In-situ wired wafer thin film temperature sensor

Abstract

The application provides an in-situ wafer film temperature sensor for measuring the temperature of a wafer (1), characterized in that at least comprising a film temperature sensor (2), a film lead wire (3) and a lead wire, the film temperature sensor (2) is connected to the film lead wire (3), the film lead wire (3) is connected to the lead wire, and at least the film temperature sensor (2) and the film lead wire (3) are arranged on the wafer (1). The sensor provided by the application is integrally attached on the wafer, is fixed firmly, and does not have the lead wire shaking phenomenon of the existing wafer temperature measuring sensor.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of semiconductor equipment, in particular, to the field of semiconductor wafer detection and temperature measurement, and relates to a wafer temperature sensor, in particular, to an in-situ wired wafer thin film temperature sensor, which can be used to measure the temperature distribution of a semiconductor processing machine in a vacuum chamber. BACKGROUND

[0002] In the process of semiconductor manufacturing, such as lithography, dry etching, ion implantation, diffusion, dry strip, wet clean, mask, chemical vapor deposition, physical vapor deposition, chemical mechanical polishing, etc., almost all process steps require strict temperature measurement and control.

[0003] An in-situ wafer temperature sensor is a tool for measuring temperature and other physical quantities in the actual working environment, including the actual working process of the reaction chamber, during chip manufacturing process, and is an indispensable system calibration tool in semiconductor equipment manufacturing and semiconductor production process.

[0004] The existing in-situ wired wafer temperature sensor, as described in patents US6190040 and US6915589, includes a temperature sensor on a wafer, a connecting lead, a lead fixing member, a vacuum through belt, and an interface. The temperature sensor, such as a thermocouple or a thermal resistor, is used as a temperature measuring element or is embedded in a blind hole on the wafer, or is directly adhered to the wafer by a high-temperature resistant adhesive. Each temperature sensor needs an independent lead to be drawn out, and is pressed on the wafer by a metal fixing member at one end of the wafer. The lead of the sensor is made by hand, and in the case of a large number of temperature measuring points, the production is time-consuming, and the leads are easy to overlap with each other. The lead is fixed at both ends and suspended in the middle, and is easy to shake. In the process of using technologies such as thermal radiation heating, if the lead blocks the temperature measuring point, it will greatly affect the accuracy of temperature measurement. According to the production process requirements of semiconductor manufacturing, the in-situ wafer temperature sensor will be subjected to high temperature or low temperature treatment, and the adhesive pasted on the wafer is easy to fall off, the adhesive strength of the temperature sensor and the tensile strength of the lead are poor, and the temperature sensor is easy to be pulled off by human during use.

[0005] In view of the quality problems and cost problems of the existing in-situ wired wafer temperature sensor, a new in-situ wired wafer temperature sensor is needed. SUMMARY

[0006] In order to solve the quality problem of the in-situ wired wafer temperature sensor in the prior art, the application provides a novel in-situ wired wafer temperature sensor for measuring the temperature of a wafer 1, characterized in that it comprises at least a thin-film temperature sensor 2, a thin-film lead 3 and a lead, the thin-film temperature sensor 2 is connected to the thin-film lead 3, the thin-film lead 3 is connected to the lead, and at least the thin-film temperature sensor 2 and the thin-film lead 3 are arranged on the wafer 1.

[0007] Preferably, at least the thin-film temperature sensor 2 and the thin-film lead 3 are arranged in a groove on the wafer 1.

[0008] Preferably, a part of the lead is arranged in the groove on the wafer 1, and the other end of the lead extends out of the wafer 1.

[0009] Preferably, at least a part of the groove is covered with a cover sheet.

[0010] Preferably, the thickness of the cover sheet is smaller than the depth of the groove.

[0011] Preferably, the cover sheet is covered with high-temperature glue for assisting in fixing the cover sheet.

[0012] Preferably, the cover sheet is made of the same material as the wafer 1.

[0013] Preferably, the groove on the wafer 1 is generated in any one of the following ways:

[0014] - dry etching;

[0015] - wet etching;

[0016] - laser slotting; or

[0017] - precision mechanical processing.

[0018] Preferably, the sensor provided by the application further comprises a connector 4, the thin-film lead 3 is connected to the connector 4, and the connector 4 is connected to the lead.

[0019] Preferably, the thin-film temperature sensor 2 is a thermocouple or a thermal resistor.

[0020] Preferably, the thin-film temperature sensor 2 is formed by physical vapor deposition or chemical vapor deposition on the wafer.

[0021] Preferably, the lead comprises a high-temperature lead and a low-temperature lead, and the low-temperature lead is located away from the wafer 1.

[0022] Preferably, the high-temperature lead is platinum rhodium, nickel chromium or nickel aluminum alloy.

[0023] Preferably, the high-temperature lead is provided with an insulating layer of ceramic or quartz material outside.

[0024] Preferably, the low-temperature lead is a copper wire, an enameled wire, a cable or a shielded wire.

[0025] Preferably, the lead further comprises an interface, one end of which is connected to the low-temperature lead, and the other end of which is used for connecting an external device to transmit temperature information.

[0026] Preferably, the lead further comprises a vacuum through belt, which is located between the high-temperature lead and the low-temperature lead, and the high-temperature lead and the low-temperature lead are connected after being respectively inserted into the vacuum through belt.

[0027] Preferably, the thickness of the vacuum through belt is not greater than 0.2 mm.

[0028] Preferably, the vacuum through belt is composed of polyimide.

[0029] Preferably, the thin-film lead 3 is a metal wire deposited on the wafer by vacuum plating.

[0030] Preferably, the material of the thin-film lead 3 is gold, copper or silver.

[0031] Preferably, the sensor provided by the present application further comprises at least one insulating layer, which is arranged in the groove, and at least the thin-film temperature sensor 2 and the thin-film lead 3 are arranged on the insulating layer.

[0032] Preferably, a protective layer or an insulating layer is further deposited above at least the thin-film temperature sensor 2 and the thin-film lead 3.

[0033] Preferably, the connector comprises a fine lead and a protective glue, and the fine lead is used for connecting at least the thin-film lead 3.

[0034] Compared with the existing scheme, the present application uses a thin-film device and a lead to replace the sensor and the lead on the wafer, the sensor provided by the present application is integrally attached to the wafer, is fixed firmly and will not have the lead shaking phenomenon of the existing wafer temperature sensor. By the technical means provided by the present application, the thin-film deposition process is mature, and the production is convenient and the cost is small. BRIEF DESCRIPTION OF DRAWINGS

[0035] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the following drawings:

[0036] Figure 1A , Figure 1BFig. 1 shows a top view and a side view of an in-situ wired wafer thin film temperature sensor according to one embodiment of the present application;

[0037] Figure 2 Fig. 4 shows a schematic diagram of a thin film temperature sensor and a lead wire at a connector area according to one embodiment of the present application;

[0038] Figure 3 Fig. 5 shows a mask diagram for fabricating a thin film temperature sensor and a lead wire according to one embodiment of the present application;

[0039] Figure 4 Fig. 6 shows a schematic diagram of a thin film thermocouple and a thin film thermistor according to one embodiment of the present application.

[0040] BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 1. wafer;

[0042] 2. thin film temperature sensor;

[0043] 3. thin film lead wire;

[0044] 4. connector;

[0045] 5. high temperature lead wire;

[0046] 6. vacuum through strap;

[0047] 7. low temperature lead wire;

[0048] 8. connection port;

[0049] 9. insulating layer;

[0050] 10. protective layer;

[0051] 21. thin film thermocouple anode;

[0052] 22. thin film thermocouple cathode;

[0053] 23. thin film thermocouple temperature measurement point;

[0054] 24. thin film thermistor; 41. thin lead wire; 42. adhesive; 101. sensor mask; 102. lead wire mask. DETAILED DESCRIPTION

[0055] The skilled in the art understand that the technical problem to be solved by the present application is to point out the design defects of the existing in-situ wafer temperature sensor in the background art, and propose a thin film type in-situ wafer temperature sensor, that is, a temperature sensor and a sensor lead are directly made on the wafer by using the method of thin film deposition, there is no suspended lead on the wafer, which avoids the risk of lead shielding heat source and components being pulled off. Compared with the traditional sensor, the thin film type temperature sensor is smaller in size, only a few microns in thickness, has smaller heat capacity and faster temperature response; the existing wafer temperature sensor has multiple leads thicker than the wafer on the wafer, and the thin film type wafer temperature sensor has a thickness close to that of the wafer, which makes it suitable for semiconductor processing cavities and can more truly measure the in-situ wafer temperature in a compact process cavity.

[0056] Figure 1A and Figure 1B The schematic diagram of the in-situ wired wafer thin film temperature sensor is drawn together, wherein Figure 1A is a top view, Figure 1B is a side view. For the convenience of description, the corresponding description and identification of the two figures are given to understand the positional relationship and structural relationship. Preferably, the in-situ wafer thin film temperature sensor provided by the present application comprises a wafer 1, a thin film temperature sensor 2, a thin film lead 3, a connector 4, and a lead. The lead can preferably include any one or more of a high-temperature lead 5, a vacuum through belt 6, a low-temperature lead 7 and an interface 8, and further the skilled in the art understand that any of the above high-temperature lead 5, vacuum through belt 6, low-temperature lead 7 and interface 8 can be selected and combined according to specific factual needs, which is within the scope of the present application. Further, the skilled in the art understand that the lead described in Figure 1A and Figure 1B is not identified in the form of a diagram, wherein the combination of the high-temperature lead 5, the vacuum through belt 6, the low-temperature lead 7 and the interface 8 can be preferably understood as the lead, so as to be understood by the skilled in the art.

[0057] The wafer 1 is used as a raw material for semiconductor processing and manufacturing, and can be a single crystal silicon wafer, a sapphire wafer, a quartz wafer, a ceramic wafer, etc. The size of the wafer 1 can vary from 1 to 12 inches according to different embodiments. The shape of the wafer 1 can be circular and square according to different embodiments. Further, the skilled in the art understand that the wafer 1 is preferably the temperature measurement object, and the thin film temperature sensor 2 is preferably used to measure the temperature of the wafer 1.

[0058] The thin film temperature sensor 2 can be selected from resistance (RTD), thermocouple (TC) according to different embodiments, wherein the resistance thin film temperature sensor 2 can be further divided into negative temperature coefficient (NTC) thermistor and positive temperature coefficient (PTC) platinum resistor. According to different embodiments, the type of the thermocouple can be selected from S, R, B, N, K, E, J, T and the like, and the K, R and B types are preferred. The thermal resistor is preferably a platinum thermal resistor Pt100 or Pt1000. According to different embodiments, the thermocouple or thermal resistor can be deposited on a wafer by vacuum plating, such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), and the corresponding material is deposited, such as nickel-chromium and nickel-aluminum alloy for K-type thermocouple and metal platinum for platinum thermal resistor.

[0059] The number of the thin film temperature sensor 2 can be Figure 1A The number of the thin film temperature sensor 2 can be

[0060] The thin film lead 3 is preferably a metal wire deposited on a wafer by vacuum plating, and can be made of conductive materials such as gold, copper and silver or materials corresponding to the type of thermocouple, such as nickel-chromium and nickel-aluminum alloy for K-type thermocouple, which is used to connect the thin film temperature sensor 2 and the connector 4.

[0061] Preferably, the connector 4 is used to connect the thin film lead 3 and the wafer external lead.

[0062] The high-temperature lead 5 is used to connect the thin film lead 3 on the wafer in a high-temperature environment, and can be made of high-temperature resistant metals such as platinum rhodium, nickel-chromium and nickel-aluminum alloy of the same material of thermocouple, and the outer insulation layer can be a sleeve or fiber tube made of ceramic or quartz material.

[0063] The vacuum through belt 6 is used to pass through the O-shaped sealing ring on the vacuum chamber, and in a preferred embodiment, the thickness is <0.2mm, and further preferably the thickness is 0.1mm. The selected material is polyimide (PI). The structure can be a flexible printed circuit board, or a sandwich structure in the form of PI tape-lead-PI tape. For devices that do not require vacuum and can work in atmospheric environment, the vacuum through belt can not be used.

[0064] The low-temperature lead 7 is used in a low-temperature environment or outside the vacuum chamber, and can be made of copper wire, enameled wire, cable and shielded wire according to different embodiments.

[0065] The interface 8 is used to connect the host computer and transmit temperature signals, and can be made of DB, SCSI, 2-pin interface, LEMO interface and the like according to different embodiments.

[0066] Figure 2A schematic view of the thin film temperature sensor 2 and the lead 3 in the area of the connector 4 is shown.

[0067] As a preferred embodiment, the thin film temperature sensor 2 is connected to the lead 3, and the lead 3 is connected to the lead 5 through a thin lead 41. The thin lead 41 can be gold or aluminum wire, and the thin film lead 3 and the wafer external lead 5 can be connected by using an ultrasonic bonder. Preferably, a protective adhesive 42 is applied at the connection location, and high-temperature-resistant ceramic adhesive or the like can be used according to different embodiments.

[0068] Optionally, an insulating layer 9, such as SiO2or SiN, is deposited between the wafer 1 and the temperature sensor 2 and the thin film lead 3, for electrical insulation between the wafer and the temperature sensor and the thin film lead.

[0069] Optionally, a protective layer 10 is further deposited above the temperature sensor 1 and the thin film lead 2, for protection of the temperature sensor and the thin film lead. The protective layer 10 can use the same material as the insulating layer 9 or the same material as the wafer 1.

[0070] Further, the thin film temperature sensor 2 and the thin film lead 3 can be made using a photolithography process, such as first spin-coating a layer of photoresist on the wafer, using a photomask to shield the non-exposed positions, and exposing, baking, and developing the areas where the sensor and the lead are to be made, and then depositing the thin film sensor and lead materials by vacuum plating, and finally removing the remaining photoresist.

[0071] A hollowed-out mask can also be directly attached to the wafer for vacuum plating. As an embodiment, Figure 3 A schematic view of a mask for making the thin film temperature sensor and the lead is shown. The sensor mask 101 and the lead mask 102 have patterned grooves for the thin film sensor and the thin film lead, respectively, and are placed above the wafer 1 before vacuum plating. The material to be evaporated passes through the hollowed-out patterned grooves of the mask to be deposited on the wafer 1, and the areas without grooves block the deposition of the thin film on the wafer 1.

[0072] As an embodiment, Figure 4 A schematic view of two types of thin film temperature sensors, a thin film thermocouple, and a thin film thermistor is shown. The thin film thermocouple is composed of a thin film thermocouple anode 21 and a thin film thermocouple cathode 22. The manufacturing process can first deposit the anode / cathode thin film material through a mask, then deposit the other pole material, and make the two thin films overlap each other at the temperature measurement point to form a thin film thermocouple temperature measurement point 23. The thin film lead 3 is connected to the anode and the cathode, and uses the same material as the anode and the cathode. The thin film lead can be made at the same time as the thin film thermocouple, i.e., by using a mask printed with the shapes of the thermocouple anode / cathode and the same level lead, depositing the anode / cathode thin film material, and then depositing the other pole thin film material through a mask printed with the shape of the other pole.

[0073] The thin film thermal resistance 24 is made of a very thin metal film, and can be Pt100 or Pt1000. The thin film lead 3 can be gold, copper, silver or other conductive material, and is connected to both ends of the thin film thermal resistance 24 by four wires to form a four-wire thermal resistance testing mode, which can achieve high-precision testing.

[0074] Those skilled in the art understand that in a preferred embodiment, a groove can be pre-opened on the wafer at the positions of the thin film temperature sensor and the thin film lead, and the sensor and the lead are buried therein, and an optional cover sheet of the same material as the wafer can be placed on top. The thickness of the cover sheet is slightly thinner than the groove, and the wafer surface is almost the same after being fixed with high-temperature glue.

[0075] A groove can also be pre-opened on the wafer at the position of the connector, and the connector is buried therein. The lead can be led out from the side of the wafer.

[0076] The groove can be etched by dry or wet etching, laser grooving, or precision machining.

[0077] In another variant, the thin film temperature sensor and the thin film lead are directly glued or adhered to the surface of the wafer, which is within the protection scope of the present application. Preferably, in such a variant, the thin film temperature sensor and the thin film lead are attached to the surface of the wafer.

[0078] More specifically, in another preferred embodiment, the in-situ wafer thin film temperature sensor provided by the present application comprises a wafer, a thin film temperature sensor, a thin film lead, a connector, and a lead. The lead can include any one or more of a high-temperature lead, a vacuum through strap, a low-temperature lead, and an interface.

[0079] The wafer is a substrate for carrying the sensor, is the object to be measured, and is also a wafer for semiconductor processing and manufacturing. The material of the wafer can be a single crystal silicon wafer, a sapphire wafer, a quartz wafer, or a ceramic wafer. The size of the wafer can vary from 1 to 12 inches. The shape of the wafer can be circular or square.

[0080] The thin film temperature sensor is a device for measuring the temperature of the wafer, and can be a thermocouple (TC) or a thermal resistance (RTD). The RTD can be further divided into a negative temperature coefficient (NTC) thermistor and a positive temperature coefficient (PTC) platinum thermal resistance. The type of thermocouple can be selected from S, R, B, N, K, E, J, and T, and the preferred types are K, R, and B. The thermal resistance is preferably a platinum thermal resistance Pt100 or Pt1000. The thermocouple or thermal resistance can be deposited on the wafer using a vacuum coating method, such as physical vapor deposition (PVD) or chemical vapor deposition (CVD), to deposit the corresponding material, such as nickel-chromium and nickel-aluminum alloy for K-type thermocouples, and metal platinum for platinum thermal resistance.

[0081] The thin film lead is a metal lead deposited on wafer by vacuum deposition, which can be gold, copper, silver or other conductive materials or materials corresponding to thermocouple types, used for connecting temperature sensor and connector.

[0082] Optionally, an insulation layer such as SiO2 or SiN is deposited between wafer, temperature sensor and thin film lead for electrical insulation.

[0083] Optionally, a protective layer or insulation layer is deposited above temperature sensor and thin film lead for protection.

[0084] The connector is used for connecting thin film lead and wafer external lead, which can optionally contain thin lead and protective glue. The thin lead can be gold or aluminum wire, which can be connected to thin film lead and wafer external lead by ultrasonic bonder.

[0085] The high temperature lead is used for connecting thin film lead on wafer in high temperature environment, which can be high temperature resistant metal such as platinum rhodium, nickel chromium, nickel aluminum alloy, and the outer insulation layer can be ceramic or quartz sleeve or fiber tube.

[0086] The vacuum through belt is used for passing through O-shaped sealing ring on vacuum chamber with thickness <0.2mm, preferably 0.1mm. The selected material is polyimide (PI). The structure can be flexible printed circuit board or sandwich structure of PI tape-lead-PI tape. For non-vacuum requirements, equipment can work directly in atmospheric environment without vacuum through belt.

[0087] The low temperature lead is used in low temperature environment or outside vacuum chamber, which can be copper wire, enameled wire, cable and shielded wire.

[0088] The interface is used for connecting host computer and transmitting temperature signal, which can be DB, SCSI, 2pin interface, LEMO interface, etc.

[0089] In a preferred embodiment, the wafer can be pre-slotted at the position of thin film temperature sensor and thin film lead, and the sensor and lead can be buried therein, and the wafer can be optionally covered with a cover plate of the same material as the wafer. The cover plate is slightly thinner than the slot, and the wafer surface is almost the same after being fixed with high temperature glue.

[0090] In a preferred embodiment, the wafer can be pre-slotted at the position of connector, and the connector can be buried therein. The lead can be led out from the side of wafer.

[0091] The slot can be etched by dry or wet method, laser slotting or precision machining.

[0092] Referring to the above Figure 1A ,Figure 1B 、 Figure 2 、 Figure 3 、 Figure 4 In the embodiment shown in FIG. 1, the wafer 1 is the object to be measured. In a variant, the wafer 1 can be referred to as an object to be measured, and the thin-film temperature sensor provided by the present application is used to measure the object to be measured, and the thin-film temperature sensor and other components are arranged in the object to be measured by the method provided by the present application. In the above description of the embodiments of the present application, the object to be measured is replaced by the wafer 1 for the convenience of description, but all objects to be measured can be applied to the solution provided by the present application, which does not affect the protection scope of the present application.

[0093] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application.

Claims

1. An in-situ wafer thin film temperature sensor for measuring the temperature of a wafer (1), characterized in that, The thin-film temperature sensor (2), the thin-film lead wire (3), the connector (4) and the lead wire are connected in series, at least the thin-film temperature sensor (2) and the thin-film lead wire (3) are arranged in the groove on the wafer (1), an insulating layer is deposited between the wafer (1) and the thin-film temperature sensor (2) and the thin-film lead wire (3) for electrical insulation, and a protective layer is further deposited on at least the thin-film temperature sensor (2) and the thin-film lead wire (3); the lead wire comprises a high-temperature lead wire, a low-temperature lead wire and an interface, the low-temperature lead wire is located away from the wafer (1), one end of the interface is connected to the low-temperature lead wire, and the other end is used for connecting an external device to transmit temperature information; a part of the lead wire is arranged in the groove on the wafer (1), and the other end of the lead wire extends out of the wafer (1); the connector comprises a thin lead wire and a protective glue, and the thin lead wire is used for connecting at least the thin-film lead wire (3); The thin-film temperature sensor (2) is formed by physical vapor deposition or chemical vapor deposition on the wafer, and the thin-film lead wire (3) is a metal lead wire deposited on the wafer by vacuum plating; wherein the thin-film temperature sensor (2) and the thin-film lead wire (3) are directly pasted on the wafer by using a photolithography process or using a hollow mask for vacuum plating; At least a part of the groove is covered with a cover sheet made of the same material as the wafer (1); the thickness of the cover sheet is smaller than the depth of the groove, and the cover sheet is fixed with high-temperature glue to keep the surface of the wafer (1) flat.

2. The sensor of claim 1, wherein, The groove on the wafer (1) is generated by any of the following methods: - dry etching; - wet etching; - laser grooving; or - precision mechanical processing.

3. The sensor of claim 1, wherein, The thin-film temperature sensor (2) is a thermocouple or a thermal resistor.

4. The sensor according to claim 1, characterized in that The high-temperature lead wire is made of platinum rhodium, nickel chromium or nickel aluminum alloy.

5. The sensor of claim 4, wherein, An insulating layer composed of a ceramic or quartz sleeve or a fiber tube is arranged outside the high-temperature lead wire.

6. The sensor according to claim 4 or 5, characterized in that The low-temperature lead wire is a copper wire, an enameled wire, a cable or a shielded wire.

7. The sensor according to claim 1 or 4 or 5, characterized in that The lead wire further comprises a vacuum through belt located between the high-temperature lead wire and the low-temperature lead wire, and the high-temperature lead wire and the low-temperature lead wire are connected after penetrating into the vacuum through belt respectively.

8. The sensor of claim 7, wherein, The thickness of the vacuum through belt is not greater than 0.2 mm.

9. The sensor of claim 8, wherein, The vacuum through belt is composed of polyimide.

10. The sensor of claim 1, wherein, The material of the thin-film lead wire (3) is gold, copper or silver.

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