a 150nm layer of Cu _0.73 Ga _0.27 alloy film was sputtered. The five layers of alternately stacked alloy film formed Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 stacked structure, which was the precursor for making the copper indium gallium selenide compound layer. The completed five-layer alternating stacked Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 structure can obtain Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stacked film with uniform film thickness, and its thickness is about 1150nm. Then the five layers of Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 stacked layers were taken out, and immediately moved into the selenization furnace, and then 150cc/min of argon gas was introduced to protect the five layers of Cu _0.48 The In _0.52 /Cu _0.73 Ga _0.27 precursor stack film is not oxidized, and the Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stack film is heated at a heating rate of 40°C/min. When the temperature reaches 350°C, the temperature is kept 60min, so as to convert the precursor stacked film layer into a copper-gallium-indium alloy layer. Then heat the copper-gallium-indium alloy layer to 550°C at a heating rate of 15°C/min, and keep the temperature for 60 minutes. When the above-mentioned temperature rise is carried out, selenium vapor will be generated in the selenization furnace and the selenium vapor will be maintained above the supersaturated vapor pressure. , and then perform a selenization process on the copper gallium indium alloy layer and react the copper gallium indium alloy layer with selenium element and convert it into a copper gallium indium selenide compound layer. After the formation of the copper gallium indium selenide compound layer, the temperature is lowered in the selenization furnace to complete the production of the copper gallium indium selenide compound layer.

Example 3:

With the glass substrate that contains one deck adhesive layer, molybdenum thin film is sputtered on adhesive layer by sputtering mode, and this molybdenum thin film thickness is 600nm, and adhesive layer can be as the first molybdenum thin film, Ti, Ta in embodiment 1. , Cr, Co, Ni and W and other metals or their alloy films. Next, the Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stack film layer shown in Figure 3 is fabricated on the molybdenum film by DC sputtering. This precursor stack film is made of Cu _0.73 Ga _0.27 With Cu _0.48 In _0.52 alloy target as the precursor material, a layer of 100nm Cu _0.73 Ga _0.27 alloy film was sputtered with 160W power on the stacked film layer including molybdenum film and glass substrate, then the power was reduced to 60W, and Sputter a 600nh Cu _0.48 In _0.52 alloy film on the Cu _0.73 Ga _0.27 alloy film surface, and then sputter a 200nm layer of Cu _0.73 Ga _0.27 alloy film. This three-layer alternately stacked alloy film constitutes Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stack film layer, in which the thickness of Cu _0.73 Ga _0.27 alloy film and Cu _0.48 In _0.52 alloy film are 300nm and 600nm respectively. Subsequently, the glass substrate including the completed Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stacked film layer was placed in a vacuum selenization furnace. The pressure value of the selenization furnace is up to 1x10 ^-6 torr, and the glass substrate containing the Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stacked film is heated during the process of extracting the air, and the heating rate is 20°C /min, when the glass substrate and the Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stacked film are heated to 300 °C, the alloy film produces alternate diffusion to promote the formation of the ternary alloy. At this time, the three-layer Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stack film will be transformed into a copper-gallium-indium alloy layer. If the temperature is maintained at 300°C for 30 minutes, Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _{The 0.73} Ga _0.27 precursor stacked thin film was fully mixed. At this time, heat the copper-gallium-indium alloy layer to 520°C, and the heating rate is 25°C/min. When heating, 5 sccm of argon gas is introduced as the carrying gas, and the selenium vapor is taken out of the selenium element by the argon gas for heating. area, so that selenium vapor is introduced into the selenization chamber, and before entering the selenization chamber, it must first pass through a plasma area, using the characteristics of high plasma dissociation rate, to crack the selenium vapor to produce ionic selenium, the ion State selenium can quickly reach the surface of the copper-gallium-indium alloy layer through diffusion, and then diffuse into the interior of the alloy layer from the surface of the alloy layer. After holding the temperature at ℃ for 60 minutes, a complete copper gallium indium selenide compound layer can be obtained. The CuGIS compound layer obtained in this embodiment also has high crystallinity and a chalcopyrite structure. The copper gallium indium selenide compound layer produced by the vacuum selenization process can produce the copper gallium indium selenide compound structure when the selenization temperature is above 480°C. In this embodiment, the selenization temperature should be higher than 520° C., and the selenization holding time should be longer than 30 minutes to ensure the completion of the selenization. The preferred selenization time is 60 minutes. In addition, during the alloying process, the temperature at which the Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 stacked structure is fully mixed should be higher than 200°C. The results of this example show that the better alloying temperature should be At 300°C, and the holding time should be higher than 10min. In this embodiment, referring to the observation of the scanning electron microscope, the surface roughness Ra of the Cu _0.73 Ga _0.27 /Cu _0.48 In _0.52 /Cu _0.73 Ga _0.27 precursor stack film with an overall film thickness of about 800 nm is about 150 nm.

Comparative example 1:

Sputtering a molybdenum thin film on a cleaned glass substrate by means of sputtering, the thickness of the molybdenum thin film is 1000nm. Next, the CuGa/In/CuGa precursor stacked film layer shown in Figure 1 was fabricated on the molybdenum film by DC sputtering. This precursor stacked film uses Cu and Ga alloy targets as precursor materials. A 100nm Cu _0.78 Ga _0.22 alloy film was sputtered at 160W on the stacked film layer including molybdenum film and glass substrate, then the power was reduced to 60W, and a 500nm In metal layer was sputtered on the Cu _0.78 Ga _0.22 alloy film surface, and then sputtered a layer of 300nm Cu _0.78 Ga _0.22 alloy thin film alloy thin film, the three layers of alternately stacked alloy thin film constitute Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 precursor stacked film layer, in which Cu _0.78 Ga _0.22 The thicknesses of the alloy film and the In metal film are 400nm and 500nm, respectively. Subsequently, the glass substrate including the fabricated Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 precursor stacked film layer is placed in a vacuum selenization furnace. The pressure value is up to 1x10 ^-6 torr, and the glass substrate containing the Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 precursor stacked thin film is heated during the process of pumping out the air. The heating rate is 20°C/min. When the glass substrate When the thin film stacked with Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 precursor is heated to 300 °C, the alloy thin film produces alternate diffusion and promotes the formation of ternary alloy. At this time, three layers of Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 The precursor stacked film will be transformed into a copper-gallium-indium alloy layer. If the temperature is maintained at 300° C. for 30 minutes, the Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 precursor stacked film will be fully mixed. Then heat the copper-gallium-indium alloy layer to 550°C at a heating rate of 15°C/min, and keep the temperature for 60 minutes. When the above temperature rise is carried out, selenium vapor is generated in the selenization furnace at the same time and the selenium vapor is kept above the supersaturated vapor pressure. In order to avoid the generation of gaseous selenide, a selenization process is performed on the copper gallium indium alloy layer to react with the selenium element and convert it into a copper gallium indium selenide compound layer. After the formation of the copper gallium indium selenide compound layer, the temperature is lowered in the selenization furnace to complete the production of the copper gallium indium selenide compound layer. In this comparative example, the surface roughness Ra of the Cu _0.78 Ga _0.22 /In/Cu _0.78 Ga _0.22 precursor stack film with an overall film thickness of about 900 nm observed by a scanning electron microscope is about 700 nm.

Referring to the performance of the surface roughness of different precursor stacked films in Comparative Example 1 and Example 3, it can be understood that the manufacturing method of the copper gallium indium selenide compound film provided by the present invention can only produce a film with a surface roughness not higher than 200Ra. The precursor stacks thin films, thus improving the surface roughness of the obtained copper gallium indium selenide compound thin film, and improving its battery efficiency and photoelectric conversion efficiency when it is applied in thin film solar cells.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Any person familiar with the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope defined in the claims.

Claims (22)

1. the manufacture method of a copper-indium-gallium-selenium compound membrane is characterized in that, comprising:

One substrate is provided;

Form an adhesion coating on this substrate;

Form a metal electrode layer on this adhesion coating;

Form a predecessor and pile up rete on this metal electrode layer, wherein this predecessor piles up rete and comprises a plurality of copper gallium alloy layers and be folded at least one copper and indium alloy layer between those copper gallium alloy layers;

Implement a tempering program, to pile up rete be a bronze medal indium gallium alloy layer to transform this predecessor; And

Implementing a selenizing program, is a copper-indium-gallium-selenium compound layer to transform this copper indium gallium alloy layer.

2. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, forms this adhesion coating and comprises a molybdenum layer.

3. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 2 is characterized in that, forms this adhesion coating and is included in formation one molybdenum layer under the pressure of 6～12mtorr.

4. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, forms this adhesion coating and comprises a metal level that forms titaniferous, tantalum, cobalt, chromium, nickel, tungsten or its alloy.

5. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this adhesion coating has the thickness between the 50-600 nanometer.

6. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this adhesion coating and this metal electrode layer have and be not more than one of 1200 nanometers and combine thickness.

7. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, those copper gallium alloy layers that this predecessor piles up in the rete have a chemical formula Cu _yGa _1-y, and 0.22＜y＜0.9.

8. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this at least one copper and indium alloy layer that this predecessor piles up rete has a chemical formula Cu _xIn _1-x, and 0.04＜x＜0.5.

9. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, the copper in this copper indium gallium alloy layer has the element ratio between 0.6～1.3.

10. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, the gallium element in this copper indium gallium alloy layer is between 0.1～0.5 element ratio.

11. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this selenizing program is to implement being higher than under 450 ℃ the temperature.

12. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this selenizing program was implemented about 10～100 minutes.

13. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1, it is characterized in that it is the method for employing sputter, evaporation, plating or its combination and being formed on this metal electrode layer that this predecessor piles up those copper gallium alloy layers and this at least one copper and indium alloy layer in the rete.

14. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this copper-indium-gallium-selenium compound layer has a surface roughness that is not higher than 200Ra.

15. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this selenizing program is to adopt ionic state selenium and copper indium gallium alloy layer to carry out selenylation reaction, to form this copper-indium-gallium-selenium compound layer.

16. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 15 is characterized in that, the plasma selenium of this ionic state selenium for dissociating through plasma.

17. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this selenizing program is to carry out under 450 ℃-600 ℃ temperature.

18. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this selenizing program is between 1*10 ^-6Carry out under the pressure of torr to 10mtorr.

19. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this tempering program is to carry out under a temperature of 150 ℃-400 ℃.

20. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this tempering program was implemented about 10～80 minutes.

21. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this substrate is the substrate through wet-cleaned.

22. the manufacture method of copper-indium-gallium-selenium compound membrane according to claim 1 is characterized in that, this metal electrode layer comprises molybdenum.

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