Method for solving problem of abnormal photoresist coating under condition of high-step substrate

Abstract

The invention relates to the field of a process for manufacturing an integrated circuit and discloses a method for solving the problem of abnormal photoresist coating under the condition of a high-step substrate. The method comprises the following steps of: (1) firstly coating a layer of developable anti-reflecting material on the high-step substrate to reduce the up-and-down height of a positionof a step needing coating the photoresist on the surface; and (2) coating the photoresist on the developable anti-reflecting material. A layer of relatively thin developable anti-reflecting material is coated firstly on the high-step substrate, and the developable anti-reflecting material has relatively good flatness and reduces the height of the step on the surface, so the abnormal coating and appearance defect caused by the high step are eliminated.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing technology, in particular to a method for solving abnormal photoresist coating. Background technique [0002] With the continuous development of integrated circuits, the minimum line width of transistors continues to shrink. The continuous reduction of line width firstly requires that the lines defined by the photolithography process become narrower and narrower, and of course the requirements for the etching process are also higher and higher. In order to meet the requirements of lithography, in addition to the continuous upgrading of lithography equipment, people also use other technologies to improve the quality and accuracy of lithography. [0003] like figure 1 , figure 2 As shown, in some special processes, some layers will produce high steps after etching. Taking the top metal (top metal) as an example, the thickness of aluminum reaches more than several microns (even up ...

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Problems solved by technology

[0003] like figure 1 , figure 2 As shown, in some special processes, some layers will produce high steps after etching. Taking the top metal (top metal) as an example, the thickness of aluminum reaches more than several microns (even up to 4um), and the substrate surface after metal etching The step undulation is severe, which will cause photoresist coating uniformity and abnormal appearance in the subsequent photolithography process. There are two points that are especially worthy of attention: 1. The thickness of photoresist on dense metal lines and isolated metal lines is significantly different. difference, thus causing etch non-uniformity, see figure 1 ; 2. In the deep groove of the sparse pattern, the gas is not discharged in time when the photoresist is coated, and bubbles are generated, see figure 2

The usual way to solve the above problems is to thicken the thickness of the photoresist, but the required thickness is usually 1um higher than the step depth to solve the above problems, and the required film thickness coating main speed will be lower than the hardware can guarantee Minimum speed, glue thickness uniformity cannot be guaranteed.

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