Chemical etching process and system

Abstract

A chemical etching process and apparatus includes a control unit, an etching unit, an etchant supply unit and an air supply unit. The control unit has a programmable electronic device through which various process parameters are input to control the operations of the etching unit, the etchant supply unit and the air supply unit. The etching unit has an etching table incorporated with the etchant supply unit and the air supply unit for providing a proper etching environment for a working object to be etched. The etchant supply unit is equipped with flow control valves and electromagnetic valves respectively for controlling the flow rate and the on / off operation of etchant supply through the control unit. Also, the air supply unit is equipped with flow control valves and electromagnetic valves respectively for controlling the flow rate and the on / off operation of air supply through the control unit.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method and apparatus for etching devices and cleaning thin disks, for example semiconductor wafers, glass substrates, photomasks and compact disks. More particularly, the present invention applies Bernoulli theorem to generate an instantaneous local vacuum effect on a surface of a working object by injecting an air stream, so as to easily remove residues residing in the trenches or on the surface of the working object. By suitably controlling an etchant spray and an air injection, an etching rate not only can be continuously kept steady, but also a maximum etching depth can be dramatically increased. Also, the present invention can be used for cleaning semiconductor devices with an extremely small gate width. BACKGROUND OF THE INVENTION [0002] In semiconductor fabrication processes, wet etching mainly uses chemical reactions between a thin film material and a specific solution to remove the thin film not covered by pho...

AI Technical Summary

Benefits of technology

[0005] An object of the present invention is to provide with a chemical etching process and apparatus, which applies Bernoulli theorem to generate an instantaneous local vacuum effect on a surface of a working object through injecting an air stream. Furthermore, the present invention provides with an etchant spray system and an etching table, which allows the working object to be moved in translation or rotation. Also, by suitably controlling the etching time, the concentration of etchant and the uniformity of etchant and quickly cleaning residues or etchant on the surface of the working object can achieve an optimum etching and cleaning result.

[0006] To achieve the above objects, a chemical etching process and apparatus according to the present invention comprises at least a control unit, an etching unit, an etchant supply unit and an air supply unit. Various process parameters can be input through a programmable electronic device of the control unit to control the operations of the etching unit, the etchant supply unit and the air supply unit. The etching unit has an etching table incorporated with the etchant supply unit and the air supply unit for providing a proper etching environment for the working object. Respective flow control valves and electromagnetic valves of the etchant unit and the air supply unit, which are controlled by the control unit, can be used to adjust the etchant flow rate and the airflow rate.

Problems solved by technology

However, in the etching process, the etchant is continuously consumed and thus lowers the concentration thereof and even forms a non-uniform concentration distribution of the etchant.

Although the non-uniform etchant will increasingly become uniform through diffusion mechanism or mass transfer by stirring, it is relatively slow to get a uniform etchant or hard to control the uniformity thereof.

This will result in an inaccurate control of the etching time.

Therefore, the negative pressure might be not enough to suck out the residues residing in the trenches or on the surface close to the center of rotation of the working object.

This method not only needs a driving power to rotate the etching table, but also the etching table is hard to be quickly accelerated and decelerated to a desired state due to the inertia effect.

And it is impossible to spray etchant onto the working object and suck out the residues simultaneously at a high-speed rotation.

Therefore, the method cannot effectively generate an enough negative pressure.

And the high-energy consumption will also increase the production cost.

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