JP2008218664A - Dicing method of semiconductor wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dicing method which will not cause corrosion or hole generation in the part of bonding pad of an element on a semiconductor wafer due to cutting liquid or cooling water used in a dicing device. <P>SOLUTION: The dicing method of semiconductor wafer comprises a first dicing process for moving a rotary blade 13 to the cutting starting position of a neighbored dicing line immediately after cutting the semiconductor wafer 12 to its end part in accordance with a dicing line and a second dicing process for completely removing moisture on the semiconductor wafer surface 12 by feeding further the wafer until the whole of the semiconductor wafer 11 crosses the air injection nozzle 15 after cutting the semiconductor wafer 11 to its end part in accordance with the dicing line and, thereafter, moving the rotary blade 13 to the cutting starting position of the neighbored dicing line. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor wafer dicing method, and more particularly, to a dicing method for cutting a semiconductor wafer while spraying cleaning water and air onto the surface of the semiconductor wafer after passing through the rotary blade. Is.

  As a dicing apparatus for cutting a semiconductor wafer on which an element is formed into a chip shape and a dicing method using the apparatus, those disclosed in Japanese Patent Application Laid-Open No. 2000-141308 are known as conventional examples. This dicing apparatus is arranged at a front upper portion where a semiconductor wafer is sent, a rotary blade that cuts the semiconductor wafer along a dicing line, and a semiconductor wafer that has been cut out. A cleaning water spray nozzle for spraying and an air spray nozzle for spraying air onto the semiconductor wafer are arranged in parallel to the cleaning water spray nozzle and on the outside thereof.

In addition to these, there is a nozzle to which cutting water and cleaning water are supplied, and the semiconductor wafer is cut while supplying the cutting water and the cleaning water toward the cutting point of the rotating blade. In addition, in order to prevent electrostatic breakdown of the elements formed on the semiconductor wafer, these waters contain carbon dioxide gas (melted) in pure water to increase electric conductivity.

JP 2000-141308 A

  In the conventional dicing apparatus and the dicing method using the same, the bonding pad portion of the element formed on the semiconductor wafer may be corroded due to the battery effect (electric corrosion) and may be perforated. This problem is due to the following reason.

First, the time required for dicing is increased along with the miniaturization of the semiconductor circuit. Usually, a semiconductor wafer is formed with a plurality of chips of semiconductor circuit elements that are separated in a dicing process in vertical and horizontal matrices with dicing lines as a boundary. The number of chips that can be taken from the wafer also tends to increase. Along with this, the dicing speed (relative movement speed of the semiconductor wafer holding table) is also reduced from the viewpoint of strength, and the processing time becomes longer. This is because the individual semiconductor circuit elements on the semiconductor wafer are It is the same as being immersed in water (cutting water and cleaning water) for a long time.

Second, in recent years, Al—Cu (Cu: 0.5%) has been used as a bonding pad material to prevent migration, instead of Al—Si, which has been used conventionally. is there.

And the change of the situation of the above-mentioned two semiconductor circuit elements, combined with the use of carbon dioxide melt water for cutting water and cleaning water, causes a hole in the bonding pad due to corrosion due to the battery effect. It was.

An object of the present invention is to provide a dicing method that does not cause corrosion or hole formation in a bonding pad portion of an element on a semiconductor wafer due to cutting water or cooling water used in a dicing apparatus.

A dicing method for a semiconductor wafer according to the present invention includes a table for holding a semiconductor wafer on which elements are formed, a rotating blade for relatively moving the table and cutting the semiconductor wafer along a dicing line, and cutting A cleaning water spray nozzle that is disposed at an upper front portion where the semiconductor wafer is delivered and sprays cleaning water onto the semiconductor wafer, and is disposed outside the semiconductor water in parallel with the cleaning water spray nozzle. A semiconductor wafer dicing method using a cutting apparatus having an air injection nozzle for injecting air,
A first dicing step of moving a rotating blade to a cutting start position of an adjacent dicing line immediately after cutting to the end of the semiconductor wafer according to the dicing line;
After cutting to the end of the semiconductor wafer according to the dicing line, the semiconductor wafer surface is completely removed by feeding further until the entire semiconductor wafer crosses the air injection nozzle, and then the cutting of the adjacent dicing line is started. And a second dicing step for moving the rotating blade to a position.

In addition, the first dicing step and the second dicing step are each performed a plurality of times until the dicing of one semiconductor wafer is completed, and one of the second dicing steps performed a plurality of times. The part includes a kerf check process.

  In addition, the first dicing step and the second dicing step are each performed a plurality of times until the dicing of one semiconductor wafer is completed, and one of the second dicing steps performed a plurality of times. A setup process is included in the part.

In addition, the first dicing step and the second dicing step are each performed a plurality of times until the dicing of one semiconductor wafer is completed, and the second dicing step is performed for the first dicing step 30 times or less. It is characterized in that it is set at a frequency of one dicing step.

In the second dicing step, air sprayed from the air spray nozzles is sprayed from the plurality of nozzle holes to the entire surface of the semiconductor wafer, and the strength is 0.1 m / second or more in wind speed. The relative moving speed is 10 to 70 mm / sec.

In the dicing method according to the present invention, it is possible to prevent the bonding pad portion of the element formed on the semiconductor wafer from being corroded by the battery effect (electric corrosion) and causing a hole.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view showing a cutting apparatus according to an embodiment of the present invention. FIG. 2 is a view showing the positional relationship between each part when the cutting apparatus shown in FIG. 1 is viewed from the front and the semiconductor wafer placed thereon.

As shown in FIG. 1, the cutting apparatus moves a table 1 holding a semiconductor wafer 2 on which elements are formed, and the table 1 relative to a cutting means, and moves the semiconductor wafer 2 to a dicing line (for example, , And a rotating blade 3 for cutting along vertical and horizontal grid lines drawn on the semiconductor wafer 2 in the figure. The table 1 holding the semiconductor wafer 2 can move relatively in the X direction, Y direction, and height direction shown in the figure when combined with the operation of the main shaft holding the rotary blade 3. Thus, the positional relationship between the semiconductor wafer 2 and the rotary blade 3 is adjusted, and during the cutting operation (for example, when cutting along the dicing line in the X direction), a reciprocating operation in the X direction is performed. The movement of the table 1 in the X direction is not limited to the range in which the rotary blade 3 moves on the semiconductor wafer 2, but on the right side of the drawing, the entire semiconductor wafer 2 can be further fed until it crosses the air injection nozzle 5. It has a configuration like this.

A cleaning water spray nozzle 4 for spraying a water curtain 4a with cleaning water onto the entire semiconductor wafer 2 is disposed on the front upper portion in the X direction to which the cut semiconductor wafer 2 is sent out. In parallel therewith, an air injection nozzle 5 for injecting an air curtain 5a to the entire semiconductor wafer 2 is arranged. Although not shown, a nozzle for injecting cutting water and cooling water is provided on the side of the rotary blade 3.

In addition, a recognition camera 6 is installed behind the cleaning water spray nozzle 4 and the air spray nozzle 5 and at the point where the semiconductor wafer 2 passes under both nozzles 4 and 5, and a kerf check (cut from the dicing line is actually cut). (Position check) is performed periodically.

  Next, a dicing method according to an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a process explanatory view showing a first dicing process, and FIG. 4 is a process explanatory view showing a second first dicing process.

  In FIG. 3, only the semiconductor wafer 12, the rotating blade 13, the cleaning water jet nozzle 14 and the air jet nozzle 15 are shown as the structure, but these all correspond to the parts of the same name shown in FIGS. This part is also present but is omitted from the drawing for easy explanation. The location indicated by symbol A in the figure is the cutting point of the rotary blade 13, the line indicated by symbol B is the locus of movement of the processing point A, and the left and right arrows indicate that the semiconductor wafer 12 is left and right ( The movement in the X direction in FIG. 1 is shown.

The first dicing process is a process of cutting the semiconductor wafer with the rotating blade 13 as shown in FIG. FIG. 3B shows the positional relationship when the semiconductor wafer 12 is cut while moving in the left direction and reaches the left end. Next, along the adjacent dicing line while moving in the direction of the arrow in the figure. Cutting is done. Thereafter, the semiconductor wafer 12 is cut along the adjacent dicing line while moving to the position shown in FIG. 3C, and then moved in the direction of the arrow, and these steps are repeated. Although only one direction dicing line is shown in the figure, since there are dicing lines perpendicular to these, after all of the one direction is completed, the semiconductor wafer 12 is rotated by 90 degrees and fixed in the same manner. repeat.

  FIG. 4 illustrates the second dicing process. FIG. 4A shows the positional relationship when the semiconductor wafer 12 is cut while moving leftward and reaches the left end. Next, along the adjacent dicing line while moving in the direction of the arrow in the figure. Cutting is done. Thereafter, the semiconductor wafer 12 is cut along the adjacent dicing line while moving to the position shown in FIG. In this step, the cut semiconductor wafer 12 is further fed until the entire wafer crosses the cleaning water jet nozzle 14 and the air jet nozzle 15.

Washing water and air (dry air) are constantly jetted from the washing water jet nozzle 14 and the air jet nozzle 15. By being sent to the position shown in FIG. 4B, the semiconductor wafer 12 is cleaned, and the moisture on the surface is completely removed. Then, by periodically setting this state during the first dicing process for cutting the entire semiconductor wafer, the corrosion (electric corrosion) of the bonding pad portion of the element formed on the semiconductor wafer is prevented. Can be prevented. And it is effective to set with the frequency of the 1st dicing process 1 time with respect to the 1st dicing process 30 times or less. It is preferable to shorten the time of continuous immersion in water and increase the frequency of putting a dry state in the second dicing process, but it has a disadvantage that productivity is reduced. Therefore, it is set to be reduced within a range where electric corrosion does not occur.

Moreover, in the dicing process, it is common to provide a kerf check (confirmation of the actual cutting position with the dicing line) process and a setup (confirmation of the worn state of the rotating blade / grindstone) in the middle. By incorporating these into a part of the second dicing process described above, the surface of the semiconductor wafer 12 is always kept dry during the kerf check and setup process, thereby preventing corrosion (electric corrosion) of the bonding pad portion. There is an effect.

In the second dicing process, air sprayed from the air spray nozzle is sprayed over the entire surface of the semiconductor wafer from a plurality of (for example, 2 to 10) nozzle holes, and the strength thereof is a wind speed of 0.1 m / second or more. The relative moving speed of the table is optimally 10 to 70 mm / second. Regarding the strength of the air, it is desirable that the water drains completely when the table passes at the above moving speed. Therefore, it is desirable that the air is strong at a wind speed of 0.1 m / second or more. Since the amount of consumption increases, the actual usage is determined in consideration of the amount of consumption. Further, regarding the moving speed of the table, if the speed is too high, the water is not sufficiently drained, and if it is too slow, the productivity is lowered.

  As described above, in the dicing method of the present invention, it is possible to prevent the bonding pad portion of the element formed on the semiconductor wafer from being corroded due to the battery effect (electric corrosion) and causing a hole.

1 is a perspective view showing a cutting apparatus according to an embodiment of the present invention. It is the figure which showed the positional relationship of each site | part and semiconductor wafer when the cutting apparatus shown by FIG. 1 is seen from the front. It is explanatory drawing of the dicing process which shows the dicing method concerning embodiment of this invention. It is explanatory drawing of the dicing process which shows the dicing method concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Table 2, 12 Semiconductor wafer 3, 13 Rotating blade 4, 14 Washing water injection nozzle 5, 15 Air injection nozzle 6, Recognition camera

Claims (5)

A table that holds a semiconductor wafer on which elements are formed, a rotary blade that relatively moves the table and cuts the semiconductor wafer along a dicing line, and a front upper portion where the cut semiconductor wafer is sent out. A cleaning water spray nozzle that is disposed and sprays cleaning water onto the semiconductor wafer; an air spray nozzle that is disposed outside the cleaning water spray nozzle in parallel with the cleaning water spray nozzle; and A dicing method of a semiconductor wafer by a cutting apparatus having
Immediately after cutting to the end of the semiconductor wafer according to the dicing line, a first dicing step of setting the position of the rotary blade to the cutting start position of the adjacent dicing line;
After cutting to the end of the semiconductor wafer according to the dicing line, the semiconductor wafer surface is completely removed by feeding further until the entire semiconductor wafer crosses the air injection nozzle, and then the position of the rotating blade is adjacent. And a second dicing step of setting the cutting start position of the dicing line. The first dicing step and the second dicing step are each performed a plurality of times until the dicing of one semiconductor wafer is completed, and some of the second dicing steps are performed a plurality of times. 2. The semiconductor wafer dicing method according to claim 1, further comprising a kerf check process.   The first dicing step and the second dicing step are each performed a plurality of times until the dicing of one semiconductor wafer is completed, and some of the second dicing steps are performed a plurality of times. The semiconductor wafer dicing method according to claim 1, further comprising a setup step. By the time the dicing of one semiconductor wafer is completed, the first dicing step and the second dicing step are each performed a plurality of times, and the second dicing step is performed for the first dicing step 30 times or less. 2. The semiconductor wafer dicing method according to claim 1, wherein the dicing method is set once. In the second dicing step, air sprayed from the air spray nozzles is sprayed from the plurality of nozzle holes to the entire surface of the semiconductor wafer, and the strength is 0.1 m / second or more in wind speed. 2. The method of dicing a semiconductor wafer according to claim 1, wherein a relative moving speed is 10 to 70 mm / second.

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