An apparatus for processing a surface of a substrate

Abstract

The invention relates to an apparatus for processing a surface of a substrate (2), the apparatus comprises a transfer robot (15) and at least one reaction chamber (20, 30, 40), the transfer robot (15) comprises a robot arm (3) and an end effector (1) connected to the robot arm (3), the transfer robot (15) is arranged to load the substrate (2) into and out of the at least one reaction chamber (20, 30, 40). The end effector (1) having an support surface (1a) arranged to support the substrate (2) during loading into and out of the reaction chamber (20, 30, 40), and a heat transfer element (4) arranged to heat the substrate (2) through the support surface (1a) of the end effector (1) during the loading.

Description

[0001] AN APPARATUS FOR PROCESSING A SURFACE OF A SUBSTRATE

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to an apparatus for processing a surface of a substrate and more particularly to an apparatus as defined in the preamble of the independent claim 1.

[0004] The present invention also relates to a method for processing a substrate, and more particularly to a method as defined in the preamble of the independent claim 14.

[0005] In particularly, the present invention relates to a semiconductor or wafer processing apparatus, in which separate substrate discs or wafers are processed, and to a method for processing a substrate

[0006] BACKGROUND OF THE INVENTION

[0007] In the prior art, those substrate discs that typically require heating before their surface is processed in a reaction chamber of a wafer processing tool apparatus are heated in a separate heating chamber with 1R -heaters. Alternatively, a heating element for heating the substrate is provided in a processing chamber if that is possible.

[0008] One of the problems associated with the prior art is that sometimes the reaction chambers cannot be equipped with heaters or separate heating chambers require too much space or make the process system too complicated.

[0009] BRIEF DESCRIPTION OF THE INVENTION

[0010] An object of the present invention is to provide an apparatus which alleviates the problems of the prior art so that substrate can be heated without a separate heating chamber or which can be heated outside the reaction chamber.

[0011] The objects of the invention are achieved by an apparatus and a method which are characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

[0012] The invention is based on the idea of providing a transfer robot which comprises an end effector arranged to move the substrate and to load it into the reaction chamber. The end effector is also arranged to heat the substrate so that when the substrate is placed inside the reaction chamber it is already heated. So, the invention is based on the idea of providing a heated end effector, which can be used to heat the substrate wafer and which can also transfer the substrate wafer into the reaction chamber for processing. In this application the word substrate refers to a substrate wafer or a substrate disc or any other single substrate which can be moved separately with an end effector. However, the reaction chamber can process a batch of substrate at the same time, so it is not limited to one substrate. An end effector is a platform tool that is attached to the end of a transfer robot's arm to interact with at least one reaction chamber in such a way that it transfers substrates from the previous process step to the reaction chamber. The previous process step can be for example another chamber or a substrate stack.

[0013] The apparatus for processing a surface of a substrate according to the invention comprises a transfer robot and at least one reaction chamber. The transfer robot comprises a robot arm and an end effector connected to the robot arm. The transfer robot is arranged to load the substrate into and out of the at least one reaction chamber. The end effector has an support surface arranged to support the substrate, and a heat transfer element arranged to heat the substrate provided on the support surface . The heat transfer element may heat the substrate during movement or while in place. Therefore, the heat transfer element of the end effector is arranged to heat the substrate during loading, or unloading, or while in place, or during all or part of these steps.

[0014] In other words, the support surface of the end effector provides a place for the substrate when the transfer robot moves the substrate into the reaction chamber and again out from the reaction chamber after being processed in the reaction chamber. The support surface supports the substrate when it is moved by the transfer robot. The support surface naturally supports the substrate when it is in place either before or after moving it to the reaction chamber. The end effector comprises a heat transfer element which is arranged to the end effector such that the heat generated by the heat transfer element heats the substrate. The substrate lying on the support surface of the end effector is heated through the support surface of the end effector.

[0015] According to the invention the heat transfer element is arranged on the opposite side of the support surface of the end effector on which the substrate is placed, to heat the substrate through the support surface. Alternatively, the heat transfer element is arranged on the opposite side of the support surface of the end effector on which the substrate is placed and housed inside the end effector between the support surface of the end effector and a lower surface of the end effector, to heat the substrate through the support surface.

[0016] In other words, the heat transfer element is arranged on the other side of the support surface such that there is the support surface of the end effector between the substrate and the heat transfer element. This means that the end effector may only be formed as a thin element forming the support surface for the substrate and a heat transfer element is connected or attached to the opposite surface of the end effector than the support surface so that the heat transfer element is not in direct contact with the substrate placed on the support surface. Alternatively, the heat transfer element is arranged on the other side of the support surface and embedded inside the end effector so that the heat transfer element is not in direct contact with the substrate placed on the support surface.

[0017] According to the invention the heat transfer element is arranged to form the end effector and the substrate is placed on the heat transfer element forming the support surface.

[0018] In other words, the heat transfer element forms the end effector so that the substrate support is also made of the heat transfer element. This means that the substrate placed on the substrate support is in direct contact with the heat transfer element.

[0019] According to the invention the support surface of the end effector forms a planar support surface for the substrate such that the substrate is in surface contact with the support surface of the end effector when placed on the end effector.

[0020] In other words, the support surface is planar and extends as a uniform support surface so that the substrate placed on the support surface is supported throughout by the support surface.

[0021] According to the invention the planar support surface is a flat surface so that the substrate placed on the end effector is in contact with the support surface of the end effector throughout on the planar support surface.

[0022] In other words, the support surface is preferably such that it provides a maximum contact with the substrate placed on the support surface leaving no space between the substrate and the support surface.

[0023] According to the invention the end effector further comprises one or more thermocouples for measuring temperature.

[0024] In other words, the end effector comprises at least one temperature measurement sensor which is arranged to provide temperature data. Although, the temperature measurement sensor is referred as a thermocouple also other types of temperature measurement sensors are possible to measure the temperature of the end effector and / or the substrate placed on the support surface of the end effector. Therefore, in this application the term thermocouple also includes other temperature sensors.

[0025] According to the invention the one or more thermocouples are arranged to the support surface of the end effector such that the one or more thermocouples are arranged to measure the temperature of the substrate placed on the support surface of the end effector. Alternatively, the one or more thermocouples are arranged to the support surface of the end effector such that the one or more thermocouples are arranged to measure the temperature of the support surface of the end effector. Alternatively, the one or more thermocouples are arranged to the support surface of the end effector such that the one or more thermocouples are arranged to measure the temperature of the substrate placed on the support surface of the end effector and the temperature of the support surface of the end effector.

[0026] In other words, the one or more thermocouples or one or more temperature sensors are arranged to the end effector so that the temperature of the end effector and / or the substrate placed on the support surface of the end effector can be measured. The thermocouple preferably measures the temperature of the support surface of the end effector so that the temperature can be adjusted to a desired temperature for the substrate. The thermocouple or the temperature sensor is preferably arranged to extend from inside of the end effector to the support surface of the end effector.

[0027] Further in other words, the one or more thermocouples are arranged to extend from inside the end effector to the support surface of the end effector so that the one or more thermocouples are arranged to measure the temperature of the substrate provided on the support surface and the temperature of the support surface itself. The one or more thermocouples therefore provide two different temperature measurements so that both the temperature of the substrate and the temperature of the support surface of the end effector can be separately determined, allowing for more precise temperature control of the heat transfer element in the end effector based on the temperature measurements of the support surface and the substrate.

[0028] In an embodiment of the invention the thermocouples are provided in the end effector so that they extend from the inside of the end effector toward the support surface through drilling holes provided in the body of the end effector so that tips of the thermocouples come into contact with the substrate when it has been placed on the support surface. This allows to measure the exact temperature of the substrate. In other words, the end effector comprises holes which extend from inside of the end effector to the support surface of the end effector and are provided with thermocouples or other temperature sensors. The holes are preferably drilling holes.

[0029] According to the invention at least one of the thermocouples is provided on the edge region of the support surface of the end effector.

[0030] In other words, at least one of the thermocouples is arranged to measure the substrate temperature from the edge of the substrate, therefore the at least one thermocouple is arranged at a distance from the centre of the support surface which is closer to the edge of the support surface than to the centre of the support surface. In other words, the edge region of the substrate support is the area that is closer to the outer perimeter of the substrate support than the center of the substrate support.

[0031] According to the invention at least one of the thermocouples is provided at the centre of the support surface of the end effector.

[0032] According to the invention the end effector comprises at least one stopper to prevent the substrate from sliding away from the support surface of the end effector.

[0033] In other words, the end effector comprises a stopper, which can be. for example, a pin or a tongue, which is arranged, for example, on the perimeter of the end effector or the support surface of the end effector in such a way that the substrate cannot slide off the support surface so that it drips from the end effector, but which also does not prevent the substrate from being placed in the reaction chamber on the substrate holders so that the substrate remains on the holders, but the end effector can be taken out of the reaction chamber.

[0034] According to the invention the support surface of the end effector comprises a circular shape.

[0035] In other words, the support surface which is arranged to support the substrate during loading to the reaction chamber and unloading from the reaction chamber is circular, meaning that the support surface may be almost a full circle or oval or elliptical.

[0036] According to the invention the support surface of the end effector is made of heat conductive material having thermal conductivity at least 14 Wm-i K-1. The heat conductive material can be for example aluminum or aluminum alloys, silver or silver alloys, copper or copper alloys, gold or gold alloys, beryllium or beryllium alloys, tungsten or tungsten alloys, graphite, magnesium or magnesium alloys, silicon or silicon alloys, zinc or zinc alloys, nickel or nickel alloys or stainless steel.

[0037] According to a preferable embodiment of the invention the support surface of the end effector is made of heat conductive material having thermal conductivity at least 200 W nr1K-1. The heat conductive material being aluminum or aluminum alloys.

[0038] In other words, the material of the support surface of the end effector is made of good thermal conductor which is clean room compatible, and therefore aluminum or aluminum alloy is good option for the material. The end effector can be made entirely from the same material.

[0039] According to the invention the heat transfer element is arranged to heat the support surface of the end effector for transferring heat from the heat transfer element through the support surface of the end effector to the substrate by conduction.

[0040] In other words, the heat transfer element is arranged in the end effector such that there is no direct contact between the heat transfer element and the substrate placed on the support surface but the heat is transferred from the heat transfer element to the substrate through the support surface by conduction. This means that there is no direct physical contact between the substrate and the heat transfer element, but the heat is transferred through a physical contact between the support surface and the substrate, and the support surface is heated by the heat transfer element.

[0041] According to the invention the heat transfer element comprises a resistor wire, or a ceramic resistor, or electrical resistance heater, or a selfregulating heater, an induction heating element, or a combination of these.

[0042] The heat transfer element can be for example a PTC (Positive Temperature Coefficient) heater, a ceramic heater, a resistance heater, a quartz heater, a micathermic heater, an infrared heater (carbon and / or halogen) or an inductive heating.

[0043] Method for processing a substrate in an wafer processing apparatus having a transfer robot and at least one reaction chamber, the transfer robot comprising a robot arm and an end effector connected to the robot arm according to the invention comprises the steps of placing the substrate on an support surface of the end effector, heating the substrate placed on the support surface of the end effector with a heat transfer element provided in the end effector, moving the substrate placed on the support surface of the end effector with the transfer robot into and out of the reaction chamber.

[0044] In the step of heating the substrate, the heating is performed by conduction from the heat transfer element in connection with the end effector via the support surface of the end effector on which the substrate is placed.

[0045] The method according to the invention is carried out with the apparatus according to what is described in this application.

[0046] An advantage of the invention is that by heating the substrate before processing the substrate in the reaction chamber, the processing time is reduced since the loading and heating can be combined together or the heating can be performed outside the reaction chamber. The performance of the apparatus is also increased because the reaction chamber can be used solely for processing the substrate without the need to heat the substrate separately in the reaction chamber anymore. An advantage is also that the user of the apparatus can monitor the temperature of the heated end effector by the thermocouples allowing to set different temperature set points for different substrate wafers and processes. The user can also monitor the temperature of the substrate wafer itself during the transfer to and from the reaction chamber.

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The invention is described in detail by means of specific embodiments with reference to the enclosed drawings, in which

[0049] Figure 1 shows an apparatus according to the invention;

[0050] Figure 2 shows another embodiment of an apparatus according to the invention;

[0051] Figures 3a and 3b show embodiments of an end effector as seen from above; and

[0052] Figures 4a, 4b, and 4c show embodiments of an end effector as a cut-out view from side.

[0053] DETAILED DESCRIPTION OF THE INVENTION

[0054] Figure 1 shows an apparatus for processing a substrate 2. The apparatus comprises a transfer robot 15 and at least one reaction chamber 20. The transfer robot 15 and the reaction chamber 20 are preferably provided in a vacuum space 60. The transfer robot 15 comprises a robot arm 3 and an end effector 1 connected to the robot arm 3. The transfer robot 15 is arranged to load the substrate 2 into and out of the reaction chamber 20. The transfer robot 15 is movable with the end effector 1 such that it picks the substrate 2, carries the substrate 2 into the reaction chamber 20 and leaves the substrate on substrate holders in the reaction chamber 20 and thereafter moves out from the reaction chamber 20. The end effector 1 of the transfer robot 15 moves such that the substrate 2 remains in a horizontal direction on the end effector 1. After the substrate 2 has been processed in the reaction chamber 20 the end effector 1 picks up the substrate 2 from the reaction chamber 20 and carries it to the next place.

[0055] Figure 2 shows another embodiment of an apparatus according to the invention in which the transfer robot 15 is provided in a cluster apparatus comprising multiple chambers 20, 30, 40, 50. The cluster apparatus 1 comprises a transfer chamber 10 which has a vacuum atmosphere inside the transfer chamber 10 provided by a vacuum device (not shown in the figure) or works under atmospheric pressure. The transfer robot 15 is arranged inside the transfer chamber 10. The cluster apparatus 1 further comprises a substrate reactor 20 connected to the transfer chamber 10 via a transfer connection 25 via which a substrate is loaded on the substrate reactor 20 and unloaded from there, and with which the substrate reactor 20 is opened and closed. The transfer connection 25 may comprise for example a gate valve. The cluster apparatus 1 further comprises subsequent substrate reactors 30, 40, 50 connected to the transfer chamber 10 via subsequent transfer connections 35, 45, 55 via which a substrate is loaded on the subsequent substrate reactor 30, 40, 50 and unloaded from there, and with which the subsequent substrate reactor 30, 40, 50 is opened and closed. The subsequent transfer connections 35, 45, 55 may comprise for example a gate valve. A vacuum device is arranged to provide vacuum to the chambers.

[0056] Figure 3a shows an end effector 1 as seen from above. The end effector 1 has a support surface la which supports the substrate 2 during loading and unloading it. The end effector 1 is preferably a circular or round in shape and has an even surface. Also, other shapes such as rectangular, triangular or elliptical shapes are possible. The support surface la comprises at least one thermocouple 5 for measuring temperature of the support surface la and / or the substrate 2. Figure 3 shows an end effector 1 having four thermocouples 5 from which one is provided at the centre of the end effector 1 and three of them are provided on the edge region of the support surface la.

[0057] Figure 3b shows an end effector 1 as seen from above, which comprises the heat transfer element 4 as part of the support surface la. The support surface la of the end effector 1 supports the substrate 2 and the substrate 2 comes into a direct contact with the heat transfer element 4 while on the support surface lc. The end effector 1 is preferably a circular or round in shape and has an even surface. Similarly, as in the embodiment shown in figure 3a, the support surface la comprises at least one thermocouple 5 for measuring temperature of the support surface la and / or the substrate 2. The heat transfer element 4 may form the entire support surface la of the end effector 1 or only part of it as shown in figure 3b.

[0058] Figure 4a shows an end effector 1 as a cut-out view from side. The end effector 1 has a heat transfer element 4 arranged inside the end effector 1 so that it heats the substrate 2 through the support surface la by conduction. In other words, the heat transfer element 4 is embedded in the end effector 1 between the support surface la and the lower surface lb opposite the support surface la. The end effector 1 extends away from the arm 3 of the transfer robot 15. The end effector 1 preferably comprises a stopper 6 to prevent the substrate 2 from sliding away from the support surface la of the end effector 1. An embodiment of the stopper 6 in figure 4 is a pin arrangement on the edge of the end effector 1. Other solutions of the stopper are also possible. The end effector further comprises thermocouples 5 that extend from inside the end effector 1 to the support surface la to measure the temperature of the substrate 2 or the support surface la or both.

[0059] Figure 4b shows an embodiment of an end effector 1 which is otherwise similar to that shown in figure 4a but without the stopper 6. The support surface la may be provided with a friction-increasing coating or it may otherwise have properties which prevent substrate 2 from falling out from the support surface la during movement of the end effector 1.

[0060] Figure 4c shows an embodiment of an end effector 1 having a support surface la on which the substrate 2 is placed. On the other side of the end effector 1, i.e., on opposite side than the support surface la is a heat transfer element 4 attached to the end effector 1. The heat transfer element 4 is arranged to heat the substrate 2 through the end effector 1 so that the support surface la heats up and heats the substrate 2 through conduction.

[0061] The invention has been described above with reference to the examples shown in the figures. However, the invention is in no way restricted to the above examples but may vary within the scope of the claims.

Claims

CLAIMS1. Apparatus for processing a surface of a substrate (2), the apparatus comprises a transfer robot (15) and at least one reaction chamber (20, 30, 40), the transfer robot (15) comprises a robot arm (3) and an end effector (1) connected to the robot arm (3), the transfer robot (15) is arranged to load the substrate (2) into and out of the at least one reaction chamber (20, 30, 40), characterized in that the end effector (1) having a support surface (la) arranged to support the substrate (2), and a heat transfer element (4) arranged to heat the substrate (2) provided on the support surface (la).

2. Apparatus according to claim 1, characterized in that the heat transfer element (4) is arranged on the opposite side of the support surface (la) of the end effector (1) on which the substrate (2) is placed, to heat the substrate (2) through the support surface (la), or the heat transfer element (4) is arranged on the opposite side of the support surface (la) of the end effector (1) on which the substrate (2) is placed and housed inside the end effector (1) between the support surface (la) of the end effector (1) and a lower surface (lb) of the end effector (1), to heat the substrate (2) through the support surface (la).

3. Apparatus according to claim 1, characterized in that the heat transfer element (4) is arranged to form at least part of the support surface (la) of the end effector (1) on which the substrate (2) is placed.

4. Apparatus according to claim 1, characterized in that the heat transfer element (4) is arranged to form the end effector (1) and the substrate (2) is placed on the heat transfer element (4) forming the support surface (la).

5. Apparatus according to any previous claim, characterized in that the support surface (la) of the end effector (1) forms a planar support surface for the substrate (2) such that the substrate (2) is in a surface contact with the support surface (la) of the end effector (1) when placed on the end effector (1).

6. Apparatus according to any previous claim, characterized in that the end effector (1) further comprises one or more thermocouples (5) formeasuring temperature.

7. Apparatus according to claim 6, characterized in that the one or more thermocouples (5) are arranged to the support surface (la) of the end effector (1) such that: the one or more thermocouples (5) are arranged to measure the temperature of the substrate (2) placed on the support surface (la) of the end effector (1), or the one or more thermocouples (5) are arranged to measure the temperature of the support surface (la) of the end effector (1), or the one or more thermocouples (5) are arranged to measure the temperature of the substrate (2) placed on the support surface (la) of the end effector (1) and the temperature of the support surface (la) of the end effector (1).

8. Apparatus according to claim 7, characterized in that at least one of the thermocouples (5) is provided on the edge region of the support surface (la) of the end effector (1).

9. Apparatus according to claim 7 or 8, characterized in that at least one of the thermocouples (5) is provided at the centre of the support surface (la) of the end effector (1).

10. Apparatus according to any previous claim, characterized in that the support surface (la) of the end effector (1) comprises a circular shape.

11. Apparatus according to any previous claim, characterized in that the support surface (la) of the end effector (1) is made of heat conductive material having thermal conductivity at least 14 W nr1K-1.

12. Apparatus according to any previous claim, characterized in that the heat transfer element (4) is arranged to heat the support surface (la) of the end effector (1) for transferring heat from the heat transfer element (4) through the support surface (la) of the end effector (1) to the substrate (2) by conduction.

13. Apparatus according to any previous claim, characterizedin that the heat transfer element (4) comprises a resistor wire, or a ceramic resistor, or electrical resistance heater, or a self-regulating heater, an induction heating element, or a combination of these.

14. Method for processing a substrate (2) in a wafer processing apparatus having a transfer robot (15) and at least one reaction chamber (20, 30, 40), the transfer robot (15) comprising a robot arm (3) and an end effector (1) connected to the robot arm (3), characterized in that the method comprises the steps of: placing the substrate (2) on an support surface (la) of the end effector Cl), heating the substrate (2) placed on the support surface (la) of the end effector (1) with a heat transfer element (4) provided in the end effector (1), and moving the substrate (2) placed on the support surface (la) of the end effector (1) with the transfer robot (15) into and out of the reaction chamber (20, 30, 40).

15. Method according to claim 14, characterized in that the method is carried out with the apparatus according to any of claims 1-13.

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