Measuring method for maximum ion boundary angle in plasma etching simulation

Abstract

The invention discloses a measuring method for a maximum ion boundary angle in plasma etching simulation. A negative photoresist suspension structure is manufactured through once glue evening and twice exposure operations, the suspension structure is used as a mask for carrying out etching experiments, the real-time on-line precise measurement is carried out on various structure dimensions by the negative photoresist adhesion structures simultaneously manufactured on the same experiment sheet through the topographic analysis on the experiment results, and the maximum ion boundary angle under the certain etching experiment parameter setting is obtained for realizing the model parameter calibration in a plasma etching model. The method is simple and is easy to implement, the accuracy is high, in addition, the experiment flow process period is short, the cost is low, the universal applicability of the plasma etching model and the software of the plasma etching model is improved.

Description

technical field [0001] The invention belongs to the technical field of micro-electro-mechanical system (MEMS) process simulation technology, and specifically relates to deep reactive ion etching (DRIE) in the MEMS process and other plasma etching process model establishment and software implementation process, used for " The measurement method of the maximum ion boundary angle value determined by the value of "Model Parameter". Background technique [0002] With the continuous development of MEMS technology, the manufacture of devices with high aspect ratio movable structures has become one of the key technical points in the design of MEMS devices. Therefore, under the setting of certain etching experimental parameters (such as the coil power of the etching machine, the power of the plate, the gas flow rate, the chamber pressure, etc.), the accurate grasp of the etching morphology of the deep reactive ion etching that can be achieved has become A key link in the fabrication...

AI Technical Summary

Problems solved by technology

[0016] (1) The experimental steps and required equipment are relatively complicated. In addition to the most basic glue homogenizer and photolithography machine, related equipment for aluminum film sputtering is also required. The operation process is relatively complicated and takes a relatively long time

On the one hand, for the model builder, it is costly and time-consuming to perform multiple experiments to calibrate the relevant "model parameters"; on the other hand, for the user, the "model parameters" corresponding to the machine they use The calibration experiment is not convenient enough, which reduces the practicability of the model and related software

[0017] (2) In the actual etching process, due to the existence of the aluminum film layer, the heat dissipation effect is further deteriorated. When the glue is subjected to plasma etching bombardment, the tolerance time is very short, and it will become blurred or even Curl degumming phenomenon, poor masking performance, unable to achieve high-power deep etching experiments

[0018] (3) In the process of etching the exposed aluminum film layer, the exposed aluminum layer under the upper layer of photoresist is difficult to be completely etched away, so during the etching process, aluminum will be deposited on the surface of the substrate. In this case, a raised “hill” topography is formed on the substrate surface near the etched slot opening, such as Figure 4 As shown, it affects the accuracy of subsequent measurements

[0019] (4) Since the thickness of the upper photoresist and the overall thickness of the photoresist cannot be accurately measured, it is necessary to use white light interference to measure the topography of the cross-section before and after removing the glue

On the one hand, white light interference equipment is not easy to obtain, and the test cost is relatively expensive, which is not suitable for subsequent measurement applications in a large number of experiments; on the other hand, the measurement results of white light interference are not accurate enough. Based on certain assumptions, it ultimately affects the accuracy of the model

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