Method for manufacturing semiconductor package, device for cleaning semiconductor package, and semiconductor package

Abstract

[Problem] To provide a method for manufacturing a semiconductor package including a bonding step for electrically connecting an electrode of a semiconductor chip fixed on a package substrate and an electrode terminal provided on the package substrate. [Solution] A first plasma processing step by hydrogen plasma or water vapor plasma for removing an oxide film on the surface of an electrode of a semiconductor chip and / or an electrode terminal is performed before a bonding step, and a second plasma processing step by inert gas plasma for removing a solder film that is generated in the first plasma processing step is performed after the first plasma processing step.

Description

Method for manufacturing a semiconductor package, cleaning apparatus for a semiconductor package, and semiconductor package

[0001] The present invention relates to a method for manufacturing a semiconductor package including a dry cleaning process for an electrode surface, a cleaning apparatus for a semiconductor package, and a semiconductor package manufactured by this manufacturing method.

[0002] When manufacturing a semiconductor package, a bonding process is performed in which a semiconductor chip is die-bonded to a predetermined position on a package substrate, and the electrodes of the semiconductor chip and the electrode terminals of the package substrate are electrically connected by wire bonding or the like. When this bonding is performed by wire bonding, a cleaning process for removing the oxide film formed on the surface of the electrode is performed before wire bonding. In particular, when the semiconductor chip is a power device, it is very important to ensure the conductivity of the wire bonding portion and to remove the conductive deposits on the surface of the package substrate by such a cleaning process due to the flow of high current.

[0003] As a dry cleaning process for removing the oxide film on the electrode surface of the substrate, a chemically reactive gas plasma process using a reducing gas such as hydrogen gas and a physically reactive sputtering process using an inert gas plasma are known. For example, Patent Document 1 describes a technique for chemically reducing the oxidized portion of an interface by introducing hydrogen-containing plasma to the interface of a semiconductor device, and Patent Document 2 describes a technique for physically removing the oxide film formed on the copper bump and the copper electrode surface by sputtering cleaning with argon atoms.

[0004] Japanese Patent Application Laid-Open No. 2001-093902 Japanese Patent Application Laid-Open No. 2016-201501

[0005] Thus, Patent Document 1 discloses the removal of oxide films by chemical treatment using hydrogen plasma, and Patent Document 2 discloses the removal of oxide films by physical sputtering treatment using argon gas plasma. In these cases, hydrogen plasma treatment is mainly applied as the plasma treatment because it has high selectivity for oxides and can remove oxide films without changing the roughness or shape of the treated surface of the electrodes. On the other hand, when plasma treatment is performed, not only the electrode part to be wire-bonded but also the entire package substrate on which the die-bonded semiconductor chip is mounted is sputtered. Therefore, if the semiconductor chip is die-bonded with solder or if other electronic components are soldered and mixed in, the solder has a low melting point, so when exposed to plasma, evaporation and re-adhesion to the surroundings, a so-called deposition phenomenon, occurs, which is one of the causes of electrode contamination. In physical sputtering using argon gas plasma, the removal rate is greater than the deposition rate of contamination, resulting in no deposition contamination of solder components. However, in chemical processing using hydrogen plasma, the physical removal rate due to collisions with lightweight hydrogen atoms is very small compared to the deposition contamination rate. This leads to evaporation and re-deposition of solder components, which can create unwanted solder films on the package substrate surface and cause malfunctions such as short circuits between electrodes.

[0006] In an attempt to improve the cleaning performance of hydrogen plasma processing, increasing the output of the hydrogen plasma generator made it easier for solder films like these to form, causing short circuits within semiconductor packages. Conversely, attempting to suppress solder film formation prevented improvements in plasma cleaning performance, thus hindering productivity. Furthermore, these solder films were difficult to remove using chemically reactive hydrogen plasma processing.

[0007] Accordingly, the object of the present invention is to provide a semiconductor package manufacturing method, a semiconductor package cleaning apparatus, and a semiconductor package that can effectively achieve both the removal of the oxide film on the electrode by hydrogen plasma treatment and the removal of the solder film that is incidentally generated by the hydrogen plasma treatment.

[0008] The semiconductor package manufacturing method of the present invention includes a bonding step of electrically connecting electrodes of a semiconductor chip fixed to a package substrate with electrode terminals provided on the package substrate. In particular, according to the present invention, a first plasma treatment step using hydrogen plasma or water vapor plasma is performed before the bonding step to remove the oxide film on the surface of the electrodes and / or electrode terminals of the semiconductor chip, and a second plasma treatment step using inert gas plasma is performed after the first plasma treatment step to remove the solder film generated by the first plasma treatment step.

[0009] A first plasma treatment step using hydrogen plasma or water vapor plasma and a second plasma treatment step using inert gas plasma are performed sequentially before the bonding step. As a result, the oxide film on the surface of the semiconductor chip electrode and / or the electrode terminal of the package substrate is removed by the first plasma treatment step, which is a chemical treatment, and after the first plasma treatment step, the solder film generated in the first plasma treatment step is removed by the second plasma treatment step, which is a physical treatment. Thus, according to the present invention, the oxide film is efficiently removed by chemical treatment, and the solder film is efficiently removed by a separate, dedicated physical treatment, enabling effective cleaning with high productivity.

[0010] It is preferable to repeat the first plasma treatment process and the second plasma treatment process multiple times. By repeating the two types of plasma treatment multiple times, even if both plasma treatments are low-power treatments, the oxide film and solder film can be reliably removed, and an efficient cleaning process can be performed.

[0011] Preferably, both the first plasma treatment step and the second plasma treatment step are plasma treatment steps using capacitively coupled plasma (CCP).

[0012] It is also preferable that the first plasma treatment step is an inductively coupled plasma (ICP) plasma treatment step, and the second plasma treatment step is a capacitively coupled plasma (CCP) plasma treatment step. Because the first plasma treatment is an ICP plasma treatment, a very large amount of hydrogen and hydroxyl radicals are generated, and an extremely high reducing effect can be obtained. Due to the high plasma density, sufficient reducing power can be obtained even with water vapor gas.

[0013] It is also preferable that the first plasma treatment step and the second plasma treatment step are steps in which plasma treatment is performed using the same chamber.

[0014] It is also preferable that the first plasma treatment step and the second plasma treatment step are steps in which plasma treatment is performed using different chambers.

[0015] It is also preferable that the first plasma treatment step is a plasma treatment step using hydrogen gas, a mixture of hydrogen gas and an inert gas, or water vapor gas. In this case, the inert gas acts as a carrier gas.

[0016] It is also preferable that the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas containing 50% or more argon gas, or a mixed gas of argon gas and another inert gas. By sputtering with an inert gas containing 50% or more argon gas, it is possible to efficiently remove the solder film generated in the first sputtering treatment step.

[0017] It is also preferable that the first plasma treatment step and the second plasma treatment step are treatment steps using a common gas.

[0018] In this case, it is more preferable that the common gas is a mixture of hydrogen gas and an inert gas, or a mixture of water vapor gas and an inert gas.

[0019] It is also preferable that the first plasma treatment step is a plasma treatment step using hydrogen gas or water vapor gas at a pressure of 50 to 500 Pa, and the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas at a pressure of 5 to 50 Pa. Thus, the gas pressure in the second plasma treatment step is lower than the gas pressure in the first plasma treatment step.

[0020] In this case, the first plasma treatment step has a treatment time of 1 to 5 minutes and an output per unit area of ​​the high-frequency electrode of 0.5 to 1.0 W / cm². ２ Preferably, this is a high-frequency plasma treatment process in which a high frequency of 13.56 MHz is applied.

[0021] It is also preferable that the first plasma treatment step is a plasma treatment step using hydrogen gas or water vapor gas at a pressure of 500 Pa or more, and the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas at a pressure of 100 Pa or less.

[0022] In this case, the second plasma treatment step has a treatment time of 5 to 15 seconds and an output per unit area of ​​the high-frequency electrode of 0.5 to 1.0 W / cm². ２ It is more preferable that the process is a high-frequency sputtering process in which a high frequency of 13.56 MHz is applied. Thus, the processing time of the second plasma processing process is shorter than the processing time of the first plasma processing process.

[0023] It is also preferable that the first plasma treatment step is a plasma treatment step using hydrogen gas or water vapor gas at a pressure of 10 to 50 Pa, and the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas at a pressure of 5 to 50 Pa.

[0024] In this case, it is more preferable that the first plasma treatment step is a high-frequency plasma treatment step in which a high frequency is applied, with a treatment time of 30 to 60 seconds, a total output of 300 W to 1 kW of high-frequency electrodes, and a frequency of 13.56 MHz.

[0025] The present invention further provides a semiconductor package cleaning apparatus manufactured by the above-described semiconductor package manufacturing method, comprising an inductively coupled plasma (ICP) generation unit for generating hydrogen plasma or water vapor plasma for removing oxide films on the surfaces of electrodes and / or electrode terminals of a semiconductor chip, and a capacitively coupled plasma (CCP) generation unit for generating inert gas plasma for removing solder films generated by the hydrogen plasma or water vapor plasma, all within the same chamber.

[0026] A first plasma treatment using hydrogen plasma or water vapor plasma is performed by an ICP generation unit, and a second plasma treatment using inert gas plasma is performed by a CPP generation unit located in the same chamber as the ICP generation unit.

[0027] It is preferable that the ICP generation unit and the CCP generation unit are arranged facing each other in the vertical direction within the chamber described above.

[0028] It is also preferable that the ICP generation unit and the CCP generation unit are provided in parallel to each other at the bottom of the chamber described above.

[0029] The present invention further provides a semiconductor package manufactured by the semiconductor package manufacturing method described above.

[0030] According to the present invention, the oxide film on the surface of the semiconductor chip electrode and / or electrode terminal is removed by a first plasma treatment step, which is a chemical treatment, and after the first plasma treatment step, the solder film generated in the first plasma treatment step is removed by a second plasma treatment step, which is a physical treatment. In this way, the oxide film is efficiently removed by chemical treatment, and the solder film is efficiently removed by a separate, dedicated physical treatment, enabling effective cleaning with high productivity.

[0031] This is a schematic diagram showing an example of the configuration of a plasma cleaning apparatus used in the first embodiment of the semiconductor package manufacturing method of the present invention. This is a flowchart that outlines the flow of the semiconductor package manufacturing process in the first embodiment. This is a schematic diagram that outlines the state of each component in each step of the semiconductor package manufacturing process in the first embodiment. This is an explanatory diagram showing the oxide film to be removed by cleaning in the first embodiment. This is an explanatory diagram showing the solder film to be removed by cleaning in the first embodiment. This is a flowchart that outlines the flow of the semiconductor package manufacturing process in the second embodiment of the semiconductor package manufacturing method of the present invention. This is a schematic diagram showing an example of the configuration of a plasma cleaning apparatus used in the third embodiment of the semiconductor package manufacturing method of the present invention. This is a schematic diagram showing an example of the configuration of a plasma cleaning apparatus used in the fourth embodiment of the semiconductor package manufacturing method of the present invention. This is a schematic diagram showing the plasma cleaning apparatus used in the fourth embodiment with the top cover removed.

[0032] Figure 1 shows an example of the configuration of a plasma cleaning apparatus used in the first embodiment of the semiconductor package manufacturing method of the present invention. In this embodiment, when manufacturing a semiconductor package, a first plasma treatment (first cleaning treatment) is performed to remove the oxide film on the electrodes, and a second plasma treatment (second cleaning treatment) is performed to remove the solder film generated secondarily by the first plasma treatment. In this embodiment, both the first plasma treatment and the second plasma treatment are performed by capacitively coupled plasma (CCP). In this embodiment, the CCP generation unit is configured as a parallel plate type having a cathode electrode and an anode electrode facing each other.

[0033] In Figure 1, 10 is a sealable container (chamber) connected to earth for performing cleaning processing inside, 11 is an inlet located at the top of the chamber 10 for introducing hydrogen gas, a mixture of hydrogen gas and an inert gas, water vapor gas, a mixture of water vapor gas and an inert gas, or other reaction gases into the chamber 10, 12 is a gas supply unit connected to the inlet 11 via an inlet valve 13 and having a variable function for adjusting the mixing ratio of the supplied gases, 14 is an exhaust port located at the bottom of the chamber 10 for exhausting the gas inside the chamber 10, 15 is a pressure pump connected to the exhaust port 14 via an exhaust valve 16 for adjusting the gas pressure inside the chamber 10 by reducing or increasing it, 17 is a cathode electrode that also serves as a support for the object to be cleaned 20, 18 is an anode electrode arranged in parallel opposite to the cathode electrode 17, 19 is a high-frequency power supply connected to the cathode electrode 17, and 21 represents a control device that electrically controls the gas supply unit 12, the inlet valve 13, the pressure pump 15, the exhaust valve 16, and the high-frequency power supply 19. In this embodiment, the object to be cleaned 20 is a package substrate and a semiconductor chip (IC chip) die-bonded onto this package substrate. The object to be cleaned 20 is subjected to a first plasma treatment using hydrogen plasma and a second plasma treatment using inert gas sputtering within the chamber 10.

[0034] Figure 2 schematically shows the flow of the semiconductor package manufacturing process in the first embodiment, and is an example in which the die bonding process is applied as the bonding process for electrical connection. Figure 3 schematically explains the state of each component in each step of the semiconductor package manufacturing process.

[0035] As shown in Figure 2, first, a semiconductor chip is formed from a wafer by dicing, and a package substrate is formed (step S1). As shown in Figure 3(A), a lead frame 23 (corresponding to the electrode terminals of the present invention) is formed on the package substrate 22.

[0036] Next, the semiconductor chip 24 is die-bonded onto the lead frame 23 of the package substrate 22 (step S2). Figure 3(B) shows the state in which a solder layer 25 has been formed on the lead frame 23 of the package substrate 22, and Figure 3(C) shows the state in which the semiconductor chip 24 has been die-bonded onto the solder layer 25. Electrode pads 26 are formed on the surface of this semiconductor chip 24.

[0037] Next, the lead frame 23 and semiconductor chip 24 (the object to be cleaned 20) on the package substrate 22 are subjected to a first plasma treatment using capacitively coupled plasma (CCP) (step S3). In this first plasma treatment, the object to be cleaned 20 is placed on the cathode electrode 17 in the chamber 10 shown in Figure 1, hydrogen gas from the gas supply unit 12 is introduced into the chamber 10 through the introduction hole 11, and a high-frequency voltage is applied to the cathode electrode 17 from the high-frequency power supply 19 to generate hydrogen plasma 27 (see Figure 3(D)) between the cathode electrode 17 and the anode electrode 18. This hydrogen plasma 27 performs a cleaning treatment in which the oxide film on the surface of the lead frame 23 and semiconductor chip 24 of the object to be cleaned 20 is reduced and removed.

[0038] The desirable specific conditions for hydrogen plasma treatment are: hydrogen gas pressure: 50-500 Pa, hydrogen gas flow rate: 50-200 cc / min, high-frequency output: 0.5-1.0 W / cm². ２ (Output per unit area of ​​the high-frequency electrode), High-frequency frequency: 13.56 MHz, Processing time: 1 to 5 minutes. The hydrogen gas pressure is set to a high value to promote the reduction reaction because the reduction process generates many hydrogen radicals. The processing time is set appropriately depending on the thickness of the oxide film to be removed, but is set to about 1 to 5 minutes. In this embodiment, the hydrogen plasma is generated by a high-frequency electric field, but the hydrogen plasma may also be generated by a DC electric field. In addition, the hydrogen gas may be supplied in a state in which the hydrogen gas concentration has been adjusted by mixing it with a noble gas such as helium or argon as a carrier gas.

[0039] FIG. 4 shows the oxide films to be removed on the package substrate 22 and the electrode pads 26 in the first embodiment. FIG. 4(A) is a plan view of the package substrate 22, FIG. 4(B) is a cross-sectional view taken along line A-A of FIG. 4(A), FIG. 4(C) is an enlarged cross-sectional view of a part of the electrode pad 26 on the semiconductor chip 24, and FIG. 4(D) is an enlarged cross-sectional view of a part of the lead frame 23, respectively. As shown in FIG. 4(C), an oxide film 26a exists on the electrode pad 26 of the semiconductor chip 24, and as shown in FIG. 4(D), an oxide film 23a exists on the lead frame 23. These oxide films 26a and 23a are removed by the first plasma treatment.

[0040] Following the first plasma treatment, a second plasma treatment is performed (step S4). The second plasma treatment is a treatment for removing the solder film that has been secondarily deposited on the package substrate 22, the lead frame 23, the semiconductor chip 24, and the electrode pad 26 (the object to be cleaned 20) by the first plasma treatment. In this embodiment, the second plasma treatment is performed using the same chamber 10 as the first plasma treatment as it is.

[0041] In other words, in the second plasma treatment, the package substrate 22, lead frame 23, semiconductor chip 24, and electrode pad 26 (the object to be cleaned 20) are kept in place on the cathode electrode 17 in the chamber 10, the reaction gas used in the first plasma treatment is exhausted to the outside through the exhaust hole 14, and an inert gas is introduced into the chamber 10 from the gas supply unit 12 through the introduction hole 11. Next, an inert gas plasma 28 (see Figure 3(E)) is generated between the cathode electrode 17 and the anode electrode 18 by applying a high-frequency voltage to the cathode electrode 17 from the high-frequency power supply 19. As a result, the solder film deposited on the surfaces of the package substrate 22, lead frame 23, semiconductor chip 24, and electrode pad 26 of the object to be cleaned 20 is physically removed by sputtering with the inert gas plasma 28, thereby performing the cleaning treatment. The inert gas is not particularly limited as long as it can remove the solder film, but from the viewpoint of solder film removal efficiency, a noble gas with an atomic number of 18 (argon) or higher is preferred, and from the viewpoint of cleaning cost, argon gas is desirable. Furthermore, when using argon gas, either 100% argon gas or a mixed inert gas of argon gas and another inert gas (for example, helium gas or neon gas) is used. From the viewpoint of solder film removal efficiency, it is desirable for the mixed inert gas to contain 50% or more argon gas.

[0042] The desired specific conditions for inert gas plasma treatment are: inert gas pressure: 5-50 Pa, inert gas flow rate: 5-20 cc / min, high-frequency output: 0.5-1.0 W / cm². ２ (Output per unit area of ​​the high-frequency electrode), High-frequency frequency: 13.56 MHz, Processing time: 5 to 15 seconds. The inert gas pressure is set to a significantly lower level than in the case of hydrogen gas plasma treatment, to about 5 to 50 Pa, and the processing time is set to a significantly shorter level than in the case of hydrogen gas plasma treatment, to about 5 to 15 seconds.

[0043] FIG. 5 shows the solder films to be removed on the package substrate 22, lead frame 23, semiconductor chip 24, and electrode pads 26 in the first embodiment. FIG. 5(A) is a plan view of the package substrate 22, FIG. 5(B) is a cross-sectional view taken along line B-B of FIG. 5(A), FIG. 5(C) is an enlarged cross-sectional view of a part of the electrode pad 26 on the semiconductor chip 24, and FIG. 5(D) is an enlarged cross-sectional view of a part of the lead frame 23, respectively. As shown in FIG. 5(C), a solder film 26b is deposited on the electrode pad 26 of the semiconductor chip 24 and on the semiconductor chip 24. As shown in FIG. 5(D), a solder film 23b is also deposited on the lead frame 23. These solder films 26b and 23b are removed by sputtering, which is the second cleaning process. In FIG. 5, the solder film 26b is shown in a state of being deposited on the entire electrode pad 26 of the semiconductor chip 24, the semiconductor chip 24, and the lead frame 23. However, since the solder film 26b is likely to occur in a region close to the solder portion of die bonding, it is not necessarily deposited over the entire area.

[0044] As described above, in this embodiment, the first plasma treatment and the second plasma treatment are carried out using the same chamber 10 by switching the gas and changing the plasma treatment conditions. However, the first plasma treatment and the second plasma treatment may be configured to be carried out using different chambers. In that case, the object to be cleaned 20 may be moved by opening each chamber, or each chamber may be hermetically connected by a passage, and configured to move between the chambers non-openly through the passage.

[0045] After the second plasma treatment step is carried out, wire bonding is performed between the lead frame 23 and the electrode pad 26 of the semiconductor chip 24 (step S5 in FIG. 2). As shown in FIG. 3(F), the lead frame 23 and the electrode pad 26 of the semiconductor chip 24 are bonded by a wire 29.

[0046] Subsequently, as shown in Figure 3(G), a coating and curing film 30 is formed to cover a portion of the lead frame 23, the semiconductor chip 24, the electrode pad 26, and the bonding wire 29. Furthermore, as shown in Figure 3(H), the entire package including the coating and curing film 30 is sealed with a molding resin 31 (step S6 in Figure 2).

[0047] As described in detail above, according to the first embodiment, a first plasma treatment using hydrogen plasma is performed before the bonding process, such as the wire bonding process, and then a second plasma treatment using an inert gas is performed. Therefore, first, the oxide film on the surface of the electrode pads 26 and lead frame 23 of the semiconductor chip 24 is chemically removed by the hydrogen plasma treatment, and then the solder film generated by the hydrogen plasma treatment is physically removed by sputtering with the inert gas plasma. Thus, according to this embodiment, the oxide film is efficiently removed by chemical treatment, and the solder film is efficiently removed by a separate, dedicated physical treatment, enabling effective cleaning with high productivity. In addition to the wire bonding method, other known methods such as the flip-chip method can be used for the bonding process.

[0048] In the first embodiment described above, the first plasma treatment and the second plasma treatment are carried out using different types of gases. However, the first plasma treatment and the second plasma treatment may be configured to be carried out using the same common gas. By using the same common gas, gas switching is unnecessary, and the treatment process is greatly simplified. In this case, for example, a mixture of hydrogen gas and an inert gas or a mixture of water vapor gas and an inert gas can be used as the common gas.

[0049] As a modification of the first embodiment, an example of a cleaning process in which the type of gas used is specified and the gas processing pressure is changed will be described below.

[0050] In this modified embodiment, the object to be cleaned 20, which has an oxidized copper electrode and solder material, is placed in the chamber 10. After reducing the pressure inside the chamber 10 to 10 Pa or less while maintaining a high exhaust capacity, a mixed gas of hydrogen gas and helium gas is introduced into the chamber 10 as a first plasma treatment, and high-frequency discharge is performed when the gas pressure is 500 Pa or higher. This generates a large amount of hydrogen radicals, which reduce the copper electrode.

[0051] Next, as a second plasma treatment, argon gas is introduced into the chamber 10 with the exhaust capacity at its maximum, and a high-frequency discharge is performed at a gas pressure of 100 Pa or less. This generates a sputtering effect by heavy argon ions, physically removing inorganic contaminants on the surface (such as solder deposits generated in the first plasma treatment).

[0052] Plasma processing generates ions and highly reactive groups by causing a plasma discharge of gas. In parallel-plate high-frequency plasma processing, which has a simple structure as in this modified embodiment, the pressure required to stably discharge argon gas, which is most commonly used, is about 10 to 100 Pa.

[0053] Hydrogen gas has high reducing properties and is effective in reducing oxidized copper electrodes, but it is also highly explosive. While it is possible to treat with a mixed gas of 96% argon gas and 4% hydrogen gas within the upper limit where explosions do not occur, the amount of hydrogen is 1 / 25th, and energy is consumed in the ionization of the heavier argon gas, resulting in fewer hydrogen reactants and poor reduction efficiency. On the other hand, if helium gas, which has very high discharge stability and can glow discharge up to high pressures, is used as the mixing medium instead of argon gas, stable discharge is possible even at high pressures of about 10 to 10,000 Pa, and by discharging a mixed gas of 96% helium gas and 4% hydrogen gas at high pressure, a very large number of hydrogen reactants can be generated. However, helium gas and hydrogen gas are very light, and compared to argon gas, their ability to physically remove contaminants by sputtering is extremely low, and they have no ability to clean surfaces contaminated by solder deposition during the reduction process. Therefore, as in this modified embodiment, by switching the processing gas and processing pressure, copper electrode reduction with a helium and hydrogen mixed gas in a safe mixing ratio and decontamination with argon gas can be performed continuously, thereby enabling safe and efficient surface treatment (reduction and foreign matter removal) of circuit boards having oxidized copper electrodes and solder material.

[0054] Figure 6 schematically shows the flow of the semiconductor package manufacturing process in a second embodiment of the semiconductor package manufacturing method of the present invention, and is an example in which a die bonding process is applied as the bonding process for electrical connection.

[0055] The configuration of the plasma cleaning apparatus in this embodiment is the same as that shown in Figure 1, so its description will be omitted. Furthermore, the state of each component in each process will be described with reference to Figure 3 in the first embodiment, and the same reference numerals will be used for similar components. The flow of the semiconductor package manufacturing process in this embodiment will now be described in detail with reference to Figure 6.

[0056] As shown in Figure 6, first, a semiconductor chip is formed from a wafer by dicing, and a package substrate is formed (step S11). As shown in Figure 3(A), a lead frame 23 (corresponding to the electrode terminals of the present invention) is formed on the package substrate 22.

[0057] Next, the semiconductor chip 24 is die-bonded onto the lead frame 23 of the package substrate 22 (step S12). Figure 3(B) shows the state in which a solder layer 25 has been formed on the lead frame 23 of the package substrate 22, and Figure 3(C) shows the state in which the semiconductor chip 24 has been die-bonded onto the solder layer 25. Electrode pads 26 are formed on the surface of this semiconductor chip 24.

[0058] Next, the lead frame 23 and semiconductor chip 24 (the object to be cleaned 20) on the package substrate 22 are subjected to a first plasma treatment (step S13). In the first plasma treatment, the object to be cleaned 20 is placed on the cathode electrode 17 in the chamber 10 shown in Figure 1, hydrogen gas from the gas supply unit 12 is introduced into the chamber 10 through the introduction hole 11, and a high-frequency voltage is applied to the cathode electrode 17 from the high-frequency power supply 19 to generate hydrogen plasma between the cathode electrode 17 and the anode electrode 18. This hydrogen plasma 27 performs a cleaning treatment in which the oxide film on the surface of the lead frame 23 and semiconductor chip 24 of the object to be cleaned 20 is reduced and removed.

[0059] The desirable specific conditions for hydrogen plasma treatment are: hydrogen gas pressure: 50-500 Pa, hydrogen gas flow rate: 50-200 cc / min, high-frequency output: 0.5-1.0 W / cm². ２(Output per unit area of ​​the high-frequency electrode), High-frequency frequency: 13.56 MHz, Processing time: 1 to 5 minutes. The hydrogen gas pressure is set to a high value to promote the reduction reaction because the reduction process generates many hydrogen radicals. The processing time is set appropriately depending on the thickness of the oxide film to be removed, but is set to about 1 to 5 minutes. In this embodiment, the hydrogen plasma is generated by a high-frequency electric field, but the hydrogen plasma may also be generated by a DC electric field. In addition, the hydrogen gas may be supplied in a state in which the hydrogen gas concentration has been adjusted by mixing it with a noble gas such as helium or argon as a carrier gas.

[0060] Following the first plasma treatment, a second plasma treatment is performed (step S14). The second plasma treatment is a process to remove the solder film that has been incidentally deposited on the package substrate 22, lead frame 23, semiconductor chip 24, and electrode pad 26 (object to be cleaned 20) by the first plasma treatment. In this embodiment, this second plasma treatment is performed using the same chamber 10 as the first plasma treatment.

[0061] In other words, in the second plasma treatment, the package substrate 22, lead frame 23, semiconductor chip 24, and electrode pad 26 (the object to be cleaned 20) are kept in place on the cathode electrode 17 in the chamber 10, the reaction gas used in the first plasma treatment is exhausted to the outside through the exhaust hole 14, and an inert gas is introduced into the chamber 10 from the gas supply unit 12 through the introduction hole 11. Next, an inert gas plasma 28 (see Figure 3(E)) is generated between the cathode electrode 17 and the anode electrode 18 by applying a high-frequency voltage to the cathode electrode 17 from the high-frequency power supply 19. As a result, the solder film deposited on the surfaces of the package substrate 22, lead frame 23, semiconductor chip 24, and electrode pad 26 of the object to be cleaned 20 is physically removed by sputtering with the inert gas plasma 28, thereby performing cleaning. The inert gas is not particularly limited as long as it can remove the solder film, but from the viewpoint of solder film removal efficiency, a noble gas with an atomic number of 18 (argon) or higher is preferred, and from the viewpoint of cleaning cost, argon gas is desirable. Furthermore, when using argon gas, either 100% argon gas or a mixed inert gas of argon gas and another inert gas (for example, helium gas or neon gas) is used. From the viewpoint of solder film removal efficiency, it is desirable for the mixed inert gas to contain 50% or more argon gas.

[0062] The desired specific conditions for inert gas plasma treatment are: inert gas pressure: 5-50 Pa, inert gas flow rate: 5-20 cc / min, high-frequency output: 0.5-1.0 W / cm². ２ (Output per unit area of ​​the high-frequency electrode), High-frequency frequency: 13.56 MHz, Processing time: 5 to 15 seconds. The inert gas pressure is set to a significantly lower level than in the case of hydrogen gas plasma treatment, to about 5 to 50 Pa, and the processing time is set to a significantly shorter level than in the case of hydrogen gas plasma treatment, to about 5 to 15 seconds.

[0063] As described above, in this embodiment, the first plasma treatment and the second plasma treatment are performed using the same chamber 10, by switching the gas and changing the plasma treatment conditions. However, the first plasma treatment and the second plasma treatment may be configured to be performed using different chambers. In that case, the object to be cleaned 20 may move by opening each chamber, or the chambers may be sealed and connected by a passage, and the object may move between the chambers through that passage.

[0064] After performing the second plasma treatment, it is determined whether the first and second plasma treatments have been repeated N times (step S15). Here, N is an integer of 2 or more. If it is determined in step S15 that the treatment has not been repeated N times (NO), the process returns to step S13, and steps S13 to S15 are repeated. This ensures that the first and second plasma treatments are repeated N times (multiple times). This allows for the intermittent reduction and removal of the oxide film while suppressing the formation of the solder film in the first plasma treatment, and also allows for the removal of the solder film generated each time in the first plasma treatment by the second plasma treatment. As a result, the oxide film and solder film can be reliably removed, enabling an efficient cleaning process.

[0065] In step S15, if it is determined that the process has been repeated N times (YES), wire bonding is performed between the lead frame 23 and the electrode pad 26 of the semiconductor chip 24 (step S16). As shown in Figure 3(F), the lead frame 23 and the electrode pad 26 of the semiconductor chip 24 are bonded together by a wire 29.

[0066] Subsequently, as shown in Figure 3(G), a cured coating film 30 is formed to cover a portion of the lead frame 23, the semiconductor chip 24, the electrode pad 26, and the bonding wire 29. Furthermore, as shown in Figure 3(H), the entire package including the cured coating film 30 is sealed with a molding resin 31 (step S17).

[0067] As described in detail above, according to the second embodiment, a first plasma treatment using hydrogen plasma is performed before a bonding process such as wire bonding, and then a second plasma treatment using an inert gas is performed. Therefore, first, the oxide film on the surface of the electrode pads 26 and lead frame 23 of the semiconductor chip 24 is chemically removed by the hydrogen plasma treatment, and then the solder film generated by the hydrogen plasma treatment is physically removed by sputtering with the inert gas plasma. Thus, according to this embodiment, the oxide film is efficiently removed by chemical treatment, and the solder film is efficiently removed by a separate, dedicated physical treatment, enabling effective cleaning with high productivity. Furthermore, in this embodiment, since the first plasma treatment and the second plasma treatment are repeated multiple times, even if both the first and second plasma treatments are low-power treatments, the oxide film and solder film can be reliably removed, enabling efficient cleaning. In addition to the wire bonding method, known methods such as the flip-chip method can be used for the bonding process.

[0068] In the second embodiment described above, the first plasma treatment and the second plasma treatment are carried out using different types of gases. However, the first plasma treatment and the second plasma treatment may be carried out using the same common gas. By using the same common gas, gas switching is unnecessary, and the treatment process is greatly simplified. In this case, the common gas can be a mixture of hydrogen gas and an inert gas or a mixture of water vapor gas and an inert gas.

[0069] In this embodiment as well, similar to the first embodiment, a modified cleaning process can be applied in which the type of gas used is specified and the gas processing pressure is changed.

[0070] Figure 7 shows an example of the configuration of a plasma cleaning apparatus used in a third embodiment of the semiconductor package manufacturing method of the present invention. In this embodiment, when manufacturing a semiconductor package, a first plasma treatment (first cleaning treatment) is performed to remove the oxide film on the electrodes, and a second plasma treatment (second cleaning treatment) is performed to remove the solder film generated secondarily by the first plasma treatment. In this embodiment, the first plasma treatment is performed by inductively coupled plasma (ICP) from an ICP generation unit, and the second plasma treatment is performed by capacitively coupled plasma (CCP) from a CCP generation unit. As shown in Figure 7, the ICP generation unit and the CCP generation unit are provided in a chamber, facing each other in the vertical direction. In this embodiment, the CCP generation unit is configured as a single-electrode type with a cathode electrode, and the inner wall of the chamber etc. functions as the anode electrode (ground).

[0071] In Figure 7, 110 is a sealed container (chamber) connected to earth for cleaning processing inside, 111 is an inlet located at the top of the chamber 110 for introducing hydrogen gas, a mixture of hydrogen gas and an inert gas, water vapor gas, a mixture of water vapor gas and an inert gas, or other reaction gases into the chamber, 112 is a gas supply unit connected to the inlet 111 via an inlet valve 113 and having a variable function for the mixing ratio of the supplied gases, 114 is an exhaust port located at the bottom of the chamber 110 for exhausting the gas inside the chamber 110, and 115 is an exhaust valve 11 connected to the exhaust port 114 6 is connected to a pressure pump that reduces or increases the gas pressure inside the chamber 110, 117 is a cathode electrode that also serves as a support for the object to be cleaned 120, 119 is a high-frequency power supply connected to the cathode electrode 117, 122 is an ICP generation unit provided in communication with the top of the chamber 110, 123 is an ICP coil provided in the ICP generation unit 122, 124 is a high-frequency power supply connected to the ICP coil 123, and 121 represents a control device that electrically controls the gas supply unit 112, the introduction valve 113, the pressure pump 115, the exhaust valve 116, and the high-frequency power supplies 119 and 124. In this embodiment, the object to be cleaned 120 is a package substrate and a semiconductor chip (IC chip) die-bonded onto this package substrate. The object to be cleaned 120 is subjected to a first plasma treatment using hydrogen plasma generated by ICP and a second plasma treatment using inert gas sputtering generated by CCP within the chamber 110.

[0072] The flow of the semiconductor package manufacturing process in this embodiment is the same as that shown in Figure 2 of the first embodiment, as it is an example in which a die bonding process is applied as the bonding process for electrical connection, so a description will be omitted. Also, the state of each component in each process is the same as that shown in Figure 3 of the first embodiment, so a description will be omitted.

[0073] In this third embodiment, the object to be cleaned 120 is subjected to a first plasma treatment using ICP. Specifically, in this first plasma treatment, the object to be cleaned 120 is placed on a support (cathode electrode) 117 in the chamber 110 shown in Figure 7, hydrogen gas, a mixture of hydrogen gas and an inert gas, or water vapor gas is introduced into the ICP generation unit 122 from the gas supply unit 112 through the introduction hole 111, and a high-frequency voltage is applied to the ICP coil 123 from the high-frequency power supply 124, thereby generating a very large amount of hydrogen radicals by inductive coupling. As a result, the oxide film on the surface of the lead frame and semiconductor chip of the object to be cleaned 120 is reduced and removed with extremely high reducing power. By using ICP in this way, various effects can be obtained, such as a significant increase in radical generation due to the high plasma density, stable operation for a long time is possible, and metal contamination can be reduced because electrodes are not required. In particular, regarding the hydrogen radicalization of water vapor gas, it is very effective because high-density, high-temperature plasma can be stably generated, resulting in high decomposition efficiency.

[0074] The preferred specific conditions for ICP processing are: high frequency: 13.56 MHz, high frequency output: 300 W to 1 kW (total output), gas flow rate: 50 to 500 cc / min, and processing time: 30 to 60 seconds. The high frequency may also be 27 MHz. Within this range of gas flow rate, the gas pressure will be approximately 10 to 50 Pa. The processing time is assumed to be a realistic mass production processing time. Hydrogen gas or water vapor gas may be supplied in a state where the gas concentration has been adjusted by mixing it with a noble gas such as helium or argon as a carrier gas.

[0075] Following the first plasma treatment, a second plasma treatment is performed using a CCP. The second plasma treatment is a process to remove the solder film that was incidentally deposited on the object to be cleaned 120 by the first plasma treatment. In this embodiment, this second plasma treatment is performed using the same chamber 110 as the first plasma treatment.

[0076] In the second plasma treatment, the object to be cleaned 120 remains placed on the cathode electrode 117 inside the chamber 110, the reaction gas used in the first plasma treatment is exhausted to the outside through the exhaust port 114, and an inert gas is introduced into the chamber 110 from the gas supply unit 112 through the introduction port 111. Next, an inert gas plasma is generated by applying a high-frequency voltage to the cathode electrode 117 from the high-frequency power supply 119. As a result, the solder film deposited on the surface of the object to be cleaned 120 is physically removed by sputtering with the inert gas plasma, and the cleaning process is performed. The inert gas is not particularly limited as long as it can remove the solder film, but from the viewpoint of solder film removal efficiency, a noble gas with an atomic number of 18 (argon) or higher is preferred, and from the viewpoint of cleaning cost, argon gas is desirable. When using argon gas, either 100% argon gas or a mixed inert gas of argon gas and other inert gases (e.g., helium gas or neon gas) is used. The mixed inert gas should preferably contain 50% or more argon gas from the viewpoint of solder film removal efficiency.

[0077] The desired specific conditions for inert gas plasma treatment are: inert gas pressure: 5-50 Pa, inert gas flow rate: 5-20 cc / min, high-frequency output: 0.5-1.0 W / cm². ２ (Output per unit area of ​​the high-frequency electrode), High-frequency frequency: 13.56 MHz, Processing time: 5 to 15 seconds. The inert gas pressure is set to approximately 5 to 50 Pa, and the processing time is set to approximately 5 to 15 seconds.

[0078] As described in detail above, according to the third embodiment, a first plasma treatment of hydrogen gas or water vapor gas by ICP is performed before a bonding process such as a wire bonding process, and thereafter, a second plasma treatment of inert gas by CCP is performed. Therefore, first, the oxide film on the surface of the electrode pads and lead frame of the semiconductor chip, which is the object to be cleaned 120, is chemically removed by the hydrogen plasma treatment by ICP, and the solder film generated by the hydrogen plasma treatment is physically removed by sputtering treatment with inert gas plasma by CCP. Thus, according to this embodiment, the oxide film is efficiently removed by chemical treatment (hydrogen plasma treatment), and the solder film is efficiently removed by a separate dedicated physical treatment (sputtering treatment), enabling effective cleaning with high productivity. In particular, in this embodiment, a very large amount of hydrogen radicals is generated by ICP, and the oxide film on the surface of the lead frame and semiconductor chip of the object to be cleaned 120 is reduced and removed with extremely high reducing power. Furthermore, in this embodiment, since the first plasma treatment and the second plasma treatment can be repeated multiple times, even if both the first and second plasma treatments are low-power treatments, the oxide film and solder film can be reliably removed, enabling efficient cleaning. In addition to the wire bonding method, known methods such as the flip-chip method can be used for the bonding process.

[0079] As described above, in this embodiment as well, the first plasma treatment and the second plasma treatment are performed using the same chamber 110, by switching the gas and changing the plasma treatment conditions. However, the first plasma treatment and the second plasma treatment may be configured to be performed using different chambers. In that case, the object to be cleaned 120 may move with each chamber open, or the chambers may be sealed and connected by a passage, and the object may move between the chambers via that passage without opening the chambers.

[0080] In this embodiment, the first plasma treatment and the second plasma treatment are carried out using different types of gases, but the first and second plasma treatments may also be performed using the same common gas. By using the same common gas, gas switching is unnecessary, and the treatment process is greatly simplified. In this case, the common gas can be a mixture of hydrogen gas and an inert gas or a mixture of water vapor gas and an inert gas.

[0081] In this embodiment as well, similar to the modified embodiment of the first embodiment, a modified cleaning process can be applied in which the type of gas used is specified and the gas processing pressure is changed.

[0082] Figure 8 shows an example of the configuration of a plasma cleaning apparatus used in the fourth embodiment of the semiconductor package manufacturing method of the present invention, and Figure 9 shows the plasma cleaning apparatus with the top cover removed. In this embodiment, when manufacturing a semiconductor package, a first plasma treatment (first cleaning treatment) is performed to remove the oxide film on the electrodes, and a second plasma treatment (second cleaning treatment) is performed to remove the solder film generated secondarily by the first plasma treatment. In this embodiment, the first plasma treatment is performed by ICP by an ICP generation unit, and the second plasma treatment is performed by CCP by a CCP generation unit. As shown in Figures 8 and 9, the ICP generation unit and the CCP generation unit are provided in parallel to each other at the bottom of the chamber. In this embodiment, the CCP generation unit is configured as a single-electrode type with a cathode electrode and the inner wall of the chamber etc. functioning as an anode electrode (ground).

[0083] In Figures 8 and 9, 210 is a sealed container (chamber) connected to earth for performing cleaning processing inside, 210a is the top lid of the chamber 210, 211 is an inlet at the bottom of the chamber 210 for introducing ICP gas into the chamber 210, such as hydrogen gas, a mixture of hydrogen gas and an inert gas, water vapor gas, a mixture of water vapor gas and an inert gas, or other reaction gases, 212 is an ICP gas supply unit connected to the inlet 211 via an inlet valve 213 and having a variable function for adjusting the mixing ratio of the supplied ICP gas, 214 is an exhaust port at the bottom of the chamber 210 in parallel with the ICP generation unit 222 for exhausting the gas inside the chamber 210, 215 is a pressure pump connected to the exhaust port 214 via an exhaust valve 216 for adjusting the gas pressure inside the chamber 210 by reducing or increasing it, 217 is a cathode electrode that also serves as a support for the object to be cleaned 220, and 219 is a high-frequency power supply connected to the cathode electrode 217 ,222 is an ICP generator provided in parallel with the CCP generator at the bottom of the chamber 210, 223 is an ICP coil provided in the ICP generator 222, 224 is a high-frequency power supply connected to the ICP coil 223, 225 is an introduction hole provided on the side of the chamber 210 for introducing CCP gas, 227 is a CCP gas supply unit connected to the introduction hole 225 via an introduction valve 226 and having a variable function for the mixing ratio of the supplied CCP gas, 228 is provided on the side of the chamber 210 An introduction hole 230 for introducing downstream gas into the chamber 210 is connected to the introduction hole 228 via an introduction valve 229, and a downstream gas supply unit 221 for supplying downstream gas is represented, along with a control device that electrically controls the ICP gas supply unit 212, the CCP gas supply unit 227, the downstream gas supply unit 230, introduction valves 213, 226 and 229, the pressure pump 215, the exhaust valve 216, and the high-frequency power supplies 219 and 224. In this embodiment, the object to be cleaned 220 is a package substrate and a semiconductor chip (IC chip) die-bonded onto this package substrate.The object to be cleaned 220 is subjected to a first plasma treatment in the chamber 210 using hydrogen plasma or water vapor plasma generated by ICP, and a second plasma treatment using inert gas sputtering generated by CCP. In the first plasma treatment, since the hydrogen radicals generated by ICP are highly diffusive, the supply of downstream gas should be performed as needed.

[0084] The flow of the semiconductor package manufacturing process in this embodiment is the same as that shown in Figure 2 of the first embodiment, as it is an example in which a die bonding process is applied as the bonding process for electrical connection, so a description will be omitted. Also, the state of each component in each process is the same as that shown in Figure 3 of the first embodiment, so a description will be omitted.

[0085] In this fourth embodiment, the object to be cleaned 220 is subjected to a first plasma treatment using ICP. Specifically, in this first plasma treatment, the object to be cleaned 220 is placed on the cathode electrode 217 in the chamber 210 shown in Figures 8 and 9, hydrogen gas, a mixture of hydrogen gas and an inert gas, or water vapor gas is introduced from the ICP gas supply unit 212 into the ICP generation unit 222 of the chamber 210 through the introduction hole 211, and a high-frequency voltage is applied from the high-frequency power supply 224 to the ICP coil 223, thereby generating a very large amount of hydrogen radicals by inductive coupling, and the oxide film on the surface of the lead frame and semiconductor chip of the object to be cleaned 220 is reduced and removed with extremely high reducing power. By using ICP in this way, various effects can be obtained, such as a significant increase in the amount of radicals generated due to the high plasma density, stable operation for a long time is possible, and metal contamination can be reduced because electrodes are not required. In particular, regarding the hydrogen radicalization of water vapor gas, it is very effective because a high-density, high-temperature plasma can be stably generated, resulting in high decomposition efficiency.

[0086] The preferred specific conditions for ICP processing are: high frequency: 13.56 MHz, high frequency output: 300 W to 1 kW (total output), gas flow rate: 50 to 500 cc / min, and processing time: 30 to 60 seconds. The high frequency may also be 27 MHz. Within this range of gas flow rate, the gas pressure will be approximately 10 to 50 Pa. The processing time is assumed to be a realistic mass production processing time. Hydrogen gas or water vapor gas may be supplied in a state where the gas concentration has been adjusted by mixing it with a noble gas such as helium or argon as a carrier gas.

[0087] Following the first plasma treatment, a second plasma treatment is performed using a CCP. The second plasma treatment is a process to remove the solder film that was incidentally deposited on the object to be cleaned 220 by the first plasma treatment. In this embodiment, this second plasma treatment is performed using the same chamber 210 as the first plasma treatment.

[0088] In the second plasma treatment, the object to be cleaned 220 remains placed on the cathode electrode 217 inside the chamber 210, the reaction gas used in the first plasma treatment is exhausted to the outside through the exhaust port 214, and an inert gas is introduced into the chamber 210 from the CCP gas supply unit 212 through the introduction port 225. Next, an inert gas plasma is generated by applying a high-frequency voltage to the cathode electrode 217 from the high-frequency power supply 219. As a result, the solder film deposited on the surface of the object to be cleaned 220 is physically removed by sputtering with the inert gas plasma, and the cleaning treatment is performed. The inert gas is not particularly limited as long as it can remove the solder film, but from the viewpoint of solder film removal efficiency, a noble gas with an atomic number of 18 (argon) or higher is preferred, and from the viewpoint of cleaning cost, argon gas is desirable. When using argon gas, either 100% argon gas or a mixed inert gas of argon gas and other inert gases (e.g., helium gas or neon gas) is used. The mixed inert gas should preferably contain 50% or more argon gas from the viewpoint of solder film removal efficiency.

[0089] The desired specific conditions for inert gas plasma treatment are: inert gas pressure: 5-50 Pa, inert gas flow rate: 5-20 cc / min, high-frequency output: 0.5-1.0 W / cm². ２ (Output per unit area of ​​the high-frequency electrode), High-frequency frequency: 13.56 MHz, Processing time: 5 to 15 seconds. The inert gas pressure is set to approximately 5 to 50 Pa, and the processing time is set to approximately 5 to 15 seconds.

[0090] In this embodiment, the ICP generation unit and the CCP generation unit are arranged in parallel to each other at the bottom of the chamber 210, and an openable and closable top cover 210a is provided on the top surface of the chamber 210. Therefore, during maintenance or when the object to be cleaned 220 is automatically transported, the top cover 210a can be opened as shown in Figure 9 to easily perform these processes. Furthermore, since both the ICP generation unit and the CCP generation unit are located at the bottom of the chamber 210, the center of gravity of the device is lowered, and high-frequency generating components and power supplies can be concentrated at the bottom of the device. As a result, operator safety and EMC (electromagnetic interference) countermeasures become much easier.

[0091] As described in detail above, according to the fourth embodiment, a first plasma treatment of hydrogen gas or water vapor gas by ICP is performed before the bonding process such as the wire bonding process, and thereafter, a second plasma treatment of inert gas by CCP is performed. Therefore, first, the oxide film on the surface of the electrode pads and lead frame of the semiconductor chip, which is the object to be cleaned 220, is chemically removed by the hydrogen plasma treatment, and the solder film generated by the hydrogen plasma treatment is physically removed by sputtering with inert gas plasma. Thus, according to this embodiment, the oxide film is efficiently removed by chemical treatment (hydrogen plasma treatment), and the solder film is efficiently removed by a separate dedicated physical treatment (sputtering treatment), enabling effective cleaning with high productivity. In addition to the wire bonding method, known methods such as the flip-chip method can be used for the bonding process. Furthermore, in this embodiment, a very large amount of hydrogen radicals are generated by ICP, and the oxide film on the surface of the lead frame and semiconductor chip of the object to be cleaned 220 is reduced and removed with extremely high reducing power. Furthermore, in this embodiment, since the first plasma treatment and the second plasma treatment can be repeated multiple times, even if both the first and second plasma treatments are low-power treatments, the oxide film and solder film can be reliably removed, enabling efficient cleaning. In particular, in this embodiment, since the ICP generation unit and the CCP generation unit are arranged in parallel to each other at the bottom of the chamber 210, the center of gravity of the device is lowered, and high-frequency generating components and power supplies can be concentrated at the bottom of the device. As a result, operator safety and EMC (electromagnetic interference) countermeasures become very easy. In addition, since an openable and closable top cover 210a is provided on the top surface of the chamber 210, maintenance and automatic transport of the object to be cleaned 220 can be easily performed by opening the top cover 210a.

[0092] As described above, in this embodiment as well, the first plasma treatment and the second plasma treatment are performed using the same chamber 210, by switching the gas and changing the plasma treatment conditions. However, the first plasma treatment and the second plasma treatment may be configured to be performed using different chambers. In that case, the object to be cleaned 220 may move with each chamber open, or the chambers may be sealed and connected by a passage, and the object may move between the chambers via that passage without opening the chambers.

[0093] In this embodiment, the first plasma treatment and the second plasma treatment are carried out using different types of gases, but the first and second plasma treatments may also be performed using the same common gas. By using the same common gas, gas switching is unnecessary, and the treatment process is greatly simplified. In this case, the common gas can be a mixture of hydrogen gas and an inert gas or a mixture of water vapor gas and an inert gas.

[0094] In this embodiment as well, similar to the modified embodiment of the first embodiment, a modified cleaning process can be applied in which the type of gas used is specified and the gas processing pressure is changed.

[0095] The embodiments described above are all illustrative and not limiting, and the present invention can be implemented in various other variations and modifications. Accordingly, the scope of the present invention is defined solely by the claims and their equivalents.

[0096] 10, 110, 210 Container (chamber) 210a Top lid 11, 111, 211, 225, 228 Inlet holes 12, 112 Gas supply section 13, 113, 213, 226, 229 Inlet valve 14, 114, 214 Exhaust holes 15, 115, 215 Pressure pump 16, 116, 216 Exhaust valve 17, 117, 217 Cathode electrode 18 Anode electrode 19, 119, 219, 224 High-frequency power supply 20, 120, 124, 220 Item to be cleaned 21, 121, 221 Control device 22 Package substrate 23 Lead frame 23a, 26a Oxide film 23b, 26b Solder film 24 Semiconductor chip 25 Solder layer 26 Electrode pad 27 Hydrogen plasma 28 Inert gas plasma 29 Wire 30 Cured coating film 31 Mold resin 122, 222 ICP generation unit 123, 223 ICP coil 212 ICP gas supply unit 227 CCP gas supply unit 230 Downstream gas supply unit

Claims

1. A method for manufacturing a semiconductor package, comprising a bonding step of electrically connecting electrodes of a semiconductor chip fixed to a package substrate and electrode terminals provided on the package substrate, characterized in that, prior to the bonding step, a first plasma treatment step is performed using hydrogen plasma or water vapor plasma to remove an oxide film from the surface of the electrodes of the semiconductor chip and / or the electrode terminals, and, after the first plasma treatment step, a second plasma treatment step is performed using inert gas plasma to remove the solder film generated by the first plasma treatment step.

2. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step and the second plasma treatment step are repeated multiple times.

3. The method for manufacturing a semiconductor package according to claim 1, characterized in that both the first plasma treatment step and the second plasma treatment step are plasma treatment steps using capacitively coupled plasma.

4. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step is a plasma treatment step using inductively coupled plasma, and the second plasma treatment step is a plasma treatment step using capacitively coupled plasma.

5. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step and the second plasma treatment step are steps in which plasma treatment is performed using the same chamber.

6. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step and the second plasma treatment step are steps in which plasma treatment is performed using different chambers.

7. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step is a plasma treatment step using hydrogen gas, a mixture of hydrogen gas and an inert gas, or water vapor gas.

8. The method for manufacturing a semiconductor package according to claim 7, characterized in that the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas containing 50% or more argon gas, or a mixed gas of argon gas and another inert gas.

9. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step and the second plasma treatment step are treatment steps using a common gas.

10. The method for manufacturing a semiconductor package according to claim 9, characterized in that the common gas is a mixture of hydrogen gas and an inert gas or a mixture of water vapor gas and an inert gas.

11. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step is a plasma treatment step using hydrogen gas or water vapor gas at a pressure of 50 to 500 Pa, and the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas at a pressure of 5 to 50 Pa.

12. The first plasma treatment step has a treatment time of 1 to 5 minutes and an output per unit area of ​​the high-frequency electrode of 0.5 to 1.0 W / cm². ２ The method for manufacturing a semiconductor package according to claim 11, characterized in that it is a high-frequency plasma processing step in which a high frequency of 13.56 MHz is applied.

13. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step is a plasma treatment step using hydrogen gas or water vapor gas at a pressure of 500 Pa or more, and the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas at a pressure of 100 Pa or less.

14. The second plasma treatment step has a treatment time of 5 to 15 seconds and an output per unit area of ​​the high-frequency electrode of 0.5 to 1.0 W / cm². ２ The method for manufacturing a semiconductor package according to claim 13, characterized in that it is a high-frequency sputtering process in which a high frequency of 13.56 MHz is applied.

15. The method for manufacturing a semiconductor package according to claim 1, characterized in that the first plasma treatment step is a plasma treatment step using hydrogen gas or water vapor gas at a pressure of 10 to 50 Pa, and the second plasma treatment step is a high-frequency sputtering treatment step using an inert gas at a pressure of 5 to 50 Pa.

16. The method for manufacturing a semiconductor package according to claim 15, characterized in that the first plasma treatment step is a high-frequency plasma treatment step in which the treatment time is 30 to 60 seconds, the total output of the high-frequency electrodes is 300 W to 1 kW, and a high frequency of 13.56 MHz is applied.

17. A semiconductor package cleaning apparatus manufactured by a semiconductor package manufacturing method described in any one of claims 1 to 16, characterized in that it comprises inductively coupled plasma generation unit for generating hydrogen plasma or water vapor plasma for removing oxide films on the surfaces of electrodes and / or electrode terminals of a semiconductor chip, and capacitively coupled plasma generation unit for generating inert gas plasma for removing solder films generated by the hydrogen plasma or water vapor plasma, all within the same chamber.

18. The semiconductor package cleaning apparatus according to claim 17, characterized in that the inductively coupled plasma generation unit and the capacitively coupled plasma generation unit are provided facing each other in the vertical direction within the chamber.

19. The semiconductor package cleaning apparatus according to claim 17, characterized in that the inductively coupled plasma generation unit and the capacitively coupled plasma generation unit are provided in parallel with each other at the bottom of the chamber.

20. A semiconductor package manufactured by the semiconductor package manufacturing method described in any one of claims 1 to 16.

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