Method for controlling thickness of photoresist film through dynamic temperature of photoetching hot plate

Abstract

The invention provides a method for controlling the thickness of a photoresist film through the dynamic temperature of a photoetching hot plate, and the method comprises the steps of heating the photoresist on a wafer through the hot plate with a concentric resistance wire, measuring the thickness of the photoresist film at each radius of the heated wafer, and obtaining a set of the radius of thewafer and the corresponding film thickness; obtaining a set of voltages corresponding to the resistance wires with different radiuses according to the relationship between the set and the voltage andtemperature of the hot plate; feeding back the measured film thickness to the hot plate by using a data feedback system; and using a hot plate voltage adjusting system to adjust the voltages corresponding to different radiuses of the hot plate according to the radiuses of the wafers fed back to the set of the hot plate, so that the thicknesses of photoresist films at different radiuses of the wafers tend to be uniform after the hot plate heats the photoresist on the subsequent wafers. According to the present invention, the independent temperature control over different areas of the hot plateis achieved by adjusting the voltages of the resistance wires with different radiuses of the hot plate, film thickness difference distribution generated by a spin-coating effect is compensated for, and therefore the non-uniformity of photoresist is improved, and the temperature is dynamically adjusted through the real-time feedback of film thickness data.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for controlling the thickness of a photoresist film by dynamic temperature of a photolithography hot plate. Background technique [0002] Such as figure 1 as shown, figure 1 It is shown as a schematic diagram of the distribution of resistive wires on a photoresist hot plate in the prior art. The existing hot plate heats the photoresist by heating the entire hot plate to a uniform temperature through the uniformly distributed resistance wires, thus making the photoresist There is a special thickness distribution in the film thickness, which affects the uniformity of the film thickness. Such as figure 2 as shown, figure 2 It is shown as a schematic diagram of the variation of photoresist film thickness with the radius of the hot plate in the prior art. Due to the characteristics of photolithography spin coating, uniform temperature will affect the film thickn...

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