CN108568427A - A kind of ultrasonic cleaning equipment of silicon chip - Google Patents

Abstract

The invention discloses a kind of ultrasonic cleaning equipments of silicon chip, belong to wafer cleaning technical.The device includes supersonic wave cleaning machine, locating rack, quartzy pot, rack, water inlet pipe, drainpipe, the locating rack is positioned in supersonic wave cleaning machine, the quartz pot is positioned in locating rack, the rack is positioned in quartzy pot, the water inlet pipe is set to above quartzy pot, and the ultrasonic cleaning motor spindle is provided with drainpipe.Ultrasonic cleaning equipment provided by the invention can clear up the impurity being suspended in after silicon chip surface disengaging in deionized water in time, avoid causing secondary pollution to the silicon chip cleaned, and cleaning performance is good, easy to operate, and personnel are not had to during cleaning and are guarded, time saving and energy saving.

Description

An ultrasonic cleaning device for silicon wafers

technical field

The invention relates to an ultrasonic cleaning device for silicon wafers, belonging to the technical field of silicon wafer cleaning.

Background technique

During the ultrasonic cleaning process of the silicon wafer, the atoms on the surface layer of the wafer are destroyed due to the chemical bonds in the vertical slice direction to form dangling bonds. With the increase of the number of dangling bonds, it is very easy to adsorb various impurities, such as particles, organic impurities, inorganic impurities, metal Ions, silica fume dust, etc. However, potential contamination at every step in silicon wafer production can lead to defects and failure of semiconductor devices. At present, ultrasonic cleaners are generally used to clean silicon wafers. Ultrasonic cleaners are usually equipped with a cleaning tank with a deionized water inlet and outlet on the cleaning tank. A certain amount of deionized water is kept in the cleaning tank, and the deionized water It is always in a flowing state; in addition, when cleaning silicon wafers, the silicon wafers are usually placed in a soft flower basket or on a quartz rod frame.

The above-mentioned ultrasonic cleaning method has the following defects: first, during ultrasonic cleaning, various impurities on the surface of the silicon wafer are gradually separated and suspended in deionized water, and it is difficult to discharge a large amount of impurities to the cleaning tank in time only through the water outlet, which causes After the cleaning work is completed, when the silicon wafer is taken out from the cleaning tank, some impurities suspended in the deionized water are re-adsorbed on the surface of the silicon wafer, causing secondary pollution to the silicon wafer and bringing great difficulties to the subsequent cleaning of the silicon wafer. It even affects the overall quality of the chip; second, the soft flower basket for placing the silicon wafer is made of polytetrafluoroethylene material, and the soft flower basket will absorb and block the transmission of ultrasonic waves during cleaning. In another case, the silicon wafer placed flat on the quartz rod Since there is no limit device to fix it, it keeps shaking during cleaning, which affects the cleaning effect.

Contents of the invention

In order to solve the above technical problems, the present invention provides an ultrasonic cleaning device for silicon wafers.

The present invention is achieved through the following technical solutions: an ultrasonic cleaning device for silicon wafers, comprising an ultrasonic cleaning machine, a positioning frame, a quartz pot, a placing frame, a water inlet pipe, and a drain pipe, the positioning frame is placed in the ultrasonic cleaning machine, and the The quartz pot is placed in a positioning frame, the placement frame is placed in the quartz pot, the water inlet pipe is arranged above the quartz pot, and a drain pipe is arranged at the bottom of the ultrasonic cleaning machine.

The positioning frame is provided with supporting feet.

The quartz jug is provided with a handle.

The spout of the quartz pot is higher than the spout line.

The spout line of the quartz pot is higher than the drain pipe.

The placing frame is provided with a card slot.

The placing frame is provided with supporting feet.

The material for making the shelf is quartz rods.

The water inlet pipe is provided with a valve.

The valve is a ball valve.

The beneficial effects of the present invention are as follows: first, the deionized water in the silicon wafer and the ultrasonic cleaning machine is isolated by adopting a quartz pot, and the deionized water in the quartz pot is always in an overflow state during cleaning, and the overflowing deionized water can promptly remove the The impurities separated from the surface of the silicon wafer are taken out of the quartz pot to avoid secondary pollution of the silicon wafer in the quartz pot by impurities; second, the quartz pot and the rack are made of quartz, and the ultrasonic wave has a good penetration on the quartz Effect, in addition, there is a card slot on the shelf, and the silicon wafer is inserted into it more stably, and the cleaning effect is better; third, the operation is convenient, and there is no need for personnel to guard the silicon wafer during cleaning, saving time and effort.

Description of drawings

Fig. 1 is the full sectional structure schematic diagram of the present invention;

Fig. 2 is the structural representation of positioning frame of the present invention;

Fig. 3 is the structural representation of quartz pot of the present invention;

Fig. 4 is the structural representation of the placement rack of the invention;

In the figure: 1-ultrasonic cleaning machine, 2-positioning frame, 3-quartz pot, 4-placement frame, 5-inlet pipe, 51-valve, 6-drainage pipe.

Detailed ways

The technical solution of the present invention will be further described below in conjunction with the drawings in the embodiments, but the scope of protection is not limited to the description.

As shown in Fig. 1 to Fig. 4, the present invention provides the following technical solutions: a kind of ultrasonic cleaning device for silicon wafers, comprising ultrasonic cleaning machine 1, positioning frame 2, quartz pot 3, placement frame 4, water inlet pipe 5, drain pipe 6, all The positioning frame 2 is placed in the ultrasonic cleaning machine 1, the quartz pot 3 is placed in the positioning frame 2, the placement frame 4 is placed in the quartz pot 3, the water inlet pipe 5 is arranged above the quartz pot 3, and the The bottom of the ultrasonic cleaning machine 1 is provided with a drain pipe 6 .

Further, the positioning frame 2 is provided with supporting feet, which is convenient for taking and placing the positioning frame 2 and better defines the quartz pot 3 .

Further, the quartz pot 3 is provided with a handle, which is convenient for picking and placing the quartz pot 3 .

Further, the spout of the quartz pot 3 is higher than the spout line, so as to ensure that the deionized water in the quartz pot 3 overflows from the spout line, and the impurities in the quartz pot 3 are discharged in a more timely manner.

Further, the spout line of the quartz pot 3 is higher than the drain pipe 6, so that the deionized water in the quartz pot 3 and the deionized water in the ultrasonic cleaner 1 form a ladder, preventing the deionized water in the ultrasonic cleaner 1 from flooding the quartz pot 3.

Further, the placing frame 4 is provided with a card slot to effectively stabilize the silicon wafer 7 placed in the card slot.

Further, the placing frame 4 is provided with supporting feet, which facilitates taking and placing the placing frame 4 and better limits the silicon wafer 7 inserted into the slot of the placing frame 4 .

Further, the material of the placing frame 4 is a quartz rod, and the ultrasonic wave can achieve a better penetrating effect than the soft flower basket.

Further, the water inlet pipe 5 is provided with a valve 51, which is convenient for controlling the opening, closing and flow of deionized water.

Further, the valve 51 is a ball valve.

A kind of ultrasonic cleaning device of silicon wafer according to the present invention, wherein the structure and working principle of ultrasonic cleaning machine 1 are as follows:

The ultrasonic cleaning machine 1 mainly includes a cleaning tank, an ultrasonic vibrator, and an ultrasonic generator. The ultrasonic vibrator is installed at the bottom of the cleaning tank. The ultrasonic generator is connected to the ultrasonic vibrator through a circuit. The cleaning tank is used to load deionized water and the workpiece to be cleaned. The cleaning tank can It is rectangular, circular, oval, etc. The function of the ultrasonic vibrator is to convert the electric power into ultrasonic waves and transmit them out. The function of the ultrasonic generator is to convert the mains power into the corresponding high-frequency alternating current of the ultrasonic vibrator to drive the ultrasonic vibrator to work; open The ultrasonic generator drives the ultrasonic vibrator to generate ultrasonic waves, and transmits ultrasonic waves to the deionized water in the cleaning tank and quartz pot 3. Ultrasonic waves are a kind of dense and dense vibration waves, which can make the medium pressure alternately change, and produce tearing in the deionized water. cracking force, and form vacuum cavitation at the same time, the vacuum cavitation is crushed and burst by the compression force behind, this kind of vibration under the action of sound field, when the sound pressure reaches a certain value of ultrasonic cleaning, the bubble will grow rapidly, and then Sudden closure, when the bubbles are closed, strong shock waves are generated due to the collision between the liquids, and a pressure of thousands of atmospheres is generated around the bubbles, that is, "ultrasonic cavitation". Therefore, the cleaning of the "impurities" on the surface of the silicon wafer 7 mainly comes from the following points: 1. The powerful shock wave generated when the cavitation bubbles burst, the "impurities" on the surface of the silicon wafer 7 are stripped off and scattered; 2. Cavitation The bubbles produced by the phenomenon expand and shrink simultaneously with the raw pressure, and produce a physical force like peeling that repeatedly acts on the "impurities" on the surface of the silicon wafer 7; 3. The ultrasonic vibration of deionized water in ultrasonic cleaning itself cleans the surface of the silicon wafer 7 force.

In the present invention, objects such as the water inlet pipe 5 and the quartz pot 3 are further added to the ultrasonic cleaning machine 1 to form a ladder flow mode as a whole, so that the deionized water can clean up the "impurities" separated from the silicon chip 7 in time out of the quartz pot 3. After the cleaning work is completed, when the silicon wafer 7 is taken out of the deionized water, impurities will cause secondary pollution to the silicon wafer.

A kind of ultrasonic cleaning device of silicon chip according to the present invention, its cleaning method mainly comprises the following steps:

(1) Place the silicon chip: insert the silicon chip 7 into the slot of the placing frame 4, and put the quartz pot 3 into the positioning frame 2 correspondingly;

(2) filling deionized water: open the valve 51 on the water inlet pipe 5, add deionized water to the quartz pot 3 and the ultrasonic cleaner 1, until a small amount of deionized water begins to flow out in the drain pipe 6;

(3) cleaning: turn on the ultrasonic cleaning machine 1, and ultrasonically clean the silicon wafer 7 for 10 to 15 minutes;

(4) Washing, rinsing: close the ultrasonic cleaning machine 1 and the valve 51, take out the quartz pot 3 from the ultrasonic cleaning machine 1, pour off the deionized water in the quartz pot 3, take out the silicon chip 7 from the placement rack 4, and use Rinse and rinse with ionized pure water, and complete the super-cleaning work after drying.

Example 1:

Open a hole on the ultrasonic cleaning machine 1 to install the water inlet pipe 5, and install a ball valve 51 on the water inlet pipe 5, insert the silicon chip 7 into the slot of the placement frame 4, and put the quartz pot 3 with the placement frame 4 into it correspondingly. Go to the positioning frame 2, open the ball valve 51 and inject deionized water into the quartz pot 3 and the ultrasonic cleaner 1 until a small amount of deionized water begins to flow out in the drain pipe 6, and adjust the injection speed of the deionized water in the water inlet pipe 5 to ensure During cleaning, the drain pipe 6 can remove the deionized water overflowing from the quartz pot 3 in time to prevent the deionized water level in the ultrasonic cleaner 1 from gradually rising and submerging the quartz pot 3. Turn on the ultrasonic cleaner 1 to start cleaning. After 15 minutes Take out the quartz pot 3, pour out the deionized water in the quartz pot 3, take out the silicon wafer 7 from the rack 4, wash, rinse and dry the silicon wafer 7 with deionized pure water, and complete the ultrasonic cleaning of the silicon wafer 7.

Claims (10)

1. an ultrasonic cleaning device for silicon wafers, characterized in that: comprise ultrasonic cleaning machine (1), positioning frame (2), quartz pot (3), placement frame (4), water inlet pipe (5), drainpipe ( 6), the positioning frame (2) is placed in the ultrasonic cleaning machine (1), the quartz pot (3) is placed in the positioning frame (2), and the positioning frame (4) is placed in the quartz pot (3) Inside, the water inlet pipe (5) is arranged above the quartz pot (3), and a drain pipe (6) is arranged at the bottom of the ultrasonic cleaning machine (1). 2. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the positioning frame (2) is provided with supporting feet. 3. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the quartz pot (3) is provided with a handle. 4. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the spout of the quartz pot (3) is higher than the spout line. 5. The ultrasonic cleaning device for silicon wafers according to claim 4, characterized in that: the spout line of the quartz pot (3) is higher than the drain pipe (6). 6. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the placing frame (4) is provided with a card slot. 7. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the placing frame (4) is provided with supporting feet. 8. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the material of the placing frame (4) is quartz rods. 9. The ultrasonic cleaning device for silicon wafers according to claim 1, characterized in that: the water inlet pipe (5) is provided with a valve (51). 10. The ultrasonic cleaning device for silicon wafers according to claim 9, characterized in that: the valve (51) is a ball valve.