TW201027604A - Methods and apparatus for cleaning semiconductor wafers - Google Patents

Abstract

A method for cleaning semiconductor substrate using ultra/mega sonic device comprising holding a semiconductor substrate by using a chuck, positioning a ultra/mega sonic device adjacent to the semiconductor substrate, injecting chemical liquid on the semiconductor substrate and gap between the semiconductor substrate and the ultra/mega sonic device, changing gap between the semiconductor substrate and the ultra/mega sonic device for each rotation of the chuck during the cleaning process. The gap can be increased or reduced by 0.5 λ/N for each rotation of the chuck, where λ is wavelength of ultra/mega sonic wave, N is an integer number between 2 and 1000. The gap is varied in the range of 0.5 λn during the cleaning process, where λ is wavelength of ultra/mega sonic wave, and n is an integer number starting from 1.

Description

201027604 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method and apparatus for cleaning semiconductor wafers. To put it bluntly, it is about the relative spacing between the ultrasonic or megasonic device and the surface of the debris during the cleaning process, so that the ultrasonic or megasonic energy density on the surface of the cymbal is effectively The particles on the surface of the bract are removed without damaging the surface element structure. [Prior Art] A semiconductor device is formed on a semiconductor wafer by a series of different processing steps to form a transistor and an interconnect. "A dielectric element that allows the transistor terminal to be connected to the cymbal. Electrically conductive (e.g., metal) trenches, holes, and other similar structures are formed as part of the device. Slots and holes can be used to transfer electrical signals and energy between transistors, internal circuits, and externalities. In the formation of interconnect elements, semiconductor dies may require processes such as masking, etching, and deposition to form the electronic circuitry required for semiconductor devices. In particular, a multi-layer mask and plasma etch process can form a pattern of recessed regions in the dielectric layer of the semiconductor chip for serving as trenches and vias for interconnect lines. In order to remove particles and contamination generated in the grooves and through holes during engraving or photoresist ashing, a wet cleaning step must be performed. In particular, the device fabrication nodes are constantly approaching and less than 65 nm, and the sidewalls of the trenches and vias are the key to maintaining critical dimensions. In order to reduce or eliminate sidewall loss, apply mild, diluted chemical reagents, or sometimes only deionized water. 4 201027604 Important However, diluted chemical reagents or deionized water often do not effectively remove particles in the tank and through-holes. . Therefore, in order to effectively remove particles, mechanical devices such as ultrasonic or megasonic devices are required. Ultrasonic or facsimile wave surfaces provide mechanical force. 'Energy density and energy distribution are the numbers that control and damage the surface of the wafer while effectively removing particles. ❹: U.S. Patent No. 4,326,553 teaches the use of a dead acoustic wave nozzle to clean semiconductor cymbals. The fluid is pressurized and applied to the fluid by a megasonic sensor. The specific shape = like a strip of liquid, in the stone "矣" method I nozzle sprayed on the surface of the bracts to vibrate at a megasonic frequency. In the US patent Ν〇. 6 〇 39,. 59 mentioned a moving a slender pendulum face level Α 耨 振 振 , , , , , , , 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体 流体In the surface of the eve, a short probe tip is placed on the surface. ^, during the slice rotation process, the probe in the Shi Xi film patent NQ. 6, Μ 3, such as Μ 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提 提The surface of the rod is engraved into a spiral groove. The key to the proper amount of uniform washing process for the entire bract surface is the key to clearing. If the megasonic surface, get less dead cockroaches, the county hook is applied to the enamel sheet net, the granules and the polluted pus ▲, the 矽 矽 邰 将 will not break the surface of the dry ultrasonic energy of the sheet 'and get too many pieces of mouth P The device structure on the surface of the knife may be damaged. 5 201027604 In order to solve the problem and remove the particles and contamination of the fragment or the surface of the substrate with low damage to the structure, a good method is needed to control the energy density distribution of the (4) sonic section. The present invention introduces a box of ancient and earthen aristocrats. In the cleaning process, the mega-acoustic sound is placed toward the front side of the rotating cymbal, so that the megasonic device and the cymbal hard cymbal are added. The spacing between the rotations of the cymbals is the megasonic semi-turbidity I ^ ν. Within the range, the total increase in the length and the distance is the initial integer. λ The wavelength of the dead sound wave, Ν It is introduced from the present invention by a method in which the device is turned toward the rotating cymbal ^ 将 将 / / , , , , , , , , , , , , , , , 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆The spacing between the pieces. Shi Xi The reduction value of the volume of the volume is 簦, ± i 7 pieces of the mother pattern turns one circle, the value is within the range of 0.5 Ν, ★, 卩, and the total width of the spacing is reduced by the integer starting at 1. Here is The wavelength of the megasonic wave, Ν is a method of its J force introduced from the present invention. In the process of cleaning the peaks, the wind & 1 device toward the rotation & lip wash, the megasonic wave is back, and as the 々 continues to increase The continuous rotation of the large megasonic device and the eve film, the gap between the hair pieces. The increment of the spacing is a lap of the mega-sound piece, "part of the wavelength of the skin, in the 〇·5 and Ν Within the range, ^ ^ and the total increase in the spacing begins with an integer. ^ λ 疋 * * The wavelength of the sound wave, Ν is from j 6 201027604 Another method introduced by the present invention 疋 During the cleaning process, the device is rotating toward the 矽The film will continue to reduce the megasonic wave and the heartbeat

Ba ^ The spacing between the sheets. The reduction value of the pitch of each rotation of the cymbal is mega-according, the ancient circle, and the value is 0.5 λ 之 in the range of n λ # ^ ❿ total reduction. The table λ is an integer starting from the wavelength 1 of the megasonic wave. From [Implementation] Figure 1A to ® 1B show that the common device cleaning device for the megasonic instrument includes a discussion, and the rotating cymbal clamp 1〇14 is controlled by the rotary transmission device 1016 to transmit the cleaning liquefaction or The mouth of the deionized water 1Q32 is m2, and the wave device 丨(10). The wave device is composed of the migrating sensor and its companion. After the sensor is de-energized, it acts like a vibration, and the resonance: 2 8 will transmit the still-frequency sound energy into the liquid. The vibration of the washing liquid generated by the megasonic energy is loosened compared to the W 1Q1Q surface, and the flowing liquid 1032 supplied from the nozzle m2 removes it from the surface of the matte. r As shown in Fig. 1c, in order to obtain the minimum amount of reflected energy, the reflected wave, Γ1 (ejected from the upper surface of the water film)# phase must be opposite to the phase of the reflected wave R2 (ejected from the lower surface of the leeches). Equivalent to:, Ω " lj 2,3 (1) where d is the thickness of the water film or the distance between the megasonic device 1〇〇3 and the Shixi piece 1010, η κ solid integer, and λ is the dead sound wave The wavelength of 7 201027604 in water. For example, 'when the frequency of the megasonic wave is 937. 5Κ Hz, λ = i 6 mm, d = 〇· 8 mm,! · 6 mm, 2 4 dragons, etc.

Fig. 1D shows the relationship between the pitch d and the energy density of 1 megasonic wave measured by the sensor 1 〇〇 2 shown in Fig. U. In the range where the pitch is increased to 〇. 4 coffee, a plurality of energy density values from a valley value of 20 w/cm 2 to a peak value of 80 w/cm 2 can be obtained, and the pitch can be increased to 〇8ηΐ]η (〇5λ). When you get a complete cycle. Accurate and stable control of the spacing is the key to the uniform distribution of dead sound energy distribution. , β However, it is actually difficult to accurately maintain a uniform spacing, especially when the cymbal is in the rotating mode. As shown in Fig. 2, if the cymbal clip "Η is 100% perpendicular to the surface of the dead acoustic wave device 2003, the distance between the megasound f and the cymbal 2010 surface will be from the edge of the cymbal to the center of the cymbal. According to the data shown in item 1D, This will cause uneven distribution of the megasonic energy distribution from the edge of the stone slab. It can be seen as shown in Figures 3A and 3B. Another reason for the change in spacing is: Time: The rotation axis of the dream clip is not perpendicular to the stone. The eve gives the surface. The rotation is after two: move, Figure 3B is not rotated from the state shown in Figure 3A by 18° to the distance at the edge of Figure 3BV's from the maximum device shown in Figure 3A: minimum This will cause the megasonic energy density distribution of the debris surface to be uneven when the film passes through the dead wave. The uneven energy distribution will cause the enamel sheet to clean the uneven sentence. Structural damage and

The amount distribution overcomes the variation of the spacing during the rotation of the cymbal clip, and the present invention discloses a method as shown in FIG. The spacing between the megasonic device 4003 and the cymbal 4010 is increased or decreased by the control screw 4〇〇5 @达4006' during the cleaning process at 8 201027604. The control unit weight 8 is used to control the speed of the motor 4_ based on the speed of the motor "Μ. The fragment 4010 or the slick 4014 per revolution control unit 4088 commands the motor 4006 to control the stroboscopic device 4003 to move up or down by a distance of :

Δ z = 0.5 λ /N Φ ° The wavelength of the ultrasonic or megasonic wave, ν is an integer from 2 to 1 0 0 0. The details of a further step-by-step are shown in Fig. 5. When the cymbal or cymbal clip has a large pitch per revolution, the energy density of the dead acoustic wave changes from Ρ1 to Ρ2 at the same position of the Shixi tablet. When the pitch is increased to half the wavelength of the megasonic wave, the energy density is one cycle from Ρ1 to Ρ1丨. The starting point of the period depends on the spacing between the megasonic device and the specific position of the singular film, but when the spacing increases to half the wavelength of the megasonic wave, I,

Every. P will give a full cycle of energy density. In other words, when the brother Tianzhao sound wave device moves up the half-wavelength of the megasonic wave (the frequency is 937 5 kHz砵邕η, β_3 KHz is 〇_8mm), even because of Figure 2, Figure 3A and Figure 3B In the middle of the connection of 5 AAfflmiifr solids, the cause of the 导致 导致 导致 兆 兆 : : : : : : : : : : : : : : : : : 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆 兆Each point yields the same amount of megasonic energy density' including the same φ + Λ At 均 average tb density, the same maximum energy density and the same minimum energy concentration. The process is as follows: In the process 1 (megasonic frequency: f = 937 5 kHz sub-wavelength λ =1 > 6 mm): 9 201027604 Step 1: Spin 1 500 rpm at speed ω. The range of ω is from l〇rpm to step 2. The dead sound wave device is set, and the range of d is (4) the distance between the pieces of the film is d. The dry country is from 5 to 15 mm. Step 3. Turn on the nozzle jet to activate the acoustic wave device. Ionized water or chemical reagents' then open ❹ Step 4: Each rotation of the hair clips moves the megasonic device up to .5λ/Ν (mm), where N is the sorrow and the squat is moving up and the length N is from 2 An integer of up to 1 000. Step 5: Continue the operation of step *, w Λ λα ' until the megaphone is moved up by the distance of .5ηλ (with), where η is the substitution from ". Step 6: Each rotation of the Shixi film clip moves the dead acoustic wave device down 〇·5λ/Ν (off), where Ν is an integer from 2 to 1〇〇〇. Step 7: Continue the operation of step 6 until the dead acoustic wave device moves down the pitch of 5.5ηλ (lai), where η is an integer starting from i. Step 8: Repeat steps 4 through 7 until the cleaning of the Shi Xi tablets is completed. Step 9 1 Stop the spray device and stop spraying the deionized water or chemical reagent to dry the bracts. Process 2 (dead sound wave frequency: f = 937·5 kHz, wavelength in deionized water = 1.6 mm): Step 1. Rotate the cymbal at speed ω, ranging from i 1500 to 1500 rpm Step 2 : Move the megasonic device to a position where the distance between the cymbals is d, and d ranges from 0.5 to 15 mm. Step 3: Open the nozzle to spray deionized water or chemical reagent, then turn on 10 201027604. Start the oscillating wave device. Step 4: Move the megasonic device up every turn of the cymbal clip. 5 again / Ν (job), this襄Ν is an integer from 2 to 1000. Step 5: Continue the operation of step 4 until the dead acoustic wave device moves up ((4)), where η is an integer starting from j. Step 6 • Watch the megasonic wave and stop spraying the deionized water or chemical reagent to dry the bracts.

The frequency of the sensor can be set within the range of ultrasonic and dead sound waves, the magnitude of which depends on the size of the particles being cleaned. The smaller the particle size, the smaller the frequency used. The range of ultrasound is between 2GkHz @州他, and the range of megasonic waves is between 200 and 1“MHz. In order to remove particles of different sizes on the same substrate or the surface of the cymbal, it is necessary to alternate mechanical waves continuously or simultaneously. Frequency. If a double wave frequency is used, the high frequency fl should be an integer multiple of the low frequency f2, and the movement of the sensor should be 0.5" 'the increase or decrease of the pitch of each rotation of the stone Value: Yes. .5 λ"Ν, where λ2 is the wavelength corresponding to the low frequency wave of frequency f2 and the wavelength corresponding to the high frequency wave of frequency f, N is an integer from 2 to i, and η is an integer starting from 1. The following is an example of the use of chemical reagents to remove particles and contamination: Organic removal: H2S〇4:H2〇2 = 4: j Particle reduction: NH4〇H:H2〇2:H2〇= 1:1:5 Metal Pollution removal: HCl: H2 〇 2: H2 〇 = 1:1: 6 Oxide removal: HF: H2 〇 = 1:100 201027604 Figure 6 shows the application of a megasonic instrument to a debris cleaning device in accordance with the present invention - An example. This device is similar to the device shown in Figure 4, except that the cymbal clip is moved vertically by the control of the screw 6005 and the motor 6 〇 06. The control unit 6088 controls the flap A 6〇14 to move up and down by the screw 6〇〇5 and the motor 6〇〇6 to change the spacing between the megasonic package (10) and the Shixi piece 6010.

Figure 7 is a diagram showing another example of applying a megasonic instrument to a cymbal cleaning device in accordance with the present invention. This device is similar to the device shown in Fig. 4, except that the megasonic device 7003 is placed on the back of the cymbal 7〇1, vertically under the control of the screw 7005 and the material 70 〇6. Control a few 88 by screw 7〇〇5 and motor? 〇〇6 to control the dead sound wave = set 7 〇〇丨 move up and down, and then change the spacing between the megasonic device 7 〇〇 3 and the back of the cymbal 7 〇 1 。. Megasonic waves pass through the water film 7〇34 and the bracts 7. i 〇 is transferred to the front of the 7010 and the water film 7〇32. The nozzle 70 Π provides deionized water or a chemical remnant to maintain the water film between the dead acoustic wave device S 7003 and the back surface of the stone plate. The advantage of this device is that the pair of blades 7 which may be caused by dead sound waves can be reduced or eliminated. 〇1〇 Damage to the front device structure. Figure 8 shows another example of the operation of a dead acoustic wave instrument in accordance with the present invention. This device is similar to the device shown in Figure 4: 801, in the Miao film 8 ° 1 ° face down 'and a row of mouth 8 ° 18 toward the stone eve (four) front 1 sound wave through the water Qi and Shi Xi tablets Xie Zhen It is passed to the front of the 8th 1st of Shi Xi tablets. Figure 9 is a diagram showing another example of applying a web cleaning apparatus to a megasonic apparatus in accordance with the present invention. This device is similar to the device shown in Fig. 4, and the same as that of 201027604, the angle between the surface of the piezoelectric sensor 9004 and the cymbal 9〇1〇 is an angle α. The resonator 9008 is connected to the piezoelectric sensor 9A4, and the megasonic wave is transmitted through the resonator 9008 and the deionized water film or chemical reagent film to the Shixi sheet. Processes 1, 2 and 3 can be applied here. Fig. 10A to Fig. 10G show the top view of the megasonic apparatus according to the present invention. The megasonic device shown in Fig. 4 is placed in place of a different shape of the megasonic device 100 03, i.e., the angle shown in Fig. 1 is a shape or a pie shape, Fig. 10

The rectangular shape shown in Fig. 10C is eight pseudo-, θ, edge, angular, elliptical as shown in Fig. 10D,

The semicircular shape shown in Fig. 10A, the quarter circle which is not shown in Fig. 1F, and the circle shown in Fig. 10G. Modifications and Changes Although the present patent has been described with respect to specific embodiments, examples and should be described, the present invention does not exclude those obvious readings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A 1D depicts a typical hair piece cleaning device; Fig. 2 depicts a typical cymbal cleaning process; and Figs. 3A-3B depict another stencil cleaning process. 4 describes another typical mc ^ cymbal rinsing device; Figure 5 depicts a cymbal cleaning method Figure 6 depicts another typical 矽 Figure 7 depicts another typical = device Figure 8 depicts another Typical sand: washing device ^ q ^ ^ , fry cleaning device Figure 9 depicts another typical % sheet cleaning device 13 201027604 Figure 1 0A-1 0G describes various shapes of ultrasonic or megasonic sensors

shape. [Main component symbol description] 1002: Sensor 10 04 : Sensor 1010 : Sepal 1014 : Septum clamp 1032 : Deionized water (flowing liquid) 2010 : Septum 3 0 1 0 : Sepal 4〇〇5 : screw 4010 : cymbal 4016 : motor 6003 : megasonic device 6006 : motor 6014 : cymbal holder 7003 : megasonic device 7006 : motor 7011 : nozzle 7034 · water film 8010 : cymbal 8032 : water film 9008 : resonator 10003: megasonic device 1003: megasonic device 1008: resonator 1 0 1 2 : nozzle 1016: rotary transmission 2003: megasonic device 2014: cymbal clamp 4003: megasonic device 4006: motor 4014: cymbal clamp 4088: Control unit 6005: screw 6010: cymbal 6088: control unit 7005: screw 7010: cymbal 7032: water film 7088 · control unit 8018: nozzle 9004: sensor 9010: cymbal 14

Claims (1)

201027604 VII. Application for Patent Park: 1. A method of using ultrasonic or megasonic wave loading, comprising: arranging and holding a semiconductor substrate by using a cymbal clip to clamp the semiconductor substrate; placing a set of ultrasonic or megasonic devices In the vicinity of the semiconductor substrate, at least one nozzle is used to inject the chemical liquid into the gap between the 矽❹* body substrate and the ultrasonic or megasonic device. During the cleaning process, each time the cymbal clip rotates, the gap between the substrate and the ultrasonic or megasonic device is changed + the conductor therein, by which the direction is moved, by changing the movement, for example, applying for a patent The method described in the scope of the invention changes the size of the gap by an ultrasonic or megasonic device perpendicular to the semiconductor substrate. 3. The method of claim 2, wherein the cymbal is clamped to a size perpendicular to the gap of the ultrasonic or megasonic device. 4. The method of claim 2, wherein the "wave" acoustic wave device is placed in a position facing and facing the front side of the semiconductor substrate. 5. The method of claim 1, wherein the wave or megasonic wave The device is placed in a position facing and close to the semiconductor, and the position of the super-sinner is in the back of the substrate. 15 201027604 6. The method of claim 5, wherein the chemical liquid is placed in the semiconductor The first nozzle of the cymbal is attached to the front surface of the semiconductor substrate, and at the same time, the second nozzle, which is placed near the back surface of the semiconductor cymbal, is sprayed onto the back surface of the semiconductor substrate. 7. For the method described in the scope of the patent application, item i + ^, wherein the gap increases by 〇.5λ Λ /Ν ' 每 是 is the wavelength of the ultrasonic or 瘳 声 sound wave 每 every time the cymbal clip rotates one turn Ν Is an integer from 2 to 1 。 8. The method of claim 1, wherein the Shi Xi tablet = rotation - circle 'gap reduction. 5 Λ / Ν, this 襄 λ is ultrasonic Or the wavelength of the dead sound wave, Ν is - The method of claim 2, wherein the gap size varies within the range of 〇5 and n 铭阁Λ物& 牧υ·ΰλη during the cleaning process, here; I is the wavelength of the super θ sound wave or the dead sound wave, and η is an integer from W. The method according to the method of item i of the patent application, the acoustic frequency of the instrument is the cheek rate. The method of the above item, wherein the frequency comprises a high frequency fl and a ^ _ „1 ··· ^ 1 solid low frequency f2, and fl=Mf2, where 寞M is an integer starting from 2. 16 201027604 • 12. The method of claim 11, wherein the fragmentary clip is reduced by 0.5 λ per rotation-' gap, where λ is the wavelength of the high frequency wave of frequency 'fl' from 2 An integer of up to 1 000. 13. The method of claim 11, wherein the gap size varies within a range of 0·5 λ π during the cleaning process, where 2 is the wavelength of the low-frequency wave having a frequency of f2 η is from 1 The starting integer. #14, 斥|J is a device for cleaning a semiconductor substrate by using a super-wave or dead acoustic wave device, comprising: a chip missing from a semiconductor substrate; a set of ultrasonic or megasonic devices placed near the semiconductor substrate; There is a nozzle for injecting a chemical liquid into the gap between the cymbal substrate and the semiconductor substrate and the ultrasonic or megasonic device. During the cleaning process, one rotation of the cymbal holder rotates, and a control unit changes the semiconductor lining. The spacing between the bottom and the ultrasonic or megasonic device. 15. The apparatus of claim 14, wherein the size of the gap is changed by moving the ultrasonic or line wave device in a direction straight from the bottom of the I conductor. The device of claim 14, wherein the size of the gap is changed by moving the cymbal clip in a direction perpendicular to the ultrasonic or megasonic device. 17. The device of claim 14, wherein the super, sonic or megasonic device is placed in a position facing and facing the front side of the semiconductor substrate. 18. The device of claim 14, wherein the ultrasonic or megasonic device is placed in a position facing the back of the semiconductor substrate. 19. The device of claim 18, wherein the first nozzle of the chemical liquid placed near the front side of the semiconductor stone is sprayed onto the front surface of the semiconductor substrate, and the chemical liquid is placed on the back of the semiconductor wafer. A nearby second nozzle is ejected onto the back side of the semiconductor substrate. 20. The device of claim 14, wherein the gap increases by 〇·5 λ /N for each rotation of the cymbal clip, where λ is the wavelength of the ultrasonic 兆 or megasonic wave, and Ν is a from 2 An integer of up to 1 000. 21. The device of claim 14, wherein the crepe clip is rotated by a circle and the gap is reduced by 0.5 λ / Ν, where λ is the wavelength of the ultrasonic or dead sound wave ' Ν is a from 2 An integer to 1000. 22. The device of claim 14, wherein the control unit causes the gap size to vary within a range of 〇. 5 λ η during the cleaning process. Here λ is the wavelength of the ultrasonic or megasonic wave, ^ is from 1 starts with the 201027604 integer. • A device as claimed in claim 14, wherein the ultrasonic or megasonic instrument produces dual wavelengths. 24. The device of claim 23, wherein the dual frequency comprises a high frequency fl and a low frequency f2, and fi = Mf2, where Μ is an integer starting from 2. ❹ 25. The device according to claim 24, wherein each time the cymbal clip is rotated, the gap is increased by 5.5λι/Ν' where ^ is the wavelength of the high frequency wave whose frequency is ,, and N is a value from 2 An integer of 1〇〇〇. 26. The device of claim 24, wherein the gap is reduced by 5 λ l/N for each rotation of the cymbal clip, where λ ι is the wavelength of the high frequency wave of the frequency • fl, An integer from 2 to 1〇〇〇. 27. The device of claim 24, wherein the control unit in the cleaning process causes the gap size to vary within a range of 〇·5 λ ζη, where λ 2 is the wavelength of the low frequency wave of the frequency, ^ is An integer starting at 1. 19