TWI576943B - Method for processing power diode - Google Patents

Description

Power diode device processing method

The present invention relates to a cleaning technique for a semiconductor device, and more particularly to a method for processing a power diode device which can greatly improve the effect of cleaning particles.

A power diode is a widely used electronic component and is also one of the important building blocks of an electronic circuit; in general, a good power diode must have both low on-voltage, high switching speed, and high breakdown. Characteristics such as voltage, and the cleanliness of the power diodes usually have a considerable adverse effect on these characteristics.

The main sources of pollution affecting the electrical characteristics of the power diode are dust in the air, flying dust caused by the operation of the operator and the machine, and dry etching residues (such as carbon, metals, oxides, etc.); In the deep sub-micron process, the surface treatment steps after dry etching or etching require deionized water or a highly volatile solvent to clean the process semi-finished product to avoid contamination of the power diode.

At present, the commonly used cleaning techniques such as immersing the process semi-finished product in a high volatility solvent and supplemented by ultrasonic oscillating cleaning method cannot effectively clean the particulate pollution generated in the process, thereby failing to improve the product yield.

Taking a power diode component of a press-fit rectifier diode as an example, the method includes a lead, a pedestal, and a semiconductor wafer between the lead and the pedestal, and the three are soldered together to form a power diode semi-finished product. The side phase exposed surface of the PN junction of the semiconductor wafer needs to be cleaned to improve the withstand voltage capability of the wafer and reduce leakage flow. At present, the common cleaning methods are dry etching and wet etching. Although the dry etching has the advantages of smoother etching line and lower process complexity than wet etching, the residue after dry etching is for the power diode component. Electrical influence is enormous.

The invention aims to prevent the occurrence of secondary pollution, and the main object thereof is to provide a processing method of a power diode device, which can greatly improve the effect of particle cleaning, and can contaminate particles of different particle sizes from the power diode. Physically removed.

To achieve the above object, the present invention adopts the following technical solution: a method for processing a power diode device, comprising the steps of: firstly providing at least one power diode device semi-finished product after dry etching; and then, after dry etching At least one of the power diode device semi-finished products is placed in a high volatility solvent, and a double-frequency ultrasonic oscillating cleaning step is performed to remove at least one of the power diode device semi-finished products after dry etching. Residual dry-etched contaminants; then, at least one of the power diode device semi-finished products after the double-frequency ultrasonic vibration cleaning is subjected to a second cleaning step.

The present invention also provides a processing device for a power diode device for processing a dry etched at least one power diode device semi-finished product, wherein the processing device of the power diode device comprises a dual frequency super device Sound wave cleaning device and a flushing device. The dual-frequency ultrasonic cleaning device is configured to perform a double-frequency ultrasonic oscillating cleaning on at least one of the power diode device semi-finished products after dry etching to remove at least one of the power diodes after dry etching. a dry etching contaminant remaining on the semi-finished product of the body device; the flushing device is located adjacent to the dual-frequency ultrasonic cleaning device for at least one of the power diodes after being oscillated by the double-frequency ultrasonic wave The body device semi-finished product is subjected to a rinsing step.

Compared with the prior art, the present invention has obvious advantages and beneficial effects: the present invention utilizes a dual-frequency ultrasonic oscillator to apply a high-frequency ultrasonic wave and a low-frequency ultrasonic wave to a high-volatility solvent, thereby transmitting high-frequency and low-frequency ultrasonic waves in a solvent. Cavitation effect Various contaminants (especially granular contaminants of different particle sizes) are effectively washed away from the semi-finished products of the power diode device.

Furthermore, the present invention can further utilize the rinsing device to spray a high volatility solvent on the semi-finished product of the power diode device, and can completely remove the contamination due to immersion, so that the dry etched power diode has a good structure. Sex and better electrical properties.

Other objects and advantages of the present invention will be further understood from the technical features disclosed herein. The above and other objects, features, and advantages of the present invention will be apparent from

A‧‧‧Processing equipment

100‧‧‧Double frequency ultrasonic cleaning device

102‧‧‧Solvent storage tank

104‧‧‧Double-frequency ultrasonic oscillator

200‧‧‧ flushing device

202‧‧‧ rinse tank

204‧‧‧Spray mechanism

2042‧‧‧Pressure motor

2044‧‧‧Water supply pipe

2046‧‧‧Spray head

206‧‧‧Solvent supply end

300‧‧‧ dry etching device

302‧‧‧ Plasma generator

304‧‧‧Reaction room

306‧‧‧ bearing seat

308‧‧‧shading board

310‧‧‧Air supply pipe

400‧‧‧Drying device

500‧‧‧Power diode device semi-finished products

502‧‧‧Top wire

504‧‧‧Semiconductor wafer

506‧‧‧Base

508‧‧‧welding layer

510‧‧‧ Guard

Step S100 to step S106

1 is a block diagram of a processing apparatus of a power diode device of the present invention.

2 is a schematic diagram of a conventional dry etching apparatus and a semi-finished product including a power diode.

3 is a schematic view of a dual-frequency ultrasonic cleaning device of the present invention.

Figure 4 is a schematic illustration of the rinsing apparatus of the present invention.

5 is a flow chart of a method of processing a power diode device of the present invention.

Since the dry etching has the advantages of flat etching line and low process complexity compared with the wet etching, the power diode according to the dry etching has good structure and better electrical properties, so as to further improve the power. The product yield and electrical performance of the diode after dry etching, the present invention discloses that "the first use of the dual-frequency ultrasonic oscillating cleaning step removes most of the particulate contamination from the surface of the power diode, and then cooperates The spray rinsing step is a technical means of completely removing the particulate contamination that may be immersed in the immersion to prevent secondary pollution.

The specific embodiments of the above technical means of the present invention are described in conjunction with the accompanying drawings, and the advantages and functions of the present invention can be understood by those skilled in the art from the disclosure. In addition, the present invention may be embodied or applied by other different embodiments, that is, the details in the present specification. The various modifications and changes can be made in the spirit of the invention based on the various aspects and applications. In addition, the drawings are only for the purpose of simplicity of illustration and are not intended to depict the actual dimensions.

1 is a block diagram of a processing device of a power diode device according to a preferred embodiment of the present invention. As shown in the figure, the processing device A provided by the preferred embodiment includes a dual-frequency ultrasonic cleaning device 100 and a flushing device 200 located at adjacent positions; and in practical applications, the processing device A can be combined with a The dry etching apparatus 300 and a drying apparatus 400 are used in combination.

First of all, it should be noted that the processing device A is mainly used for cleaning the dry etching contaminants (or dry etching residues, such as film, dots or particles) remaining on the dry-processed power diode device semi-finished products. Shaped pollution). As shown in FIG. 2, a conventional dry etching apparatus 300 includes a plasma generator 302, a reaction chamber 304, a carrier 306, and a shielding plate 308. The plasma generator 302 is connected to the plasma generator 310 via a gas supply pipe 310. The reaction chamber 304 is connected, and the carrier 306 is disposed in the reaction chamber 304. A power diode assembly semi-finished product 500 is disposed on the carrier 306. The shielding plate 308 is disposed in the reaction chamber 304 and is opposite to the air supply tube 310 for improvement. The concentration distribution of the etching gas within the reaction chamber 304.

Referring to FIG. 2, the power diode device semi-finished product 500 fabricated by the dry etching apparatus 300 mainly includes a top wire 502, a semiconductor wafer 504, and a pedestal 506; wherein the top wire 502 is permeable to a solder layer. 508 is coupled to semiconductor wafer 504, which is also connectable to pedestal 506 via a solder layer 508, which is simultaneously surrounded by a shield 510 of pedestal 506.

It should be further noted that when the dry etching apparatus 300 etches the lateral exposed surface of the PN junction of the semiconductor wafer 504 of the power semiconductor device semi-finished product, the power of the dry etching is generated due to the dry etching. The polar device semi-finished product needs to be transported to the processing device A and sequentially subjected to a dual-frequency ultrasonic oscillating cleaning step and a rinsing step, wherein the dual-frequency ultrasonic oscillating cleaning step removes contaminants from the power diode surface. And the rinsing step prevents secondary pollution After that, the secondary device of the secondary power device after the second cleaning is dried by the drying device 400. It should be understood by those skilled in the art that the above description is only a typical implementation of the processing device A, and subsequent applications of the present invention may have various changes in different implementations.

Please refer to FIG. 3 , which is a schematic diagram of a dual-frequency ultrasonic cleaning device according to a preferred embodiment of the present invention. The dual-frequency ultrasonic cleaning device 100 includes a solvent storage tank 102 and a dual-frequency ultrasonic oscillator 104. In this embodiment, the solvent storage tank 102 can be a cubic tank and can be made of corrosion-resistant materials (such as stainless steel, Made of aluminum or quartz; the solvent storage tank 102 contains a high volatility solvent in actual use, which may be, but not limited to, methanol, ethanol, isopropanol (IPA) or acetone, among which Propanol is the best.

The dual-frequency ultrasonic oscillator 104 is disposed below or around the solvent storage tank 102; it is noted that the dual-frequency ultrasonic oscillator 104 can simultaneously or alternately apply a high frequency ultrasonic wave and a low frequency ultrasonic wave to the highly volatile solvent. At the same time, various contaminants (especially granular contaminants of different particle sizes) are effectively carried away from the surface of the semi-finished product of the power diode device by the cavitation effect of the high-frequency and low-frequency ultrasonic waves in the solvent. For example, the frequency range of the applied high-frequency ultrasonic waves is between about 80 and 150 KHz, and the frequency range of the low-frequency ultrasonic waves is less than 50 KHz, for example, between 30 and 50 KHz, and the oscillation time is about 40 to 120 seconds. Can remove the dry etching contaminants. The above description is only a preferred embodiment of the dual-frequency ultrasonic cleaning device 100. The present invention does not limit the structural composition, form and external dimensions of the dual-frequency ultrasonic cleaning device 100.

In fact, those skilled in the art can achieve the best according to the particle size range of the pollutants to be removed or the residue after dry etching, corresponding to the oscillation frequency of the high frequency ultrasonic wave and the low frequency ultrasonic wave during the dual frequency ultrasonic cleaning. The cleaning effect is not limited by the exemplary high frequency ultrasonic and low frequency ultrasonic ranges proposed by the present invention.

Please refer to FIG. 4, which is a schematic diagram of a rinsing apparatus according to a preferred embodiment of the present invention. The rinsing device 200 includes a rinsing tank 202 and a sprayer disposed on the rinsing tank 202. In this embodiment, the spray mechanism 204 includes a pressurizing motor 2042, a water supply pipe 2044, and a plurality of spray heads 2046. The pressurizing motor 2042 is disposed above the flushing tank 202, and the water supply pipe 2044 is along the top of the flushing tank 202. The wall is horizontally disposed, and one of the free ends of the water supply pipe 2044 is connected to a solvent supply end 206 via a pressurizing motor 2042, and a plurality of sprinkler heads 2046 are spaced apart along the length of the water supply pipe 2044. The above description is only a preferred embodiment of the flushing device 200, and the present invention does not limit the structural composition, form and outer dimensions of the flushing device 200.

When the rinsing device 200 is in actual use, the solvent supply end 206 can continuously supply a highly volatile solvent, which can be, but is not limited to, methanol, ethanol, isopropanol (IPA) or acetone, wherein the same is isopropyl. Alcohol is the best. It should be noted that the high-frequency solvent used by the dual-frequency ultrasonic oscillator 104 and the flushing device 200 may be the same or different, and the invention is not limited thereto.

It is further worth noting that the power diode device semi-finished product 500 can be further transported to the rinsing tank 202 after being immersed in a highly volatile solvent and washed by double-frequency ultrasonic oscillating, and then another high volatility by the pressurizing motor 2042. The solvent is introduced into the water supply pipe 2044, and the contamination that is applied back to the surface of the power diode device semi-finished product 500 is completely removed by spraying, thereby preventing secondary pollution. The idealized condition is that the rinsing time takes about 40 to 120 seconds to take away the contaminants that have been immersed in the immersion.

Furthermore, the power diode device semi-finished product 500 after rinsing (second cleaning) can be sufficiently dried at room temperature, but the basic drying time is relatively long; and considering the overall process rate, the rinsed power can be The diode device semi-finished product 500 is placed in the drying device 400, and the drying temperature is preferably controlled within a range of 50 ° C to 150 ° C to completely evaporate the highly volatile solvent remaining on the surface of the power diode device semi-finished product 500. The dried power diode device semi-finished product 500 can be subjected to the next process.

During the actual equipment/process design, the dual-frequency ultrasonic cleaning device 100, the flushing device 200, and the drying device 400 can be a one-stop production line, that is, the operating time of each device is set to the same setting, such as 40 to 120 seconds.

Referring to FIG. 1 to FIG. 5 together, the constituent unit of the processing device A of the power diode device of the present invention, its technical features and the achieved effects have been described in detail above, and the following further describes the processing device A according to the processing device A. The processing method of the power diode device. As shown in FIG. 5, the processing method of the power diode device includes the following steps:

Step S100, providing at least one power diode device semi-finished product 500 after dry etching. As described above, the dry etching apparatus 300 generates dry etching contaminants such as fine particles (particulate contamination) when etching the lateral exposed surface of the PN junction of the power diode wafer, and the sources of the pollution are as follows: dust in the air Dust and dry etching residues (such as carbon, metals, oxides, etc.) caused by the operation of the operator and the machine. These contaminants often have a significant impact on the component and may even result in a decrease in yield.

Step S102, placing at least one of the power diode device semi-finished products 500 after dry etching in a high volatility solvent, and performing a double-frequency ultrasonic oscillating cleaning step to remove at least one after dry etching. The dry etching contaminant remaining on the power diode device semi-finished product 500. Step S102 can be performed by the dual-frequency ultrasonic cleaning device 100. Specifically, the power diode device semi-finished product 500 can be loaded on a carrier (not shown), and then by a transport device (eg, a robotic arm, not shown). It is transported into the solvent storage tank 102 and immersed in a highly volatile solvent, and then oscillated and cleaned by the high frequency and low frequency ultrasonic waves applied by the dual frequency ultrasonic oscillator 104.

Step S104, performing a second cleaning step on the power diode device semi-finished product 500 after at least one double-frequency ultrasonic vibration cleaning. Step S102 can be performed by the flushing device 200. Specifically, the power diode device semi-finished product 500 can be transported together with the carrier into the flushing tank 202, and then the high volatile solvent continuously sprayed by the spraying mechanism 204 will be applied back to the surface. The contaminants are washed away. It should be noted that the present invention does not limit the manner of the second cleaning, and any cleaning method that can prevent secondary pollution can be applied to this step.

In addition to the above main steps, the processing method of the present invention may also selectively perform step S106, and at least one of the power diode devices after the second cleaning is half-formed. The product is subjected to a drying step. Specifically, the power diode device semi-finished product 500 can be transported together with the carrier into the drying device 400, and the highly volatile solvent remaining on the surface of the power diode device semi-finished product 500 is completely volatilized at an appropriate temperature.

In summary, the present invention utilizes a dual-frequency ultrasonic oscillator to apply a high-frequency ultrasonic wave and a low-frequency ultrasonic wave to a high-volatility solvent, thereby transmitting high-frequency and low-frequency ultrasonic waves in a solvent. The cavitation effect effectively removes various contaminants (especially granular contaminants of different particle sizes) from the power semiconductor device semi-finished product.

Furthermore, the present invention can further utilize the rinsing device to spray a high volatility solvent on the semi-finished product of the power diode device, and can completely remove the contamination due to immersion, so that the dry etched power diode has a good structure. Sex and better electrical properties.

Most importantly, the present invention removes most of the particulate contamination from the surface of the power diode by using the oscillating cleaning step of the dual-frequency ultrasonic wave, and then cooperates with the spray rinsing step to remove the particles that may be immersed by the immersion. The specific realization of the technical means of completely removing pollution to prevent secondary pollution can prevent the occurrence of secondary pollution.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, the equivalents of the present invention and the equivalents of the drawings are all included in the present invention. Within the scope of protection, it is given to Chen Ming.

Step S100 to step S106

Claims (6)

A method for processing a power diode device, comprising the steps of: providing at least one power diode device semi-finished product after dry etching; placing at least one of the power diode device semi-finished products after dry etching at a high volatility And performing a double-frequency ultrasonic oscillating cleaning step to remove the dry etching contaminants remaining on the at least one of the power diode device after the dry etching; and the dual-frequency ultrasonic wave At least one of the power diode device semi-finished products after the shock cleaning is subjected to a second cleaning step. The processing method of the power diode device of claim 1, wherein the time of the oscillating cleaning step of the dual-frequency ultrasonic is between about 40 and 120 seconds, and the time of the second cleaning step is between Between 40 and 120 seconds. The processing method of the power diode device of claim 1, wherein the oscillating cleaning step of the dual-frequency ultrasonic wave comprises simultaneously or alternately applying a high frequency ultrasonic wave and a low frequency ultrasonic wave to the high volatility solvent. The frequency range of the high frequency ultrasonic waves is between about 80 and 150 KHz, and the frequency of the low frequency ultrasonic waves is less than 50 KHz. The method of processing a power diode device according to claim 1, wherein the second cleaning step comprises spraying at least one of the powers after the shock cleaning by the dual-frequency ultrasonic wave with another high-volatility solvent. The semi-finished device of the polar body device is configured to remove the dry-etched contaminant of the surface of at least one of the semi-finished products of the power diode device after the shock cleaning by the dual-frequency ultrasonic wave. The method for processing a power diode device according to claim 4, wherein the high volatility solvent is methanol, ethanol, isopropanol or acetone, and the other high volatility solvent is methanol, ethanol or isopropanol. Or acetone. The method for processing a power diode device according to claim 1, further comprising performing a drying step of the at least one second cleaned power diode device.