CN212240555U - Substrate thinning equipment with chemical mechanical polishing unit - Google Patents

Abstract

The present disclosure relates to a substrate thinning apparatus having a chemical mechanical polishing unit, which includes: the polishing module comprises a chemical mechanical polishing unit, wherein the chemical mechanical polishing unit comprises a storage piece part, a polishing disc, a polishing pad bonded on the polishing disc, two bearing heads for adsorbing the substrate and driving the substrate to rotate, a trimmer for trimming the polishing pad and a liquid supply part for supplying polishing liquid to the surface of the polishing pad. The method combines grinding, such as ultra-precision grinding and chemical mechanical polishing processes, provides the most economic and effective technical route for processing the substrate, improves the thickness uniformity of the substrate, improves the production efficiency by utilizing two bearing heads, can provide technical support for the stacking process of the ultra-high-density semiconductor, and is an important component for the high-density packaging development of the semiconductor and the like.

Description

Substrate thinning equipment with chemical mechanical polishing unit

Technical Field

The present disclosure relates to the field of semiconductor substrate processing technologies, and in particular, to a substrate thinning apparatus having a chemical mechanical polishing unit.

Background

In a later process stage of manufacturing an Integrated Circuit/semiconductor (IC), in order to reduce a package mounting height, reduce a chip package volume, improve a thermal diffusion efficiency, an electrical property and a mechanical property of a chip, and reduce a processing amount of the chip, a back surface of a substrate needs to be thinned before subsequent packaging, and the thickness of the chip after the back surface is thinned may even reach less than 5% of an initial thickness.

With the rapid development of IC manufacturing technology, substrates tend to have larger diameters in order to increase IC chip yields and reduce unit manufacturing costs. The existing equipment is mostly used for processing small-sized substrates, and the requirement for processing large-diameter substrates cannot be met. As the diameter of the substrate increases, the size of equipment for processing the substrate increases, and the equipment often exceeds the available floor area and is difficult to transport and install.

Meanwhile, with the improvement of IC performance, higher requirements are put on the quality of the substrate, and the surface accuracy, surface integrity, surface roughness, surface damage degree, and the like of the substrate are required to meet very high standards. However, the increase in the size of the substrate causes a series of problems such as easy warpage and deformation of the substrate, difficulty in ensuring the surface accuracy and surface roughness, and low processing efficiency, and the conventional processing technology and equipment cannot meet the requirements. In summary, the thinning process for large-size substrates in the prior art has the problems of poor processing effect and low surface quality.

SUMMERY OF THE UTILITY MODEL

The present disclosure provides a substrate thinning apparatus with a chemical mechanical polishing unit, which is intended to solve at least one of the technical problems existing in the prior art.

The present disclosure provides a substrate thinning apparatus having a chemical mechanical polishing unit, including:

the device comprises an equipment front-end module, a grinding module and a polishing module with a chemical mechanical polishing unit;

the chemical mechanical polishing unit includes that one deposits a piece portion, a polishing dish, one bonds the polishing pad on the polishing dish, two are used for adsorbing the base plate and drive the rotatory carrier head of base plate, a trimmer of repairing the polishing pad and provide the confession liquid portion of polishing pad surface earlier on, two carrier heads are located the polishing dish respectively and are followed two semicircle parts that the length direction of base plate attenuate equipment divided.

In one embodiment, the carrier head includes a plurality of annular, concentric, pressure-adjustable chambers that divide the surface of the substrate into a corresponding plurality of zones, and the pressures applied to the plurality of zones can be individually adjusted by individually controlling the pressures in the plurality of pressure-adjustable chambers.

In one embodiment, the plurality of adjustable pressure chambers is at least seven.

In one embodiment, the carrier head further comprises:

an upper structure connected with a drive shaft of the carrier head;

a substructure connected to the superstructure by a flexible connection, the substructure comprising:

a balancing stand;

a base;

the elastic membrane is used for adsorbing the substrate and exerting downward pressure on the substrate, the elastic membrane is fixed on the lower surface of the base, and the pressure-adjustable chambers are arranged inside the elastic membrane; and

a retaining ring for retaining the substrate below the elastic membrane to prevent the substrate from slipping out, the retaining ring being fixed on the lower surface of the base and arranged outside the elastic membrane around the elastic membrane, the retaining ring protruding from the elastic membrane in the axial direction.

In one embodiment, the loading pressure of the carrier head on each zone of the substrate is adjusted according to the thickness distribution of the substrate after finishing grinding and before chemical mechanical polishing.

In one embodiment, the loading pressure of the carrier head on each zone of the substrate is adjusted according to the thickness distribution of the substrate measured in-line during chemical mechanical polishing of the substrate.

In one embodiment, the apparatus front end module includes a first transport unit for transporting the substrate into or receiving the substrate from the polishing module, the first transport unit including a pick-and-place robot having a base and an extendable or retractable robot arm rotatable on the base, the base being slidably disposed on the first transport track.

In one embodiment, the front end module of the equipment comprises a substrate storage unit, wherein the substrate storage unit is arranged on one side of the front end of the substrate thinning equipment and comprises a plurality of front-opening substrate conveying boxes, the front-opening substrate conveying boxes respectively comprise a front-opening container capable of containing a substrate and a front-opening door structure, and the front-opening door structure is hermetically connected to the outer wall of the substrate thinning equipment.

The substrate can be subjected to ultra-precise flattening processing by the method, the production efficiency can be improved by utilizing the two bearing heads, the technical guarantee can be provided for the ultra-high-density semiconductor stacking process, and the method is an important component for the development of high-density semiconductor packaging.

Drawings

The advantages of the present disclosure will become clearer and more readily appreciated from the detailed description given in conjunction with the following drawings, which are given by way of illustration only, and which do not limit the scope of protection of the present disclosure, wherein:

fig. 1 to 2 show a substrate thinning apparatus in schematic top view and perspective view, respectively;

fig. 3 schematically shows an operation flow of the substrate thinning apparatus shown in fig. 1 to 2;

fig. 4 to 5 show a grinding module of a substrate thinning apparatus in a schematic perspective view and a top view, respectively;

fig. 6 shows in a schematic perspective view a first transfer unit for a substrate thinning apparatus, comprising a dry robot;

fig. 7 shows in a schematic perspective view a third transfer unit for a substrate thinning apparatus, comprising a dry robot and a wet robot;

fig. 8 shows in a schematic perspective view a chemical mechanical polishing unit of the substrate thinning apparatus;

FIG. 9 illustrates, in schematic cross-sectional view, a carrier head of a chemical mechanical polishing unit;

fig. 10 shows a single chamber cleaning device for a substrate thinning apparatus in a schematic perspective view.

Description of reference numerals:

1 front end module of equipment

2 polishing module

3 grinding module

11 substrate memory cell

111 front opening type substrate conveying box

12 first transmission unit

121 get a slice manipulator

122 first transfer track

123 base

21 second transmission unit

22 third transmission unit

23 chemical mechanical polishing unit

24 single-cavity cleaning device

211 fixed buffer memory part

212 Mobile cache part

221 dry mechanical arm

222 wet mechanical arm

231 slice storage part

232 polishing disk

233 polishing pad

234 bearing head

235 trimmer

236 liquid supply part

31 grinding unit

32 fourth transmission unit

33 measuring cell

34 cleaning unit

311 working table

313 rough grinding part

314 rough grinding wheel

315 fine grinding section

316 fine grinding wheel

321 simple manipulator

341 first cleaning part

342 second cleaning part

331 contact type measuring instrument

332 non-contact optical measuring instrument

2341 superstructure

2342 substructure

2343 base

2344 elastic membranes

2345 retaining Ring

Z1 first Chamber

Z2 second Chamber

Z3 third Chamber

Z4 fourth Chamber

Z5 fifth Chamber

2411 bearing part

2412 baffle plate part

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are provided to illustrate the concepts of the present invention; the description is intended to be illustrative and exemplary and should not be taken to limit the scope of the invention. In addition to the embodiments described herein, those skilled in the art will be able to employ other technical solutions which are obvious based on the disclosure of the claims and the specification thereof, and these technical solutions include technical solutions which make any obvious replacement or modification of the embodiments described herein. It is to be understood that, unless otherwise specified, the following descriptions of specific embodiments of the present invention are made for ease of understanding in a natural state where the relevant devices, apparatuses, components, etc. are originally at rest and are not given external control signals and driving forces.

The substrate thinning technology provided by the embodiment of the disclosure is mainly applied to thinning the back surface of the substrate, where the back surface refers to a surface of the substrate where no device is laid, and is generally a substrate, and the substrate material may be silicon, silicon oxide, silicon nitride, silicon carbide, sapphire, or the like.

Fig. 1 and 2 show a substrate thinning apparatus of one embodiment of the present disclosure in schematic top view and perspective view, respectively. The substrate thinning apparatus includes an apparatus front end module 1, a grinding module 3 for performing rough grinding and finish grinding on a substrate, and a polishing module 2 for performing chemical mechanical polishing and substrate transfer on the substrate after the rough grinding and finish grinding are completed.

The equipment front end module 1 is arranged on one side of the front end of the substrate thinning equipment, is a transition module for conveying a substrate from the outside to the inside of an equipment machine table, and is used for realizing the entrance and exit of the substrate so as to realize the dry entrance and dry exit of the substrate. The grinding module 3 is disposed at the end of the substrate thinning apparatus for grinding the substrate, such as performing rough grinding and finish grinding, or performing rough grinding, or performing finish grinding. The polishing module 2 is arranged between the equipment front-end module 1 and the grinding module 3, is used for carrying out chemical mechanical polishing on the substrate by utilizing the bearing head capable of adjusting pressure according to the thickness distribution and subarea of the substrate after the substrate is ground, and also has the function of transmitting the substrate among the three modules. The apparatus front end module 1 includes a substrate storage unit 11 and a first transfer unit 12. The polishing module 2 includes a second transfer unit 21, a third transfer unit 22, a chemical mechanical polishing unit 23, and a single chamber cleaning device 24 (which will be described in further detail below). The grinding module 3 includes a grinding unit 31, a fourth transfer unit 32, a measurement unit 33, and a cleaning unit 34.

Fig. 3 shows, with arrows, an operational flow of the substrate thinning apparatus shown in fig. 1 to 2, including:

the pick-and-place robot 121 of the first transfer unit 12 picks up the substrate from the substrate transport cassette 111 of the substrate storage unit 11;

a fixed buffer 211 for transferring the substrate to the second transfer unit 21 by the pick-and-place robot 121;

the dry robot 221 of the third transfer unit 22 transfers the substrate placed in the fixed buffer 211 to the moving buffer 212, and at this time, the moving buffer 212 approaches the fixed buffer 211;

the moving buffer 212 moves to be close to the grinding module 3 (as shown by a dotted line in fig. 3) with the substrate;

the simple robot of the fourth transfer unit 32 transports the substrate placed in the moving buffer 212 to the table 311 of the grinding unit 31, and fixes the substrate on the suction cup 312 corresponding to the current loading/unloading station;

the table 311 is rotated forward by 120 °, and the substrate is moved to the rough grinding station for rough grinding.

After the rough grinding is completed, the table 311 rotates forward by 120 °, and the substrate is moved to the finish grinding station for finish grinding.

After finish grinding, the table 311 rotates in the reverse direction by 240 °, and the substrate moves to a loading and unloading station;

the ground substrate is cleaned and dried by the cleaning unit 34 at the loading and unloading station, and then taken down by the simple manipulator and placed in the mobile buffer part 212;

the movement buffer unit 212 moves to the other end so that the wet robot 222 of the third transfer unit takes down the substrate and places the substrate in the storage unit 231 of the chemical mechanical polishing unit 23;

the substrate is polished in the chemical mechanical polishing unit 23; and carrying out chemical mechanical polishing on the substrate by utilizing the bearing head capable of adjusting the loading pressure according to the thickness distribution and the subarea of the substrate.

After the chemical mechanical polishing is completed, the substrate is taken out of the storage section 231 by the wet robot 222 of the third transfer unit 22 and then is carried into the single chamber cleaning apparatus 24;

the substrate is cleaned and dried in a single chamber cleaning apparatus 24;

after the substrate is cleaned and dried, the pick-and-place robot 121 of the first transfer unit 12 takes out the cleaned substrate from the single chamber cleaning device 24 and stores the cleaned substrate in the substrate transfer cassette 111.

It will be appreciated that, during the grinding process, depending on the mounting positions of the rough grinding section and the finish grinding section, the table may be moved in a direction of rotation that is completely opposite to the above-described process, in other words, the layout shown in fig. 3 may be adopted such that the table is rotated in the forward direction in the clockwise direction while being rotated in the reverse direction in the counterclockwise direction, or the positions of the rough grinding section and the finish grinding section may be reversed such that the table is rotated in the forward direction in the counterclockwise direction while being rotated in the reverse direction in the clockwise direction. In addition, three substrates can be loaded on the three suckers simultaneously, and each sucker enables the substrate to execute different treatments according to different stations, so that the three working stations work simultaneously, the substrate treatment efficiency is improved, and the equipment utilization rate is improved.

The substrate is sequentially subjected to rough grinding, fine grinding and chemical mechanical polishing treatment, and the method specifically comprises the following steps:

step S1, performing rough grinding on the substrate, for example, using a rough grinding wheel to perform rough grinding on the substrate;

step S2, when the rough grinding is completed, performing a finish grinding on the substrate, for example, performing a finish grinding on the substrate by using a finish grinding wheel; the method comprises the following steps of finishing rough grinding when a first preset condition is reached, wherein the first preset condition is that the thickness of a substrate is measured to be reduced to a first preset value, the first preset value is within 150 micrometers, the thickness of the substrate before grinding is 775 micrometers, so that the reduction amount of hundreds of micrometers is required in the rough grinding process, materials are quickly removed by rough grinding, and the processing efficiency is improved;

and step S3, after finishing the fine grinding, using a carrier head capable of adjusting pressure according to the thickness distribution of the substrate. Wherein the finish grinding is completed when a second preset condition is reached, the second preset condition is that the thickness of the substrate is measured to be reduced to a second preset value, and the second preset value is between 10 and 50 mu m.

The rough grinding process includes: measuring the thickness of the substrate on line during rough grinding; and stopping feeding of the rough grinding tool when the thickness of the substrate reaches a first preset range, so that the rough grinding tool performs light grinding on the substrate for a first preset time.

The fine grinding process comprises the following steps:

1) enabling the fine grinding tool to perform fine grinding according to the initial feeding speed;

2) suspending the finish grinding when the thickness of the substrate reaches an intermediate target value, measuring a finish grinding thickness profile of the substrate, and adjusting a tilt angle of the finish grinding-related member according to the finish grinding thickness profile, wherein the adjusting the tilt angle of the finish grinding-related member includes: at least one of adjusting an inclination angle of a finish-grinding tool, adjusting an inclination angle of a holder for holding a substrate, and adjusting an axial positional relationship between the finish-grinding tool and the holder;

3) enabling the fine grinding tool to perform fine grinding at a second feeding speed; and

4) and stopping feeding of the fine grinding tool when the thickness of the substrate reaches a second preset range, so that the fine grinding tool performs light grinding on the substrate for a second preset time.

When the substrate is ground, the surface to be thinned of the substrate is upwards placed to contact with a grinding tool positioned above the substrate, when the substrate is subjected to chemical mechanical polishing (S3), the surface to be thinned of the substrate is downwards placed to contact with a polishing pad positioned below the substrate, wherein after the substrate is ground and before the substrate is subjected to chemical mechanical polishing, the substrate is subjected to overturning treatment. The surface to be thinned is a back surface of the substrate, and the back surface is an opposite side of a device surface on which the electronic circuit is formed.

The chemical mechanical polishing process comprises:

1) obtaining the thickness distribution of the substrate before polishing; measuring a thickness profile of the finish-ground substrate before chemical mechanical polishing of the substrate, wherein the substrate thickness can be obtained using, for example, a noncontact optical measuring instrument; adjusting the loading pressure of the bearing head to each subarea on the surface of the substrate according to the thickness distribution;

2) pressing the substrate on the polishing pad by using the bearing head to carry out chemical mechanical polishing; during the chemical mechanical polishing of the substrate, measuring the thickness distribution of the substrate on line, and adjusting the loading pressure of the bearing head to each subarea of the substrate according to the thickness distribution of the substrate measured on line; preferably, the thickness mean value corresponding to each partition on the surface of the substrate is calculated based on the thickness distribution; comparing the thickness average value of each partition, and enabling the bearing head to apply corresponding loading pressure on the corresponding partition according to the thickness average value; wherein the loading pressure is positively correlated with the thickness mean of the corresponding partition;

3) it is judged whether or not the polishing stop condition is reached. If the polishing stopping condition is reached, finishing the chemical mechanical polishing; if the stop condition is not met, the process returns to step 34 to continue the chemical mechanical polishing.

In this embodiment, after rough grinding of the substrate, the substrate is subjected to finish grinding, and the finish-ground substrate is subjected to chemical mechanical polishing. The ultra-precision grinding realizes rapid material removal, and has the advantages of large material removal amount, low cost and high efficiency. The chemical mechanical polishing can improve the surface quality of the substrate and realize an ultra-flat and ultra-smooth surface. The method comprehensively considers multiple factors such as processing efficiency, processing cost, surface quality, pollution degree and the like, and the mode of combining the ultra-precision grinding and the chemical mechanical polishing process is the most economic and effective technical route.

In this embodiment, the total thickness deviation of the substrate is improved by the chemical mechanical polishing process. After the chemical mechanical polishing, the total thickness deviation of the substrate is reduced to be within 1 μm, the thickness of the substrate is reduced by 3 to 5 μm in the chemical mechanical polishing process, and the thickness of the substrate is reduced to be 7 to 10 μm after the polishing.

The substrate is placed upwards to be thinned in the coarse grinding process and the fine grinding process so as to contact the grinding wheel positioned above the substrate, and the coarse grinding process and the fine grinding process use the grinding wheel positioned above the substrate to rotate relative to the surface of the substrate so as to remove surface materials, so that the surface to be thinned of the substrate is placed upwards for grinding.

The base plate is in among the chemical mechanical polishing process do treat that the attenuate face is placed downwards with the polishing pad of contact position in base plate below, and chemical mechanical polishing process utilizes the carrier head to press the base plate on the polishing pad motion makes the base plate surface with the polishing pad contact removed gradually, so the face of treating the attenuate of base plate should place downwards and polish.

In this embodiment, since the substrate is subjected to rough grinding, finish grinding and chemical mechanical polishing on the same surface, that is, the surface to be thinned is a silicon substrate surface, the surface to be thinned of the substrate faces upward during grinding, and the surface to be thinned of the substrate faces downward during chemical mechanical polishing, the substrate needs to be turned over after the grinding process is completed, and the substrate can be turned over by using the third transmission unit.

The specific composition structure and function of each module are described below.

Device front-end module 1:

as shown in fig. 1 and 2, the apparatus front end module 1 includes a substrate storage unit 11 and a first transfer unit 12. The substrate storage unit 11 is disposed at a front end side of the substrate thinning apparatus, and the first transfer unit 12 is disposed between the substrate storage unit 11 and the polishing module 2, for effecting transfer of the substrate between the substrate storage unit 11 and the polishing module 2.

The substrate storage unit 11 is composed of a plurality of Front Opening Unified Pod (FOUP) 111, and specifically may be two, three, or the like. The front-opening substrate transport box 111 is a container used for protecting, transporting and storing substrates in a semiconductor process, and its main components are a front-opening container capable of accommodating substrates and a front-opening door structure hermetically connected to an outer wall of a substrate thinning apparatus so as to communicate the front-opening container with the inside of the apparatus.

As shown in fig. 6, the first transfer unit 12 includes a pick-and-place robot 121 and a first transfer rail 122, a base 123 of the pick-and-place robot 121 is disposed on the first transfer rail 122, the base 123 is slidable on the first transfer rail 122 to move between different positions, and a robot arm of the pick-and-place robot 121 is rotatable on the base 123 and is extendable or collapsible. The chip taking and placing manipulator is a drying manipulator and is used for taking and placing dry and clean substrates. The pick-and-place robot may pick up a substrate to be processed from the substrate storage unit 11 through the door structure of the substrate transport box 111 and send the substrate to the polishing module 2, and may also receive the processed substrate from the polishing module 2 and place the substrate in the substrate transport box 111.

Grinding module 3:

as shown in fig. 1 and 2, the grinding module 3 includes a grinding unit 31, a fourth transfer unit 32, a measuring unit 33, and a cleaning unit 34.

Fig. 4 and 5 show the grinding unit 31 in a schematic perspective view and a plan view, respectively. The illustrated grinding unit 31 includes a table 311, a rough grinding section 313, a finish grinding section 315, and a grinding liquid supply section. The table 311 is provided with a suction cup 312 for sucking the substrate, the rough grinding portion 313 is provided with a rough grinding wheel 314 for rough grinding the substrate, and the finish grinding portion 315 is provided with a finish grinding wheel 316 for finish grinding the substrate. The grinding process is to press a grinding wheel against the surface of the substrate and rotate the grinding wheel to grind off a certain thickness.

The workbench 311 can rotate around a vertical central axis thereof, three suckers which can rotate independently are uniformly distributed on the workbench and are respectively a first sucker, a second sucker and a third sucker, the three suckers are porous ceramic suckers with completely identical structures so as to realize vacuum adsorption of a substrate, and the centers of the three suckers and a connecting line of the center of the workbench 311 mutually form an included angle of 120 degrees. The three suction cups correspond to three stations 312, a rough grinding station, a finish grinding station, and a loading and unloading station, wherein two stations opposite to the grinding wheel are used for rough grinding and finish grinding, respectively, and one station is left for loading and unloading and cleaning of the substrate. The three suckers can be driven to switch among the three stations through the rotation of the workbench, so that the suckers can carry the substrate to circularly move according to the sequence of the loading and unloading station, the rough grinding station, the fine grinding station and the loading and unloading station. The present embodiment achieves full-automatic loading and unloading and continuous grinding and cleaning of the substrate by repeated cycles. The rotary worktable type substrate grinding has the advantages of high material removal rate, small substrate surface damage and easy realization of automation.

The rough grinding part 313 comprises a rough grinding wheel 314 in a cup-shaped structure, a rough grinding main shaft seat and a rough grinding feeding mechanism, the rough grinding wheel is connected to the bottom of the rough grinding main shaft to enable the rough grinding main shaft to drive the rough grinding wheel to rotate, so that the rough grinding wheel can rotatably grind the surface of a substrate, the rough grinding main shaft is connected with the rough grinding feeding mechanism through the rough grinding main shaft seat to move up and down, and the rough grinding wheel is controlled by the rough grinding feeding mechanism to carry out axial plunge feeding grinding relative to the substrate. In this embodiment, the rough grinding wheel may be a diamond grinding wheel, the surface of which is rough to realize rapid substrate grinding, reducing the substrate thinning time. During rough grinding, the feeding speed of the rough grinding wheel relative to the substrate is 2-10 μm/s so as to realize high-speed feeding, and the rotating speed of the rough grinding wheel is 2000-4000 rpm. The radius of the rough grinding wheel is matched with the radius of the substrate, and can be 1 to 1.2 times of the radius of the substrate. The thickness of the substrate is reduced by more than 600 μm in the rough grinding process, and after the rough grinding, the thickness of the substrate can be reduced to be within 150 μm.

The finish grinding portion 315 includes a finish grinding wheel 316 in a cup-shaped structure, a finish grinding spindle base and a finish grinding feed mechanism, the finish grinding wheel is connected to the bottom of the finish grinding spindle so that the finish grinding spindle drives the finish grinding wheel to rotate, thereby realizing the rotary grinding of the finish grinding wheel to the surface of the substrate, the finish grinding spindle is connected with the finish grinding feed mechanism through the finish grinding spindle base to move up and down, and the finish grinding wheel is controlled by the finish grinding feed mechanism to perform axial plunge feed grinding relative to the substrate. In this embodiment, the finish grinding wheel may be a diamond grinding wheel having a surface roughness lower than that of the rough grinding wheel, and since severe surface defects and losses may be generated by rapidly removing the surface material of the substrate by the rough grinding, the fine surface of the finish grinding wheel is used for low-speed grinding to reduce the thickness of the damaged layer on the surface of the substrate and improve the surface quality of the substrate. In the finish grinding, the feed speed of the finish grinding wheel relative to the substrate is 0.1-1 μm/s so as to realize low-speed feed to improve the grinding precision, and the rotating speed of the finish grinding wheel is 2000-4000 rpm. The radius of the finish grinding wheel matches the radius of the substrate and may be 1 to 1.2 times the radius of the substrate. The thickness of the substrate is reduced by the finish grinding process to be 50 to 100 μm, and after the finish grinding, the thickness of the substrate may be reduced to be 10 to 50 μm.

The grinding fluid supply part is used for spraying grinding fluid to the surface of the substrate to assist grinding during rough grinding and/or fine grinding, and the grinding fluid can be deionized water.

The fourth transfer unit 32 includes a simple robot 321, the simple robot 321 takes the substrate from the moving buffer 212 and feeds the substrate into the grinding unit 31 for grinding, and after the grinding and cleaning are completed, the simple robot 321 takes the substrate from the grinding unit 31 and places the substrate in the moving buffer 212 for subsequent transfer of the substrate. The simple robot 321 is provided therein with a vacuum line to vacuum-adsorb the substrate.

The measurement unit 33 includes a contact-type measuring instrument 331 and a non-contact-type optical measuring instrument 332, and can realize online monitoring of the substrate thickness. The probe of the contact type measuring instrument is pressed on the surface of the substrate to measure the thickness of the substrate by using the height difference of the upper surface and the lower surface of the substrate. The contact measuring apparatus is provided with two sets, which are respectively arranged in the rough grinding part 313 and the fine grinding part 315. The non-contact optical measuring instrument irradiates the substrate with infrared light and calculates the thickness of the substrate according to different reflected lights of the upper surface and the lower surface of the substrate.

The cleaning unit 34 includes a first cleaning part 341 and a second cleaning part 342. The first cleaning portion 341 is used for cleaning and polishing the suction cup, and has a rotatable first body, the bottom of the first body is provided with a suction cup cleaning brush and a suction cup polishing oilstone, and the bottom of the first body is also provided with a through hole for spraying cleaning fluid to the suction cup through a pipeline inside the first body. The second cleaning part 342 is used for cleaning the substrate, and has a rotatable second body, a brush for cleaning the substrate is provided at the bottom of the second body, and a through hole is further provided at the bottom of the second body to spray cleaning liquid to the substrate through a pipe inside the second body.

And (3) polishing module 2:

as shown in fig. 1 and 2, the polishing module 2 includes a second transfer unit 21, a third transfer unit 22, a chemical mechanical polishing unit 23, and a single chamber cleaning device 24. The chemical mechanical polishing unit 23 and the second transfer unit 21 are arranged in parallel along the length direction of the apparatus. The single chamber cleaning device 24 is located between the first transfer unit 12 and the chemical mechanical polishing unit 23. The third transfer unit 22 is adjacent to the first transfer unit 12, the second transfer unit 21, the chemical mechanical polishing unit 23, and the single chamber cleaning device 24, and serves to transfer the substrates among the first transfer unit 12, the second transfer unit 21, the chemical mechanical polishing unit 23, and the single chamber cleaning device 24.

The second transfer unit 21 includes a fixed buffer 211 and a moving buffer 212 for temporarily storing the substrate and shipping the substrate. The fixed buffer 211 is provided at a position adjacent to the front end module 1 to temporarily store the substrate transferred from the front end module 1 or the substrate to be transferred to the front end module 1. The movement buffer 212 is provided along the direction from the equipment front end module 1 to the grinding module 3 to form a substrate transfer path between the equipment front end module 1 and the grinding module 3, and substrates are transferred between the equipment front end module 1, the polishing module 2, and the grinding module 3 through the movement buffer 212. The movement buffer unit 212 includes a fixing mechanism, a centering mechanism, and a horizontal movement mechanism, the centering mechanism is provided on the fixing mechanism to position the substrate placed on the fixing mechanism to a position concentric with the fixing mechanism, and the fixing mechanism is connected to the horizontal movement mechanism to horizontally move the fixing mechanism with the substrate loaded thereon. The movable buffer portion 212 is movable in both directions in the horizontal direction, and the movable buffer portion 212 is movable in a forward or reverse direction between a first position close to the fixed buffer portion 211 or the front end module 1 of the apparatus and a second position close to the grinding module 3 to transfer the substrate to the grinding module 3 or receive the substrate transferred from the grinding module 3 and transfer the substrate to another unit. The substrate is taken out from the front end module 1 and then transported to the grinding module 3 via the mobile buffer 212 for grinding; after the substrate is ground in the grinding module 3, the substrate is transported to the chemical mechanical polishing unit 23 in the polishing module 2 via the movement buffer 212 to be polished.

As exemplarily shown in fig. 1 and 2, the moving buffer 212 has only one substrate transfer path, and can only transport the substrate from the first position to the second position or transport the substrate from the second position to the first position. Of course, it is also contemplated that the moving buffer 212 may include a plurality of substrate transfer lanes, thereby enabling simultaneous transport of one substrate from a first location to a second location and transport of another substrate from the second location to the first location. For example, the moving buffer part 212 may include a plurality of moving buffers that are movable bidirectionally, and the plurality of moving buffers may be arranged side by side in a lateral direction or arranged up and down in a vertical direction.

As shown in fig. 7, the third transfer unit 22 includes a dry robot 221 and a wet robot 222. The dry robot 221 may transfer the substrate from the fixed buffer part 211 of the second transfer unit 21 to the moving buffer part 212, and the wet robot 222 may transfer the ground substrate from the moving buffer part 212 to the chemical mechanical polishing unit 23, or transfer the chemical mechanical polished substrate from the chemical mechanical polishing unit 23 to the single chamber cleaning apparatus 24. As in the embodiment shown in fig. 1 and 2, the moving buffer 212 carries both the dry substrate to be ground conveyed from the front end module 1 and the wet substrate after grinding, so that the dry robot 221 is spaced apart from the moving buffer 212 in the vertical direction during the movement of the dry robot 221 above the moving buffer 212, i.e., spaced apart from the moving buffer 212 in the vertical direction, in order to prevent the dry robot 221 from being contaminated by the wet moving buffer, so that the dry robot 221 does not directly contact the moving buffer 212 during the conveyance of the substrate onto the moving buffer 212. In this way, contamination of the dry robot 221 due to the transfer of wet substrates by the moving buffer 212 is avoided. The dry robot 221 and the wet robot 222 are fixed to the same base and can rotate around the base, which can move horizontally.

It will be appreciated that the composition of the third transfer unit 22 is only schematically illustrated in fig. 1 and 2, and in practical applications, the dry robot 221 and the wet robot 222 are at different heights to prevent interference during movement. The dry robot 221 and the wet robot 222 can perform a moving operation between a long distance and a short distance, and the robot arms of the both can be extended to extend an operation distance and can be folded to retract the operation distance.

As shown in fig. 8, Chemical Mechanical Planarization (CMP) is a global surface Planarization technique that can precisely and uniformly planarize a substrate to a desired thickness and flatness. The chemical mechanical polishing unit 23 receives the substrate from the third transfer unit 22 and performs a chemical mechanical polishing process to improve the planarization effect of the substrate. As shown in fig. 1 and 2 and fig. 8, the chemical mechanical polishing unit 23 includes a sheet storing part 231, a polishing disk 232, a polishing pad 233 adhered to the polishing disk 232, two carrier heads 234 that adsorb the substrate and rotate the substrate, a dresser 235 that dresses the polishing pad 232, and a liquid supply part 236 that supplies polishing liquid to the surface of the polishing pad 233, wherein the two carrier heads 234 are respectively located at two semicircular parts of the polishing disk 232 divided along the length direction of the substrate thinning apparatus.

In the present embodiment, the chemical mechanical polishing unit 23 having two carrier heads 234 is adopted, so that the two carrier heads 234 can operate simultaneously, the working efficiency of the polishing module 2 is improved, the waiting time inside the equipment is reduced, and the throughput is improved. It should be noted that the two carrier heads 234 may share a set of upper pneumatic components or upper drive components, and the positional relationship of the two carrier heads is not limited by the positional relationship of fig. 1-3, and fig. 1-3 are merely for purposes of illustrating the feasibility of configuring two carrier heads by way of example.

In particular, the two carrier heads 234 may have the same or different configurations and may have radii greater than or less than the radius of the substrate, and specifically may be greater than 100mm or greater than 150mm, and may be less than 50mm or less than 75mm, wherein for an 8 inch wafer, two different carrier heads may be provided, wherein the radius of the larger radius carrier head is greater than 100mm and the radius of the smaller radius carrier head is less than 50 mm; similarly, for a 12 inch wafer, two different carrier heads may be provided, with the larger radius carrier head having a radius greater than 150mm and the smaller radius carrier head having a radius less than 75 mm.

Before polishing starts, the wet robot 222 of the third transfer unit 22 carries the substrate to the storage section 231, and the carrier head 234 moves from the storage section 231 to above the polishing platen 232 in the radial direction of the polishing platen 232 after loading the substrate thereon. During chemical mechanical polishing, the carrier head 234 presses the substrate against the polishing pad 233 covered by the surface of the polishing pad, and the size of the polishing pad 233 is larger than the size of the substrate to be polished, for example, 1.2 times or more the size of the substrate, thereby ensuring uniform polishing of the substrate. The carrier head 234 performs a rotating motion and reciprocates in a radial direction of the polishing platen 232 so that the surface of the substrate contacting the polishing pad 233 is gradually polished while the polishing platen 232 rotates, and the liquid supply part 236 sprays the polishing liquid onto the surface of the polishing pad 233. The substrate is rubbed against the polishing pad 233 by the relative movement of the carrier head 234 and the polishing platen 232 under the chemical action of the polishing liquid to perform polishing. Polishing liquid consisting of submicron or nanometer abrasive particles and chemical solution flows between a substrate and a polishing pad 233, the polishing liquid is uniformly distributed under the action of transmission and rotating centrifugal force of the polishing pad 233 to form a layer of liquid film between the substrate and the polishing pad 233, chemical components in the liquid and the substrate generate chemical reaction to convert insoluble substances into easily soluble substances, then the chemical reactants are removed from the surface of the substrate through micro-mechanical friction of the abrasive particles and dissolved into the flowing liquid to be taken away, namely surface materials are removed in an alternate process of chemical film forming and mechanical film removing to realize surface planarization treatment, thereby achieving the purpose of global planarization. During polishing, the dresser 235 serves to dress and activate the topography of the polishing pad surface 233. The dresser 235 can remove foreign particles remaining on the surface of the polishing pad, such as abrasive particles in the polishing liquid and waste materials falling off from the surface of the substrate, and can also flatten the surface deformation of the polishing pad 233 caused by the grinding, thereby ensuring the consistency of the surface topography of the polishing pad 233 during the polishing and further stabilizing the polishing removal rate. After the polishing is completed, the carrier head 234 adsorbs the substrate to place it on the storage section 231, and the third transfer unit 22 takes the substrate from the storage section 231 and conveys the substrate to the single chamber cleaning device 24.

Fig. 9 is a schematic structural diagram of a carrier head 234. The carrier head 234 includes an upper structure 2341 coupled to the carrier head drive shaft and a lower structure 2342 coupled by a flexible connection. The substructure 2342 includes a gimbal, a base 2343, a flexible membrane 2344, and a retaining ring 2345. The elastic membrane 2344 and the retaining ring 2345 are both fixed to the lower surface of the base 2343, and the annular retaining ring 2345 is located outside the elastic membrane 2344 and is disposed around the elastic membrane 2344. The elastic membrane 2344 is used to attract and apply a downward force to the substrate, and may be made of an elastic material, for example, chloroprene or silicone rubber. The retaining ring 2345 is used to hold the substrate under the elastic membrane 2344 to prevent the substrate from slipping out. As shown in fig. 9, the elastic membrane 2344 has a plurality of concentric pressure-adjustable chambers therein, and the example of fig. 9 having 5 pressure-adjustable chambers is described, which includes a first chamber Z1, a second chamber Z2, a third chamber Z3, a fourth chamber Z4 and a fifth chamber Z5, which are concentrically arranged from the center to the outside. The central first chamber Z1 is circular and the second to fifth chambers Z2 to Z5 are concentric rings. It is clear that the number of chambers shown in fig. 9 is only an example, and that other numbers, such as six, seven, etc., are possible. Particularly advantageously, the number of pressure-adjustable chambers is seven.

The bottom of the carrier head employed in this embodiment is provided with at least five pressure-adjustable chambers, preferably seven pressure-adjustable chambers, such that the pressure applied to each zone of the substrate surface can be adjusted by controlling the pressure in each pressure-adjustable chamber. The internal pressures of the 1 st chamber Z1 through the fifth chamber Z5 are independent of each other and can be varied, respectively, and accordingly, different chambers of the carrier head divide the surface of the substrate into a corresponding plurality of zones, thereby enabling independent adjustment of the polishing pressures of five concentric annular zones corresponding to the surface of the substrate. Each chamber can apply different pressures to the corresponding substrate surface subarea, and different pressures can be applied to different subareas of the substrate surface by respectively controlling the pressure of fluid such as pressurized air supplied to the chambers. The CMP multi-region pressure intelligent control technology realizes accurate compensation and regulation of the surface shape of the substrate, and effectively improves the overall thickness uniformity of the thinned substrate.

A single-chamber cleaning device 24 (for example, as shown in fig. 1-2) is used for cleaning and drying the polished substrate, the single-chamber cleaning device 24 is disposed between the chemical mechanical polishing unit 23 and the front end module 1 of the apparatus so as to be quickly transported to the front end module 1 of the apparatus for storage after cleaning and drying the polished substrate, and the single-chamber cleaning device 24 is respectively adjacent to the first transport unit 12, the third transport unit 22 and the chemical mechanical polishing unit 23, a first opening and closing window is disposed on a side surface of the single-chamber cleaning device 24 facing the first transport unit 12 so as to facilitate the first transport unit to take and place the substrate into and from the single-chamber cleaning device 24, and a second opening and closing window is disposed on a side surface of the single-chamber cleaning device 24 facing the third transport unit 22 so as to facilitate the third transport unit to take and place the substrate into and place from the single-chamber cleaning device. As shown in FIGS. 1-2, the single chamber wash apparatus 24 is a wash and dry integrated apparatus 24.

As shown in fig. 10, the single chamber cleaning device 24 includes a carrying portion 2411 for holding and rotating the substrate w, a fluid supply portion 2413 (not shown) for ejecting a fluid to the substrate, a shutter portion 2412 for blocking the splashed fluid, and a fluid collection chamber (not shown). The carrier portion 2411, fluid supply portion, and baffle portion 2412 are all disposed within a closed fluid collection chamber to prevent fluid leakage. The bearing portion 2411 keeps the substrate horizontal, and the bearing portion 2411 drives the substrate to rotate around its vertical central axis. The baffle portion 2412 is disposed around the bearing portion 2411, and the baffle portion 2412 may be formed of an annular baffle member. The fluid supply unit is used for spraying cleaning liquid or drying gas on the surface of the substrate, and under different actual requirements, the fluid supply unit can spray water, acid solution and/or alkaline solution, drying gas and the like on the substrate in sequence according to different operation sequences, and different liquid can be guided into different chambers by using different baffles.

The drawings in the present specification are schematic views to assist in explaining the concept of the present invention, and schematically show the shapes of the respective portions and the mutual relationships thereof. It should be understood that the drawings are not necessarily to scale, the same reference numerals being used to identify the same elements in the drawings in order to clearly illustrate the structure of the various elements of the embodiments of the invention.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (8)

1. A substrate thinning apparatus having a chemical mechanical polishing unit, comprising:

the device comprises an equipment front-end module, a grinding module and a polishing module with a chemical mechanical polishing unit;

the chemical mechanical polishing unit includes that one deposits a piece portion, a polishing dish, one bonds the polishing pad on the polishing dish, two are used for adsorbing the base plate and drive the rotatory carrier head of base plate, a trimmer of repairing the polishing pad and provide the confession liquid portion of polishing pad surface earlier on, two carrier heads are located the polishing dish respectively and are followed two semicircle parts that the length direction of base plate attenuate equipment divided.

2. The substrate thinning apparatus of claim 1, wherein the carrier head comprises a plurality of annular, concentric, pressure-adjustable chambers that divide the surface of the substrate into a corresponding plurality of zones, the pressures applied to the plurality of zones being separately adjustable by separately controlling the pressures in the plurality of pressure-adjustable chambers.

3. The substrate thinning apparatus of claim 2, wherein the plurality of adjustable pressure chambers is at least seven.

4. The substrate thinning apparatus of claim 2, wherein the carrier head further comprises:

an upper structure connected with a drive shaft of the carrier head;

a substructure connected to the superstructure by a flexible connection, the substructure comprising:

a balancing stand;

a base;

the elastic membrane is used for adsorbing the substrate and exerting downward pressure on the substrate, the elastic membrane is fixed on the lower surface of the base, and the pressure-adjustable chambers are arranged inside the elastic membrane; and

a retaining ring for retaining the substrate below the elastic membrane to prevent the substrate from slipping out, the retaining ring being fixed on the lower surface of the base and arranged outside the elastic membrane around the elastic membrane, the retaining ring protruding from the elastic membrane in the axial direction.

5. The substrate thinning apparatus according to claim 1, wherein a loading pressure of the carrier head to each zone of the substrate is adjusted according to a thickness distribution of the substrate after completion of grinding and before chemical mechanical polishing.

6. The substrate thinning apparatus according to claim 1, wherein a loading pressure of the carrier head to each zone of the substrate is adjusted according to a thickness distribution of the substrate measured on-line during chemical mechanical polishing of the substrate.

7. The substrate thinning apparatus according to claim 1, wherein the apparatus front end module includes a first transport unit for feeding the substrate into the polishing module or receiving the substrate from the polishing module, the first transport unit including a pick-and-place robot having a base and an extendable or retractable robot arm rotatable on the base, and a first transport rail on which the base is slidably disposed.

8. The substrate thinning apparatus according to claim 1, wherein the apparatus front end module includes a substrate storage unit disposed at a front end side of the substrate thinning apparatus and including a plurality of front opening substrate transport boxes respectively including a front opening container capable of accommodating a substrate and a front opening door structure hermetically connected to an outer wall of the substrate thinning apparatus.

Images