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CN-115684249-B - Photoetching machine and method for measuring evaporation power of liquid film on substrate surface of photoetching machine

CN115684249BCN 115684249 BCN115684249 BCN 115684249BCN-115684249-B

Abstract

The invention provides a photoetching machine, which comprises an irradiation system, a mask, a projection system, a substrate and a substrate surface liquid film evaporation power measuring device, wherein the substrate surface liquid film evaporation power measuring device comprises a substrate bearing unit, a fluid transmission unit, a fluid flow control unit, a fluid temperature control unit and a fluid temperature measuring unit, the substrate bearing unit is used for bearing a substrate, the substrate bearing unit is of a hollow structure, the fluid transmission unit is used for introducing a fluid medium into the substrate bearing unit, the fluid medium is gas, the fluid flow control unit is used for controlling and measuring the flow of the fluid medium flowing into the substrate bearing unit, and the fluid temperature measuring unit is used for measuring the temperature difference of the fluid medium flowing into and flowing out of the substrate bearing unit. By adopting gas as the fluid medium, the requirements on flow control precision and temperature measurement precision can be obviously reduced.

Inventors

  • DAI SIYU

Assignees

  • 上海微电子装备（集团）股份有限公司

Dates

Publication Date
20260508
Application Date
20210730

Claims (11)

  1. 1. The photoetching machine is characterized by comprising an irradiation system, a mask, a projection system, a substrate and a substrate surface liquid film evaporation power measuring device, wherein the irradiation system projects a pattern on the mask onto the substrate through the projection system, the substrate surface liquid film evaporation power measuring device comprises a substrate bearing unit, a fluid transmission unit, a fluid flow rate control unit, a fluid temperature control unit and a fluid temperature measuring unit, the substrate bearing unit is used for bearing a substrate, the substrate bearing unit is of a hollow structure, the fluid transmission unit is used for introducing a fluid medium into the substrate bearing unit, the fluid medium is gas, the fluid flow rate control unit is used for controlling and measuring the flow rate of the fluid medium flowing into the substrate bearing unit, the fluid temperature control unit is used for controlling the temperature of the fluid medium flowing into the substrate bearing unit, the fluid temperature measuring unit is used for measuring the temperature difference of the fluid medium flowing into and flowing out of the substrate bearing unit, and the material thermal conductivity of the substrate bearing unit is more than or equal to 100W/(m DEG C).
  2. 2. The lithographic apparatus of claim 1, further comprising a fluid input unit and a fluid output unit, the substrate carrying unit comprising a fluid inlet and a fluid outlet, the fluid transfer unit being in communication with the fluid inlet through the fluid input unit, the fluid output unit being in communication with the fluid outlet.
  3. 3. The lithographic apparatus of claim 2, wherein the fluid temperature measuring unit comprises a first temperature sensor arranged at the fluid input unit for measuring the temperature of the fluid medium flowing into the substrate carrying unit and a second temperature sensor arranged at the fluid output unit for measuring the temperature of the fluid medium flowing out of the substrate carrying unit.
  4. 4. The lithographic apparatus of claim 1, wherein the substrate carrying unit is internally provided with at least one rib.
  5. 5. The lithographic apparatus of claim 4, wherein a plurality of ribs are provided within the substrate carrying unit, the plurality of ribs being arranged in a staggered array.
  6. 6. The lithographic apparatus of claim 4, wherein the rib has a linear or curved shape.
  7. 7. The lithographic apparatus of claim 6, wherein the rib has a J-shape.
  8. 8. The lithographic apparatus of claim 1, wherein the fluid medium is air or an inert gas.
  9. 9. The lithographic apparatus of claim 1, wherein the fluid temperature control unit is a heat exchanger.
  10. 10. The lithographic apparatus of claim 1, wherein the flow control unit is a volumetric flow control unit or a mass flow control unit.
  11. 11. A method for measuring the evaporation power of a liquid film on a substrate surface of a lithography machine, characterized in that the evaporation power of the liquid film on the substrate surface of the lithography machine is measured by using the apparatus for measuring the evaporation power of a liquid film on a substrate according to any one of claims 1 to 10, the substrate is placed on a substrate carrying unit, a fluid medium introduced into the substrate carrying unit is a gas, and the method for measuring the evaporation power of the liquid film on the substrate surface of the lithography machine comprises: Measuring the flow rate of the fluid medium flowing into the substrate carrying unit and the temperature difference between the fluid medium flowing into and out of the substrate carrying unit, and And obtaining the evaporation power of the liquid film on the surface of the substrate according to the flow rate of the fluid medium flowing into the substrate bearing unit and the temperature difference between the fluid medium flowing into and out of the substrate bearing unit.

Description

Photoetching machine and method for measuring evaporation power of liquid film on substrate surface of photoetching machine Technical Field The invention relates to the technical field of photoetching machines, in particular to a photoetching machine and a method for measuring the evaporation power of a liquid film on the surface of a substrate of the photoetching machine. Background FIG. 1 is a schematic diagram of an immersion lithography machine. The illumination system 101 forms a beam of light that projects a pattern on the mask 102 through the projection system 104 onto the substrate 108. The mask 102 is supported by a mask stage 103. The substrate 108 is supported by a motion stage 107, and the motion stage 107 is movable in a horizontal direction at a high speed. Projection system 104 is supported by frame 105. An immersion liquid maintenance system 106 is provided between the projection system 104 and the motion stage 107 to maintain the propagation medium of the beam of light in this region as water. When the motion stage 107 moves at a high speed, the immersion liquid maintaining system 106 is divided into two parts, and the immersion liquid maintaining system 106 ensures that the liquid does not flow out from the gap between the two parts, but cannot avoid dragging out a residual liquid film of hundreds of nanometers. The liquid film evaporates in the air to cool, so that the temperature of the substrate is reduced, and deformation is generated. The refrigerating power generated by evaporating the residual liquid film on the surface of the substrate is small (usually less than 5W), but the projection accuracy of the pattern is affected by small deformation. Therefore, the evaporation power needs to be measured to formulate a corresponding temperature compensation strategy. The evaporation power itself cannot be measured directly, but the temperature measurement can be converted into the magnitude of the evaporation power. The liquid film is generated when the motion platform moves at a high speed, and the coverage area and the shape of the liquid film can change along with the motion state at any time. Fig. 2 shows a typical device for measuring evaporation power, which comprises a substrate carrying unit 111 for carrying a substrate 108, wherein a water inlet pipe 109 is arranged in the substrate carrying unit 111, a first temperature sensor 110a is arranged at the inlet of the water inlet pipe 109 for measuring the water temperature at the inlet, and a second temperature sensor 110b is arranged at the outlet of the water inlet pipe 109 for measuring the water temperature at the outlet. The substrate carrying unit 111 is, for example, in a disc shape, and the structure of the substrate carrying unit 111 is not limited to a disc, and may be square or any other shape, and may cover the entire substrate. By measuring the temperature difference between the inlet and the outlet, the evaporation power can be calculated: wherein dQ/dt is the endothermic power of water, the unit is W, C is the specific heat capacity of water, 4.18 kJ/(kg. DEG C), ρ is the density of water, dV/dt is the flow of water, and DeltaT is the temperature difference measured at the inlet and outlet. When the evaporation power is fixed, the flow rate of water is inversely proportional to the temperature difference measured by the sensor. The larger the flow of water, the smaller the temperature difference between the inlet and the outlet, the higher the measurement precision of the sensor is required, the lower the precision of the sensor is selected, the smaller the flow is required, and the higher the precision requirement of flow control is. Assuming that the evaporation power is-5W, (dV/dt). DELTA.T= -0.072 DEG C.L/min is obtained, wherein dV/dt is the flow rate of water and DELTA.T is the temperature difference measured at the inlet and outlet. And further supposing that the flow is controlled at 0.7L/min, the inlet-outlet temperature difference is about-0.1 ℃. The measurement accuracy, even if calculated as poor 5%, puts high demands on flow control and temperature measurement accuracy. If the actually required measured evaporation power is smaller, the precision requirement can be further improved. Disclosure of Invention The invention aims to provide a photoetching machine and a method for measuring the evaporation power of a substrate surface liquid film of the photoetching machine, so as to solve the problems of flow control and overhigh temperature measurement precision required in the process of measuring the evaporation power. In order to solve the technical problems, the invention provides a photoetching machine, which comprises an irradiation system, a mask, a projection system, a substrate and a substrate surface liquid film evaporation power measuring device, wherein the irradiation system projects a pattern on the mask onto the substrate through the projection system, the substrate surface liquid film evaporati