EP4306262A1 - Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate - Google Patents
Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate Download PDFInfo
- Publication number
- EP4306262A1 EP4306262A1 EP22184834.4A EP22184834A EP4306262A1 EP 4306262 A1 EP4306262 A1 EP 4306262A1 EP 22184834 A EP22184834 A EP 22184834A EP 4306262 A1 EP4306262 A1 EP 4306262A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- polishing
- cloth
- plate
- polishing plate
- spacers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
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- 238000005498 polishing Methods 0.000 title claims abstract description 192
- 239000004065 semiconductor Substances 0.000 title claims abstract description 24
- 235000012431 wafers Nutrition 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000004744 fabric Substances 0.000 claims abstract description 111
- 125000006850 spacer group Chemical group 0.000 claims abstract description 32
- 238000003825 pressing Methods 0.000 claims abstract description 23
- 239000012790 adhesive layer Substances 0.000 claims abstract description 10
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 6
- 238000004026 adhesive bonding Methods 0.000 claims abstract 3
- 241001295925 Gegenes Species 0.000 description 4
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000003292 glue Substances 0.000 description 2
- 238000005096 rolling process Methods 0.000 description 2
- 239000004698 Polyethylene Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000002759 woven fabric Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
- B24B37/07—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool
- B24B37/08—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool for double side lapping
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D9/00—Wheels or drums supporting in exchangeable arrangement a layer of flexible abrasive material, e.g. sandpaper
- B24D9/08—Circular back-plates for carrying flexible material
- B24D9/085—Devices for mounting sheets on a backing plate
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B7/00—Machines or devices designed for grinding plane surfaces on work, including polishing plane glass surfaces; Accessories therefor
- B24B7/10—Single-purpose machines or devices
- B24B7/16—Single-purpose machines or devices for grinding end-faces, e.g. of gauges, rollers, nuts, piston rings
- B24B7/17—Single-purpose machines or devices for grinding end-faces, e.g. of gauges, rollers, nuts, piston rings for simultaneously grinding opposite and parallel end faces, e.g. double disc grinders
Definitions
- the subject of the invention is a method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate.
- Polishing workpieces such as semiconductor wafers on both sides is also called double-side polishing (DSP).
- DSP double-side polishing
- Basics of the DSP of semiconductor wafers are, for example, in US 2003 0 054 650 A1 and in DE 100 07 390 A1 described.
- both polishing plates of a DSP system are covered with polishing cloths. These should be glued on without bubbles. It is important that the respective polishing cloth adheres evenly to the polishing plate. In order to achieve the necessary adhesion, the polishing cloths can be pressed together between the polishing plates (cloth pressing). Pressing causes the glue to flow and adhere better.
- Methods for creating an adhesive connection between the respective polishing cloth and the corresponding polishing plate are out US 2007 0 087 671 A1 , JP 2006 289 523 A , JP 2006 346 808 A and DE 102 39 774 A1 known.
- EP 4 000 806 A1 describes a method that uses an intermediate ring to temporarily glue the upper polishing cloth to the upper polishing plate in the area of the surface of the intermediate ring in a more adhesive manner than in adjacent areas.
- the inventors of the invention described below have found that there is still a need for improvement because the use of an intermediate ring has not proven to be sufficiently reliable in allowing bubbles to form between the upper polishing pad and the upper polishing cloth can be easily pressed, in particular, to the inner edge of the upper polishing cloth and removed there, without risking that the adhesion of the upper polishing cloth to the upper polishing plate is lost.
- spacers instead of an intermediate ring results in an intermediate state being achieved for pressing the upper polishing cloth against the upper polishing plate, in which the upper polishing cloth adheres reliably to the upper polishing plate, but still loose enough to prevent bubbles mechanically from the space between the upper polishing cloth and the upper polishing plate. Because the intermediate pieces are not connected to one another, the path along which a bubble is pressed out of the intermediate space can be radial, leading to the inner edge or the outer edge of the polishing cloth if necessary also have tangential parts.
- the spacers are used instead of an intermediate ring to achieve the intermediate state, the area of the upper polishing cloth that adheres comparatively firmly to the upper polishing cloth is lower and therefore the risk that bubbles will be trapped that cannot be removed or can only be removed with difficulty.
- the space between the spacers is used to drive bubbles to the inner edge or outer edge of the upper polishing cloth and eliminate them there.
- spacers instead of an intermediate ring also reduces the risk of the upper polishing cloth becoming detached from the upper polishing plate after reaching the intermediate state. This danger exists because, on the one hand, the pressure with which the upper polishing plate is pressed against the lower polishing plate must not be too high due to the potential formation of bubbles, but on the other hand it must be sufficient to hold the upper polishing cloth on the upper polishing plate.
- the scope available for choosing the right print is machine-dependent and narrow. If spacers are used instead of an intermediate ring, this clearance is greater.
- the spacers are placed on an intermediate cloth so that they lie concentrically to the inner edge of the lower polishing cloth and at approximately the same distance from one another on the intermediate cloth.
- the distance between the spacers and the inner edge of the lower polishing plate is preferably 0 mm to 5 mm.
- the spacers lie on an annular surface with a radial width of preferably 10 mm to 100 mm, particularly preferably 30 mm to 50 mm.
- the degree of coverage of the annular surface by the spacers is preferably 1% to 15%, particularly preferably 3% to 10%.
- the spacers are preferably not less than 100 ⁇ m and not more than 300 ⁇ m thick. They preferably have the shape of triangles, in particular isosceles or equilateral triangles. Other shapes are also possible, for example the shape of other polygons or circles or semicircles.
- the spacers are preferably made of a plastic, for example polyethylene.
- the polishing cloths are ring-shaped and each include a side surface with an adhesive layer.
- the lower polishing cloth is glued to the lower polishing plate.
- the lower polishing cloth is pressed against the lower polishing plate pressed manually or by a machine.
- at least one tool is used to press the lower polishing cloth against the lower polishing plate.
- the tool is preferably a squeegee or a roller.
- the direction of the tool movement is preferably radial and, if necessary, also tangential, in order to press bubbles out of the space between the lower polishing plate and the adhesive layer by applying pressure, preferably on the outer edge and/or on the inner edge of the lower polishing cloth.
- the lower polishing cloth is then covered with an intermediate cloth.
- the intermediate cloth preferably has the in DE 10 2017 217 490 A1 properties described, in particular a compressibility at room temperature of at least 3%, preferably 3% to 10%.
- a first and a second intermediate cloth can also be placed on the lower polishing cloth.
- the spacers are then placed on the intermediate cloth so that they lie concentrically to the inner edge of the lower polishing cloth and at approximately the same distance from one another on the intermediate cloth.
- the upper polishing cloth is placed over the intermediate cloth and over the spacers so that the side surface with the adhesive layer faces the upper polishing plate.
- the upper polishing plate is then pressed against the lower polishing plate and this state is maintained for a certain period of time. Because of the presence of the spacers, the upper polishing cloth is pressed against the upper polishing plate with higher pressure in the area of the spacers than in the adjacent areas. After subsequently removing the spacers and the intermediate cloth, the intermediate state then achieved ensures sufficient adhesion of the upper polishing cloth to the upper polishing plate. At the same time, it also makes it possible in the next step to reliably press bubbles over the areas with less pronounced adhesion to the upper polishing plate to the outer edge and/or inner edge of the upper polishing cloth with comparatively little effort. This is preferably done manually using a tool, such as a squeegee or a roller. The direction of the tool movement is preferably radial and, if necessary, also tangential in order to press bubbles out of the space between the upper polishing plate and the adhesive layer by applying pressure on the outer edge and/or on the inner edge of the upper polishing cloth.
- Cloth pressing is then carried out, during which the upper polishing plate and the upper polishing cloth are pressed against the lower polishing plate and the lower polishing cloth with comparatively high pressure over a longer period of time. If two intermediate cloths were placed on the lower polishing cloth, the lower one of the intermediate cloths remains between the polishing plates when the cloth is pressed and is only removed afterwards.
- the polishing plates have a temperature of 40 ° C to 50 ° C at the beginning of cloth pressing in order to reduce the viscosity of the adhesive of the adhesive layer, according to another embodiment, room temperature (23 ° C ⁇ 2 ° C).
- the method according to the invention is continued with the polishing of semiconductor wafers on both sides in the presence of a polishing agent.
- the DSP is preferably carried out with process parameters that are already in DE 10 2017 217 490 A1 are recommended. Some of these are mentioned again below.
- the use of polishing cloths that have low or very low compressibility is preferred.
- the compressibility of the respective polishing cloth is preferably not more than 2.5%, particularly preferably not more than 2.0%, determined at room temperature (23 ° C ⁇ 2 ° C).
- the compressibility is determined analogously to JIS-L-1096 (Testing Methods for Woven Fabrics).
- the thickness of the polishing cloths is preferably not less than 0.7 and not more than 1.5 mm.
- the semiconductor wafers are each placed in a recess in a rotor disk that is dimensioned according to their circumference.
- the semiconductor wafers preferably consist of single-crystalline silicon and preferably have a diameter of not less than 200 mm, particularly preferably a diameter of at least 300 mm.
- the polishing agent is expediently a suspension which preferably contains colloidally disperse silica and optionally other compounds, for example those which adjust the pH.
- the material removal by DSP is preferably not more than 15 ⁇ m, particularly preferably 5 ⁇ m to 12 ⁇ m per polished side surface.
- Fig. 1 shows the basic structure of a DSP machine: A lower, ring-shaped polishing plate 12 and an upper polishing plate 13 rotate on collinear axes 9 and 10 with rotational speeds n o and n u .
- An inner pin ring 6 is arranged within the inner diameter of the polishing plates 13 and 12 and an outer pin ring 20 is arranged outside the outer diameter of the annular polishing plates 12 and 13, which are collinear with rotational speeds n i and n a to the polishing plates and thus around the common axis 11 of the DSP -Machine rotate.
- the inner pin ring 6 and the outer pin ring 20 form a rolling device in which, for example, three or five rotor disks 15 with suitable external teeth are inserted.
- the rotor disks 15 each have at least one or more disk holders 2 for semiconductor disks 14.
- the lower polishing plate 12 and the upper polishing plate 13 carry a lower polishing cloth 19 and an upper polishing cloth 16, respectively, on their mutually facing surfaces.
- the mutually facing surfaces of the lower and upper polishing cloths 19 and 16 form lower and upper work surfaces, respectively. During processing, these come into contact with the front and back of the semiconductor wafers 14.
- the rotor disks 15 with the semiconductor disks 14 are guided simultaneously over the lower and upper work surfaces on cycloidal paths, with the rotor disks 15 rotating around the axis 11 on planetary paths.
- the space formed between the working surfaces in which the rotor disks 15 move is referred to as the working gap 17.
- the upper polishing plate 13 exerts a force on the lower polishing plate 12, and a polishing agent is supplied via channels 18 in the upper polishing plate 13.
- the DSP machine can have sensors 3 and 4, which are arranged at different radial positions, for example in the upper polishing plate 13, and which measure the distance between the mutually facing surfaces of the polishing plates 12 and 13 during the polishing of semiconductor wafers 14.
- Fig. 2 shows a top view of the lower polishing plate 12 at the time after spacers 1 have been placed on an intermediate cloth 7, so that they lie concentrically to the inner edge 5 of the lower polishing cloth 19 and at approximately the same distance from one another on the intermediate cloth 7.
- Fig. 3 shows a sectional view of the vertical arrangement of features during the pressing of the upper polishing plate 13 against the lower polishing plate 12 and before the removal of the intermediate cloth 7 and the spacers 1.
- the spacers 1 lie on the intermediate cloth 7 and between the lower and upper polishing cloths 19, 16, which are pressed against each other.
- the upper polishing cloth 16 is glued to the upper polishing plate 13 using the adhesive layer 8. The pressure with which this happens is higher in the areas of the spacers 1 than in their surroundings.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
Abstract
Verfahren zum beidseitigen Polieren von Halbleiterscheiben zwischen einem unteren Polierteller und einem oberen Polierteller mittels eines unteren und eines oberen Poliertuchs, die jeweils einen Innenrand und einen Außenrand aufweisen, umfassenddas Bekleben des unteren Poliertellers mit dem unteren Poliertuch;das Pressen des unteren Poliertuchs gegen den unteren Polierteller;das Ablegen von Halbleiterscheiben auf dem unteren Poliertuch; unddas beidseitige Polieren der Halbleiterscheiben in Gegenwart eines Poliermittels; gekennzeichnet durchdas Abdecken des unteren Poliertuchs mit einem Zwischentuch nach dem Pressen des unteren Poliertuchs gegen den unteren Polierteller und vor dem Ablegen der Halbleiterscheiben auf dem unteren Poliertuch;das Ablegen von Distanzstücken auf das Zwischentuch, so dass sie konzentrisch zum Innenrand des unteren Poliertuchs und in annähernd gleichem Abstand zueinander auf dem Zwischentuch liegen;das Ablegen des oberen Poliertuchs über das Zwischentuch und über die Distanzstücke, wobei das obere Poliertuch mit einer zum oberen Polierteller weisenden klebenden Schicht versehen ist;das Pressen des oberen Poliertellers gegen den unteren Polierteller;das Entfernen des Zwischentuchs und der Distanzstücke;das Pressen des oberen Poliertuchs gegen den oberen Polierteller; unddas Pressen der Polierteller und Poliertücher gegeneinander.Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate by means of a lower and an upper polishing cloth, each of which has an inner edge and an outer edge, comprising gluing the lower polishing plate with the lower polishing cloth; pressing the lower polishing cloth against the lower polishing plate ;placing semiconductor wafers on the lower polishing cloth; andpolishing the semiconductor wafers on both sides in the presence of a polishing agent; characterized bycovering the lower polishing cloth with an intermediate cloth after pressing the lower polishing cloth against the lower polishing plate and before placing the semiconductor wafers on the lower polishing cloth;placing spacers on the intermediate cloth so that they are concentric with the inner edge of the lower polishing cloth and in approximately lie on the intermediate cloth at the same distance from each other; placing the upper polishing cloth over the intermediate cloth and over the spacers, whereby the upper polishing cloth is provided with an adhesive layer facing the upper polishing plate; pressing the upper polishing plate against the lower polishing plate; removing the intermediate cloth and the spacers;pressing the upper polishing cloth against the upper polishing plate; andpressing the polishing plates and polishing cloths against each other.
Description
Gegenstand der Erfindung ist ein Verfahren zum beidseitigen Polieren von Halbleiterscheiben zwischen einem unteren Polierteller und einem oberen Polierteller.The subject of the invention is a method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate.
Das beidseitige Polieren von Werkstücken wie Halbleiterscheiben wird auch Doppelseitenpolitur (DSP) genannt. Grundzüge der DSP von Halbleiterscheiben sind beispielsweise in
In der Regel werden beide Polierteller einer DSP-Anlage mit Poliertüchern beklebt. Diese sollten blasenfrei aufgeklebt sein. Dabei ist es wichtig, dass das jeweilige Poliertuch auf dem Polierteller gleichmäßig stark haftet. Um die notwendige Haftung zu erreichen, können die Poliertücher zwischen den Poliertellern zusammengepresst werden (Tuchpressen). Durch das Pressen verfließt der Kleber und haftet besser. Verfahren zum Schaffen einer klebenden Verbindung zwischen dem jeweiligen Poliertuch und dem entsprechenden Polierteller sind aus
In
Die Erfinder der nachstehend beschriebenen Erfindung haben festgestellt, dass weiterhin Bedarf an einer Verbesserung besteht, weil das Verwenden eines Zwischenrings sich als nicht ausreichend zuverlässig erwiesen hat, zu ermöglichen, dass Blasen zwischen dem oberen Polierteller und dem oberen Poliertuch auf einfache Weise insbesondere zum Innenrand des oberen Poliertuchs gedrückt und dort entfernt werden können, ohne dabei zu riskieren, dass die Haftung des oberen Poliertuchs auf dem oberen Polierteller verloren geht.The inventors of the invention described below have found that there is still a need for improvement because the use of an intermediate ring has not proven to be sufficiently reliable in allowing bubbles to form between the upper polishing pad and the upper polishing cloth can be easily pressed, in particular, to the inner edge of the upper polishing cloth and removed there, without risking that the adhesion of the upper polishing cloth to the upper polishing plate is lost.
Die Aufgabe der Erfindung wird gelöst durch ein Verfahren zum beidseitigen Polieren von Halbleiterscheiben zwischen einem unteren Polierteller und einem oberen Polierteller mittels eines unteren und eines oberen Poliertuchs, die jeweils einen Innenrand und einen Außenrand aufweisen, umfassend
- das Bekleben des unteren Poliertellers mit dem unteren Poliertuch;
- das Pressen des unteren Poliertuchs gegen den unteren Polierteller;
- das Ablegen von Halbleiterscheiben auf dem unteren Poliertuch; und
- das beidseitige Polieren der Halbleiterscheiben in Gegenwart eines Poliermittels; gekennzeichnet durch
- das Abdecken des unteren Poliertuchs mit einem Zwischentuch nach dem Pressen des unteren Poliertuchs gegen den unteren Polierteller und vor dem Ablegen der Halbleiterscheiben auf dem unteren Poliertuch;
- das Ablegen von Distanzstücken auf das Zwischentuch, so dass sie konzentrisch zum Innenrand des unteren Poliertuchs und in annähernd gleichem Abstand zueinander auf dem Zwischentuch liegen;
- das Ablegen des oberen Poliertuchs über das Zwischentuch und über die Distanzstücke, wobei das obere Poliertuch mit einer zum oberen Polierteller weisenden klebenden Schicht versehen ist;
- das Pressen des oberen Poliertellers gegen den unteren Polierteller;
- das Entfernen des Zwischentuchs und der Distanzstücke;
- das Pressen des oberen Poliertuchs gegen den oberen Polierteller; und
- das Pressen der Polierteller und Poliertücher gegeneinander.
- sticking the lower polishing cloth on the lower polishing plate;
- pressing the lower polishing cloth against the lower polishing plate;
- placing semiconductor wafers on the lower polishing cloth; and
- polishing the semiconductor wafers on both sides in the presence of a polishing agent; marked by
- covering the lower polishing cloth with an intermediate cloth after pressing the lower polishing cloth against the lower polishing plate and before placing the semiconductor wafers on the lower polishing cloth;
- placing spacers on the intermediate cloth so that they are concentric with the inner edge of the lower polishing cloth and at approximately the same distance from one another on the intermediate cloth;
- placing the upper polishing cloth over the intermediate cloth and over the spacers, the upper polishing cloth being provided with an adhesive layer facing the upper polishing plate;
- pressing the upper polishing plate against the lower polishing plate;
- removing the intermediate cloth and spacers;
- pressing the upper polishing cloth against the upper polishing plate; and
- pressing the polishing plates and polishing cloths against each other.
Das Verwenden von Distanzstücken anstelle eines Zwischenrings führt dazu, dass für das Pressen des oberen Poliertuchs gegen den oberen Polierteller ein Zwischenzustand erreicht wird, in dem das obere Poliertuch auf dem oberen Polierteller zuverlässig haftet, aber dennoch lose genug, um Blasen mechanisch aus dem Zwischenraum zwischen dem oberen Poliertuch und dem oberen Polierteller drücken zu können. Wegen der fehlenden Verbindung der Zwischenstücke zueinander kann der Weg, auf dem eine Blase aus dem Zwischenraum gedrückt wird, radiale, zum Innenrand oder zum Außenrand des Poliertuchs führende Anteile und nötigenfalls auch tangentiale Anteile haben. Wenn anstelle eines Zwischenrings Distanzstücke verwendet werden, um den Zwischenzustand zu erreichen, ist die Fläche des oberen Poliertuchs, die vergleichsweise fest auf dem oberen Poliertuch haftet geringer und damit auch das Risiko, dass Blasen eingeschlossen werden, die sich nicht oder nur schwer beseitigen lassen. Der Zwischenraum zwischen den Distanzstücken wird genutzt, um Blasen bis zum Innenrand oder zum Außenrand des oberen Poliertuchs zu treiben und dort zu beseitigen.The use of spacers instead of an intermediate ring results in an intermediate state being achieved for pressing the upper polishing cloth against the upper polishing plate, in which the upper polishing cloth adheres reliably to the upper polishing plate, but still loose enough to prevent bubbles mechanically from the space between the upper polishing cloth and the upper polishing plate. Because the intermediate pieces are not connected to one another, the path along which a bubble is pressed out of the intermediate space can be radial, leading to the inner edge or the outer edge of the polishing cloth if necessary also have tangential parts. If spacers are used instead of an intermediate ring to achieve the intermediate state, the area of the upper polishing cloth that adheres comparatively firmly to the upper polishing cloth is lower and therefore the risk that bubbles will be trapped that cannot be removed or can only be removed with difficulty. The space between the spacers is used to drive bubbles to the inner edge or outer edge of the upper polishing cloth and eliminate them there.
Die Verwendung von Distanzstücken anstelle eines Zwischenrings verringert auch die Gefahr, dass das obere Poliertuch nach Erreichen des Zwischenzustands sich vom oberen Polierteller löst. Diese Gefahr besteht, weil der Druck, mit dem der obere Polierteller gegen den unteren Polierteller gedrückt wird, wegen der potenziellen Blasenbildung einerseits nicht zu hoch sein darf, andererseits aber ausreichen muss, das obere Poliertuch auf dem oberen Polierteller zu halten. Der Spielraum, der für die Wahl des passenden Drucks zur Verfügung steht, ist maschinenabhängig und eng. Werden Distanzstücke anstelle eines Zwischenrings verwendet, ist dieser Spielraum größer.The use of spacers instead of an intermediate ring also reduces the risk of the upper polishing cloth becoming detached from the upper polishing plate after reaching the intermediate state. This danger exists because, on the one hand, the pressure with which the upper polishing plate is pressed against the lower polishing plate must not be too high due to the potential formation of bubbles, but on the other hand it must be sufficient to hold the upper polishing cloth on the upper polishing plate. The scope available for choosing the right print is machine-dependent and narrow. If spacers are used instead of an intermediate ring, this clearance is greater.
Die Distanzstücke werden auf ein Zwischentuch gelegt, so dass sie konzentrisch zum Innenrand des unteren Poliertuchs und in annähernd gleichem Abstand zueinander auf dem Zwischentuch liegen. Der Abstand der Distanzstücke zum Innenrand des unteren Poliertellers beträgt vorzugsweise 0 mm bis 5 mm. Die Distanzstücke liegen auf einer ringförmigen Fläche mit einer radialen Breite von vorzugsweise 10 mm bis 100 mm, besonders bevorzugt 30 mm bis 50 mm. Der Bedeckungsgrad der ringförmigen Fläche durch die Distanzstücke beträgt vorzugsweise 1 % bis 15 %, besonders bevorzugt 3 % bis 10 %. Die Distanzstücke sind vorzugsweise nicht weniger als 100 µm und nicht mehr als 300 µm dick. Sie haben vorzugsweise die Form von Dreiecken, insbesondere von gleichschenkeligen oder gleichseitigen Dreiecken. Andere Formen sind auch möglich, beispielsweise die Form anderer Polygone oder von Kreisen oder Halbkreisen. Die Distanzstücke bestehen vorzugsweise aus einem Kunststoff, beispielsweise aus Polyethylen.The spacers are placed on an intermediate cloth so that they lie concentrically to the inner edge of the lower polishing cloth and at approximately the same distance from one another on the intermediate cloth. The distance between the spacers and the inner edge of the lower polishing plate is preferably 0 mm to 5 mm. The spacers lie on an annular surface with a radial width of preferably 10 mm to 100 mm, particularly preferably 30 mm to 50 mm. The degree of coverage of the annular surface by the spacers is preferably 1% to 15%, particularly preferably 3% to 10%. The spacers are preferably not less than 100 µm and not more than 300 µm thick. They preferably have the shape of triangles, in particular isosceles or equilateral triangles. Other shapes are also possible, for example the shape of other polygons or circles or semicircles. The spacers are preferably made of a plastic, for example polyethylene.
Die Poliertücher sind ringförmig ausgebildet und umfassen jeweils eine Seitenfläche mit einer klebenden Schicht. Zunächst wird das untere Poliertuch auf den unteren Polierteller geklebt. Danach wird das untere Poliertuch gegen den unteren Polierteller manuell oder durch eine Maschine gepresst. Gemäß einer Ausführungsform wird mindestens ein Werkzeug verwendet, um das untere Poliertuch gegen den unteren Polierteller zu pressen. Das Werkzeug ist vorzugsweise eine Rakel oder eine Walze. Die Richtung der Werkzeugbewegung ist vorzugsweise radial und nötigenfalls zweitweise auch tangential, um Blasen mittels Druckausübung vorzugsweise am Außenrand und/oder am Innenrand des unteren Poliertuchs aus dem Zwischenraum zwischen dem unteren Polierteller und der klebenden Schicht zu drücken.The polishing cloths are ring-shaped and each include a side surface with an adhesive layer. First, the lower polishing cloth is glued to the lower polishing plate. Then the lower polishing cloth is pressed against the lower polishing plate pressed manually or by a machine. According to one embodiment, at least one tool is used to press the lower polishing cloth against the lower polishing plate. The tool is preferably a squeegee or a roller. The direction of the tool movement is preferably radial and, if necessary, also tangential, in order to press bubbles out of the space between the lower polishing plate and the adhesive layer by applying pressure, preferably on the outer edge and/or on the inner edge of the lower polishing cloth.
Danach wird das untere Poliertuch mit einem Zwischentuch abgedeckt. Das Zwischentuch hat vorzugsweise die in
Anschließend werden die Distanzstücke auf das Zwischentuch gelegt, so dass sie konzentrisch zum Innenrand des unteren Poliertuchs und in annähernd gleichem Abstand zueinander auf dem Zwischentuch liegen.The spacers are then placed on the intermediate cloth so that they lie concentrically to the inner edge of the lower polishing cloth and at approximately the same distance from one another on the intermediate cloth.
Im nächsten Schritt wird das obere Poliertuch über das Zwischentuch und über die Distanzstücke gelegt und zwar so, dass die Seitenfläche mit der klebenden Schicht zum oberen Polierteller weist.In the next step, the upper polishing cloth is placed over the intermediate cloth and over the spacers so that the side surface with the adhesive layer faces the upper polishing plate.
Daraufhin wird der obere Polierteller gegen den unteren Polierteller gepresst und dieser Zustand eine gewisse Zeit aufrechterhalten. Wegen der Anwesenheit der Distanzstücke wird das obere Poliertuch im Bereich der Distanzstücke mit höherem Druck gegen den oberen Polierteller gedrückt, als in den angrenzenden Bereichen. Nach dem nachfolgenden Entfernen der Distanzstücke und des Zwischentuchs sorgt der dann erreichte Zwischenzustand für ausreichend Haftung des oberen Poliertuchs am oberen Polierteller. Gleichzeitig ermöglicht er es auch, dass im nächsten Schritt Blasen mit vergleichsweise geringem Aufwand zuverlässig über die Bereiche mit weniger ausgeprägter Haftung zum oberen Polierteller zum Außenrand und/oder Innenrand des oberen Poliertuchs gedrückt werden können. Das geschieht vorzugsweise manuell mit Hilfe eines Werkzeugs, beispielsweise einer Rakel oder einer Walze. Die Richtung der Werkzeugbewegung ist vorzugsweise radial und nötigenfalls zweitweise auch tangential, um Blasen mittels Druckausübung am Außenrand und/oder am Innenrand des oberen Poliertuchs aus dem Zwischenraum zwischen dem oberen Polierteller und der klebenden Schicht zu drücken.The upper polishing plate is then pressed against the lower polishing plate and this state is maintained for a certain period of time. Because of the presence of the spacers, the upper polishing cloth is pressed against the upper polishing plate with higher pressure in the area of the spacers than in the adjacent areas. After subsequently removing the spacers and the intermediate cloth, the intermediate state then achieved ensures sufficient adhesion of the upper polishing cloth to the upper polishing plate. At the same time, it also makes it possible in the next step to reliably press bubbles over the areas with less pronounced adhesion to the upper polishing plate to the outer edge and/or inner edge of the upper polishing cloth with comparatively little effort. This is preferably done manually using a tool, such as a squeegee or a roller. The direction of the tool movement is preferably radial and, if necessary, also tangential in order to press bubbles out of the space between the upper polishing plate and the adhesive layer by applying pressure on the outer edge and/or on the inner edge of the upper polishing cloth.
Danach wird ein Tuchpressen vorgenommen, im Zuge dessen der obere Polierteller und das obere Poliertuch über einen längeren Zeitraum gegen den unteren Polierteller und das untere Poliertuch mit vergleichsweise hohem Druck gepresst wird. Wurden zwei Zwischentücher auf das untere Poliertuch gelegt, bleibt das untere der Zwischentücher beim Tuchpressen zwischen den Poliertellern und wird erst danach entfernt.Cloth pressing is then carried out, during which the upper polishing plate and the upper polishing cloth are pressed against the lower polishing plate and the lower polishing cloth with comparatively high pressure over a longer period of time. If two intermediate cloths were placed on the lower polishing cloth, the lower one of the intermediate cloths remains between the polishing plates when the cloth is pressed and is only removed afterwards.
Gemäß einer Ausgestaltung der Erfindung haben die Polierteller zu Beginn des Tuchpressens eine Temperatur von 40 °C bis 50 °C, um die Viskosität des Klebers der klebenden Schicht zu verringern, gemäß einer anderen Ausgestaltung Raumtemperatur (23 °C ± 2 °C).According to one embodiment of the invention, the polishing plates have a temperature of 40 ° C to 50 ° C at the beginning of cloth pressing in order to reduce the viscosity of the adhesive of the adhesive layer, according to another embodiment, room temperature (23 ° C ± 2 ° C).
Nach dem blasenfreien Anbringen der Poliertücher und gegebenenfalls nach einem Abrichten (Dressing) der Poliertücher wird das erfindungsgemäße Verfahren mit dem beidseitigen Polieren von Halbleiterscheiben in Gegenwart eines Poliermittels fortgesetzt. Vorzugsweise erfolgt die DSP mit Prozessparametern, die bereits in
Bevorzugt ist die Verwendung von Poliertüchern, die eine geringe oder sehr geringe Kompressibilität aufweisen. Bevorzugt beträgt die Kompressibilität des jeweiligen Poliertuches nicht mehr als 2,5%, besonders bevorzugt nicht mehr als 2,0%, ermittelt bei Raumtemperatur (23 °C ± 2 °C). Die Bestimmung der Kompressibilität erfolgt analog zur JIS-L-1096 (Testing Methods for Woven Fabrics).The use of polishing cloths that have low or very low compressibility is preferred. The compressibility of the respective polishing cloth is preferably not more than 2.5%, particularly preferably not more than 2.0%, determined at room temperature (23 ° C ± 2 ° C). The compressibility is determined analogously to JIS-L-1096 (Testing Methods for Woven Fabrics).
Die Dicke der Poliertücher beträgt vorzugsweise nicht weniger als 0,7 und nicht mehr als 1,5 mm.The thickness of the polishing cloths is preferably not less than 0.7 and not more than 1.5 mm.
Zum Polieren werden die Halbleiterscheiben jeweils in eine entsprechend deren Umfang dimensionierte Aussparung einer Läuferscheibe gelegt. Die Halbleiterscheiben bestehen vorzugsweise aus einkristallinem Silizium und haben vorzugsweise einen Durchmesser von nicht weniger als 200 mm, besonders bevorzugt einen Durchmesser von mindestens 300 mm.For polishing, the semiconductor wafers are each placed in a recess in a rotor disk that is dimensioned according to their circumference. The semiconductor wafers preferably consist of single-crystalline silicon and preferably have a diameter of not less than 200 mm, particularly preferably a diameter of at least 300 mm.
Das Poliermittel ist zweckmäßigerweise eine Suspension, die vorzugsweise kolloiddisperse Kieselsäure und gegebenenfalls weitere Verbindungen, beispielsweise solche, die den pH-Wert einstellen, enthält.The polishing agent is expediently a suspension which preferably contains colloidally disperse silica and optionally other compounds, for example those which adjust the pH.
Der Materialabtrag durch DSP beträgt vorzugsweise nicht mehr als 15 µm, besonders bevorzugt 5 µm bis 12 µm je polierter Seitenfläche.The material removal by DSP is preferably not more than 15 µm, particularly preferably 5 µm to 12 µm per polished side surface.
Einzelheiten zur Erfindung werden nachfolgend unter Bezugnahme auf Zeichnungen erläutert.Details of the invention are explained below with reference to drawings.
-
Fig. 1 zeigt in perspektivischer Darstellung typische Merkmale einer DSP-Maschine.Fig. 1 shows typical features of a DSP machine in a perspective view. -
Fig. 2 zeigt eine Draufsicht auf den unteren Polierteller.Fig. 2 shows a top view of the lower polishing plate. -
Fig. 3 zeigt in Schnittdarstellung die vertikale Anordnung von Merkmalen.Fig. 3 shows the vertical arrangement of features in a sectional view.
- 11
- DistanzstückeSpacers
- 22
- ScheibenaufnahmeDisc recording
- 33
- Sensorsensor
- 44
- Sensorsensor
- 55
- InnenrandInner edge
- 66
- innerer Stiftkranzinner pin wreath
- 77
- ZwischentuchIntermediate cloth
- 88th
- klebende Schichtadhesive layer
- 99
- Achseaxis
- 1010
- Achseaxis
- 1111
- Achseaxis
- 1212
- unterer Poliertellerlower polishing plate
- 1313
- oberer Poliertellerupper polishing plate
- 1414
- Halbleiterscheibensemiconductor wafers
- 1515
- LäuferscheibenRotor disks
- 1616
- oberes Poliertuchtop polishing cloth
- 1717
- Arbeitsspaltworking gap
- 1818
- Kanälechannels
- 1919
- unteres Poliertuchlower polishing cloth
- 2020
- äußerer Stiftkranzouter pin wreath
- 2121
- AußenrandOuter edge
Der untere Polierteller 12 und der obere Polierteller 13 tragen auf ihren einander zugewandten Oberflächen ein unteres Poliertuch 19 beziehungsweise ein oberes Poliertuch 16. Die einander zugewandten Oberflächen des unteren und oberen Poliertuchs 19 und 16 bilden untere beziehungsweise obere Arbeitsflächen. Diese gelangen während der Bearbeitung in Kontakt mit Vorder- und Rückseite der Halbleiterscheiben 14.The
Mittels der Abwälzvorrichtung und der Außenverzahnung werden die Läuferscheiben 15 mit den Halbleiterscheiben 14 auf zykloidischen Bahnen gleichzeitig über die untere und obere Arbeitsfläche geführt, wobei die Läuferscheiben 15 auf Planetenbahnen um die Achse 11 umlaufen. Der zwischen den Arbeitsflächen gebildete Raum, in dem sich die Läuferscheiben 15 bewegen, wird als Arbeitsspalt 17 bezeichnet. Während der Bearbeitung übt der obere Polierteller 13 eine Kraft auf den unteren Polierteller 12 aus, und es wird über Kanäle 18 im oberen Polierteller 13 ein Poliermittel zugeführt. Die DSP-Maschine kann Sensoren 3 und 4 aufweisen, die an unterschiedlichen Radialpositionen beispielsweise im oberen Polierteller 13 angeordnet sind und die während des Polierens von Halbleiterscheiben 14 den Abstand der einander zugewandten Oberflächen der Polierteller 12 und 13 messen.By means of the rolling device and the external toothing, the
Claims (4)
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EP22184834.4A EP4306262A1 (en) | 2022-07-13 | 2022-07-13 | Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate |
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EP22184834.4A EP4306262A1 (en) | 2022-07-13 | 2022-07-13 | Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate |
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Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10007390A1 (en) | 1999-03-13 | 2000-10-12 | Wolters Peter Werkzeugmasch | Dual disc polishing apparatus for semiconductor wafer, has support base which is connected with drive shaft and support disc, so that inclination of upper and lower grinding discs are equal |
US20030054650A1 (en) | 2001-07-05 | 2003-03-20 | Wacker Siltronic Gesellschaft Fur Halbleitermaterialien Ag | Process for material-removing machining of both sides of semiconductor wafers |
DE10239774A1 (en) | 2002-08-29 | 2003-11-27 | Wacker Siltronic Halbleitermat | Method and apparatus for attaching polishing cloths to the plates of a polishing machine such as for polishing silicon wafers using grooves or ridges to control application of a vacuum |
JP2006289523A (en) | 2005-04-06 | 2006-10-26 | Speedfam Co Ltd | Double sided polishing device equipped with pressure roller for applying polishing pad, and applying method of polishing pad |
JP2006346808A (en) | 2005-06-15 | 2006-12-28 | Mimasu Semiconductor Industry Co Ltd | Grinding pad sticking method and workpiece producing method |
US20070087671A1 (en) | 2005-10-17 | 2007-04-19 | Fujikoshi Machinery Corp. | Method of adhering polishing pads and jig for adhering the same |
DE102017217490A1 (en) | 2017-09-29 | 2019-04-04 | Siltronic Ag | Method for polishing both sides of a semiconductor wafer |
DE102019213657A1 (en) * | 2019-09-09 | 2021-03-11 | Siltronic Ag | Method and device for pressing a polishing cloth |
WO2021235050A1 (en) * | 2020-05-19 | 2021-11-25 | 信越半導体株式会社 | Method for affixing polishing pad of double-sided polishing device |
EP4000806A1 (en) | 2020-11-16 | 2022-05-25 | Siltronic AG | Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate |
EP4000802A1 (en) * | 2020-11-17 | 2022-05-25 | Siltronic AG | Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate |
-
2022
- 2022-07-13 EP EP22184834.4A patent/EP4306262A1/en active Pending
Patent Citations (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10007390A1 (en) | 1999-03-13 | 2000-10-12 | Wolters Peter Werkzeugmasch | Dual disc polishing apparatus for semiconductor wafer, has support base which is connected with drive shaft and support disc, so that inclination of upper and lower grinding discs are equal |
US20030054650A1 (en) | 2001-07-05 | 2003-03-20 | Wacker Siltronic Gesellschaft Fur Halbleitermaterialien Ag | Process for material-removing machining of both sides of semiconductor wafers |
DE10239774A1 (en) | 2002-08-29 | 2003-11-27 | Wacker Siltronic Halbleitermat | Method and apparatus for attaching polishing cloths to the plates of a polishing machine such as for polishing silicon wafers using grooves or ridges to control application of a vacuum |
JP2006289523A (en) | 2005-04-06 | 2006-10-26 | Speedfam Co Ltd | Double sided polishing device equipped with pressure roller for applying polishing pad, and applying method of polishing pad |
JP2006346808A (en) | 2005-06-15 | 2006-12-28 | Mimasu Semiconductor Industry Co Ltd | Grinding pad sticking method and workpiece producing method |
US20070087671A1 (en) | 2005-10-17 | 2007-04-19 | Fujikoshi Machinery Corp. | Method of adhering polishing pads and jig for adhering the same |
DE102017217490A1 (en) | 2017-09-29 | 2019-04-04 | Siltronic Ag | Method for polishing both sides of a semiconductor wafer |
DE102019213657A1 (en) * | 2019-09-09 | 2021-03-11 | Siltronic Ag | Method and device for pressing a polishing cloth |
WO2021235050A1 (en) * | 2020-05-19 | 2021-11-25 | 信越半導体株式会社 | Method for affixing polishing pad of double-sided polishing device |
EP4000806A1 (en) | 2020-11-16 | 2022-05-25 | Siltronic AG | Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate |
EP4000802A1 (en) * | 2020-11-17 | 2022-05-25 | Siltronic AG | Method for polishing semiconductor wafers on both sides between a lower polishing plate and an upper polishing plate |
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