Mega sonic wave cleaning head and have the mega sonic wave purging system of this cleaning head
Technical field
The present invention relates to semiconductor cleaning field, relate to a kind of mega sonic wave cleaning head especially and have the mega sonic wave purging system of this cleaning head.
Background technology
Along with sub-micron and deep-submicron super large-scale integration (ULSI) are being followed " Moore's Law " and are being developed rapidly; The design live width sharply reduces; The volume of semiconductor chip is also more and more littler; How to control the mechanical damage of silicon chip surface material, and under the prerequisite of protection silicon chip surface flatness, reduce the silicon chip defect concentration to greatest extent, control its fraction defective, this has become a major challenge of current semiconductor cleaning technique.Following control electrode of 65 nanometer nodes and capacitance structure are more and more fragile.When the integrated circuit live width becomes littler and littler, the particle that can influence the silicon chip fraction defective is also more and more littler, and the more little more difficult cleaning of particle.On chip, how avoiding the micro-structural damage also is the very difficult problem of tool challenge, and cleaning technique now has a variety of, and mega sonic wave cleans and paid close attention to its special energy mode always.The mechanism that mega sonic wave cleans is by shake frequently effect and combine the chemical reaction of chemical that silicon chip is cleaned of high energy.When cleaning, sending wavelength by transducer is that 1 μ m frequency is the high energy sound wave of 0.8 megahertz, and solution molecule is done accelerated motion under the promotion of this sound wave, and maximum instantaneous velocity can reach 30cm/s.Therefore, formed not the such bubble of ultrasonic waves for cleaning, and can only be, the fine particles of the pollutant that silicon chip surface adheres to has been forced removes and enter into cleaning fluid with fluid wave bump wafer surface at a high speed.Mega sonic wave cleaning polishing sheet can remove on the wafer surface less than the particle of 0.2 μ m, and this method can play the effect that machinery is wiped sheet and two kinds of methods of Chemical cleaning simultaneously.But also have certain defective for the direction of megasonic energy and the control of the uniformity, in cleaning process, the energy perpendicular to Si-gate of generation makes it receive shearing force easy generation flexural deformation even root fracture, and semiconductor is caused damage.
Summary of the invention
The technical problem that (one) will solve
The object of the present invention is to provide a kind of can in cleaning process, the minimizing that semiconductor is caused the mega sonic wave cleaning head of damage and has the mega sonic wave purging system of this cleaning head.
(2) technical scheme
In order to solve the problems of the technologies described above, the present invention provides a kind of mega sonic wave cleaning head, comprising:
Transducer;
Resonator is used to propagate the energy from transducer; This resonator has upper surface and lower surface, and upper surface is coupled to transducer, and resonator inside has the hole array of the vacuum of not penetrating upper surface, lower surface.
Preferably, the geometry in the hole in the array of said hole includes but not limited to: column type, honeycomb fashion.
Preferably, the length in column type hole is 5: 1 to 10: 1 with the equivalent diameter ratio.
Preferably, said transducer comprises:
Upper shell has cable connector, can be connected with power amplifier through cable connector;
Coupling layer comprises piezo-electric crystal and coupling piece, and piezo-electric crystal closely is connected with the upper surface of coupling piece, and coupling layer is through coupling piece and upper shell coupling.
Preferably, said upper shell also has an air admission hole and a steam vent, and inner have one and have a plurality of annular boss that are uniformly distributed with groove upper shell inside is divided into inside loop and outside loop; The cold gas that is fed by air admission hole, interior ring and the groove through upper shell can make coupling layer got rid of by steam vent by even cooling back, thereby realization is to the even cooling of coupling layer.
Preferably, said coupling layer also comprises sealing ring, is located on the coupling piece, is used for the coupling place sealing with coupling piece and upper shell coupling.
Preferably, said coupling piece is processed by single medium or multimedium, and thickness is the integral multiple of 1/4 wavelength.
Preferably, being shaped as but being not limited to of this mega sonic wave cleaning head and said coupling layer: cylindrical, rectangle or ellipse.
Preferably, the area of the hole array in the said resonator is slightly larger than the effective area of piezo-electric crystal.
Preferably, said resonator is as lower house, with the lower surface coupling of coupling piece, and is connected with upper shell through connected nail.
The present invention also provides a kind of mega sonic wave purging system with above-mentioned mega sonic wave cleaning head, and this system also comprises mounting bracket, and said mega sonic wave cleaning head is installed on the mounting bracket regularly or movably.
(3) beneficial effect
Mega sonic wave cleaning head of the present invention adopts the resonator of the hole array of inner impermeable vacuum with cylindrical or other geometry; Play the effect that compensation consumes through the mega sonic wave repeatedly reflection of portion within it; Eliminate the inhomogeneities of vibration wave, realize the even distribution of megasonic energy.When being sprayed with ultra-pure water or chemical liquids on the semiconductor, the uniform fluid wave that produces through mega sonic wave washes out the impurity on the semiconductor, and is pulled away via the mobile of liquid, thereby realizes semi-conductive cleaning, and less to semi-conductive destruction.
Description of drawings
Fig. 1 cleans the sectional structure chart of first embodiment for mega sonic wave of the present invention;
Fig. 2 cleans the assembly drawing of first embodiment for mega sonic wave of the present invention;
Fig. 3 cleans the structure chart of upper casing among the first embodiment for mega sonic wave of the present invention;
Fig. 4 cleans the assembly drawing of coupling layer among the first embodiment for mega sonic wave of the present invention;
Fig. 5 cleans lower house internal structure cutaway view among the first embodiment for mega sonic wave of the present invention;
Fig. 6 is an application sketch map of the present invention.
Label among the figure: 1-upper shell; The 11-groove; The 2-sealing ring; The 3-cable connector; The 4-piezo-electric crystal; The 5-coupling piece; The 6-lower house; The impermeable cylinder hole array of 61-; The 7-connected nail; The 8-inlet suction port; The 81-air admission hole; The 9-exhaust joint; The 91-steam vent; 10-mega sonic wave cleaning head; The 20-silicon chip.
The specific embodiment
Below in conjunction with accompanying drawing and embodiment, specific embodiments of the invention describes in further detail.Following examples are used to explain the present invention, but are not restriction scopes of the present invention.
Mega sonic wave cleaning head of the present invention comprises: transducer resonator, resonator are used to propagate the energy from transducer; This resonator has upper surface and lower surface, and upper surface is coupled to transducer, and resonator inside has the hole array of the vacuum of not penetrating upper surface, lower surface.
Shown in Fig. 1-2, mega sonic wave of the present invention cleans first embodiment and comprises: upper shell 1, coupling layer and lower house 6; In the present embodiment, transducer comprises upper shell 1 and coupling layer, and resonator is lower house 6; Shown in Fig. 1-3; Upper shell 1 (material is PVDF or other corrosion resistance height and intensity nonmetallic materials preferably) has cable connector 3; Can be connected with power amplifier through cable connector 3; And a side has air admission hole 81, steam vent 91 and inner one up and down respectively and has the boss that is uniformly distributed with groove 11, and air admission hole 81, steam vent 91 are respectively through inlet suction port 8 and exhaust joint 9 and external communications; Like Fig. 2 and shown in Figure 4, coupling layer comprises: piezo-electric crystal 4 (lead zirconate titanate of common used material for handling through hyperpolarization), coupling piece 5 and sealing ring 2; Piezo-electric crystal 4 through conducting resinl and coupling piece 5 tight bond together, wherein coupling piece 5 is processed by single medium or multimedium, its thickness is the integral multiple of 1/4 wavelength, and its upper surface can pass through screw line ball stube cable; Sealing ring 2 is located on the coupling piece 5, is used for the coupling place sealing of coupling piece 5 with upper shell 1 coupling; The upper surface and the coupling piece 5 of lower house 6 (but material is the better higher materials of machine additivity of mega sonic wave propagation performances such as quartz or ruby) are coupled, and are connected with upper shell through connected nail 7; Shown in Fig. 1 and 5; Adopt the hole array 61 (also can be honeycomb fashion or other geometry) of the impermeable column type vacuum of the molten quick-fried technology processing of laser in the inside of lower house 6; The area of hole array 61 is slightly larger than the effective area of piezo-electric crystal 4, and the length of cylindrical hole is 5: 1 to 10: 1 with the equivalent diameter ratio, and the mega sonic wave that imports into is fully eliminated through repeatedly reflecting its inhomogeneities; Simultaneously; Lower house is also unsuitable blocked up, and blocked up meeting makes effective energy decay before arriving clean surface of mega sonic wave too much, and cleaning performance reduces.The shape of this mega sonic wave cleaning head and coupling layer can be other geometries such as cylindrical, rectangle or ellipse.
Be connected with power amplifier through cable connector 3 piezo-electric crystal 4 is applied the alternating voltage that a frequency is 1MHz, piezo-electric crystal 4 produces vibration and forms mega sonic wave under the effect of alternating voltage, and mega sonic wave is propagated through coupling piece 5 and lower house 6.When being sprayed with ultra-pure water or chemical liquids on the silicon chip, the uniform fluid wave that produces through mega sonic wave washes out the impurity on the silicon chip, and is pulled away via the mobile of liquid, thereby realizes the cleaning to silicon chip, and destroys less to Si-gate.
In the course of the work; Cold gas by air admission hole 81 feedings; Interior ring through upper shell and groove 11 can make coupling layer got rid of by steam vent 91 by even cooling back, increase the life cycle of coupling layer, and the connection through connected nail; Annular boss can compress coupling layer, makes it tight with being connected of lower house 6.
Mega sonic wave purging system of the present invention, this system also comprises mounting bracket.Upper shell 1 top has three screwed holes to link to each other with the mounting bracket (not shown) of system, and cleaning head 10 is fixing with corresponding mounting bracket spiral shell dress through the screwed hole on it, keeps certain distance (being generally 3mm) with silicon chip 20 surfaces, and is as shown in Figure 6.The relative motion of circumference not only can be carried out between cleaning head and the silicon chip and relative motion radially can be realized; Thereby can drive the mega sonic wave cleaning head along the silicon chip radial motion through support moves; Also can be that support is fixed; Cleaning head is fixedly connected with slide block on the support, drives multiple mode such as cleaning head motion through slide block movement and realizes relative motion.
The above only is a preferred implementation of the present invention; Should be pointed out that for those skilled in the art, under the prerequisite that does not break away from know-why of the present invention; Can also make some improvement and replacement, these improvement and replacement also should be regarded as protection scope of the present invention.