RU3838U1 - LIQUID ETCHING DEVICE - Google Patents

Abstract

A device for liquid etching, comprising a container for an etchant with an etch flow deflector and an etched object inside it, and a centrifugal pump including a cage with a rotor, characterized in that the cage with the pump rotor is placed inside the etchant, and the pump rotor is magnetically attached to the central part of the cover of the rotor cage as an etching object is placed on a support; the drive magnet is coaxially aligned with the pump outside the tank.

Description

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DEVICE FOR LIQUID TRAVINSH

The jelly model relates to the field of microelectronics, in particular, to single-chip production and laboratory practice. Chemical processing of KOivmoHeHTOB semiconductor devices.

It is known that the fabrication of matrix photosensitive

elements, nanpiiiviep, s CdHjj, .n &, requires a small etching of the defective layer with a thickness of the order of 10 und formed after mechanical processing of the crystal. In this case, it is necessary to maintain the plane of the photosensitive crystal with dimensions of the order of I cm within 1-2 for the subsequent successful connection of the photo signal with the IC, which is made, for example, using indium columns of small height. The isolation of indium columns from an indium layer several microns thick by photolithography also requires uniform etching of indium over the entire surface of the sample.

The semiconductor industry uses commercially available reactors with a minimum etchant dose of / v. I liter, they use expensive, poisonous, quick-degrading etchants, and the etching uniformity is low. In our case, the use of such reactors is not advisable. In laboratory practice, gravitational FIR reactors with a magnetic stirrer are usually used (see, for example, S.I. NishK Oorova-DeNisova Mechanical and. Chemical Processing. Moscow, Higher School, 1989). A reactor with a magnetic stirrer is a cylinder with a diaglite material at the bottom of which there is a ferro magnetic body in.}. ::. 1: 1 Czsche resistant shell. Under the bottom of the cylinder is a magnet that interacts with the mixer and drives it into rotation. There is a quasi-stationary distribution

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HOI 21/302 С2Ж 1/04 from the speeds of the reagent in the reactor, which experiences some disturbances when the sample is immersed in the reactor. The disadvantage of a reactor with a magnetic stirrer, as well as a gravitational one, is the lack of means of substantially varying the ratio of the etchant speeds within the specimen li associated with GTEH the possibility of selecting the mode of uniform etching. The closest technical solution to the claimed, / TOAejtfutT on the set of features accepted.1 for the prototype, is-. there is a device for hard pickling that implements the method according to patent SM 3732133 (. The device contains a container for liquid pickling and a pickling object placed on it on the support ring (according to the said patent - a mask of a color television picture tube mask). A deflector is mounted on the holder above the pick-up There is a discharge opening in the lower part of the tank, connected by a piping located outside the tank to a centrifugal pump, and the pump, in turn, is connected to a distribution ring pipe, which The girdle surrounds part of the tank. Inlet openings for liquid etching agent are located around the container. The device parts are made of gilded stainless steel. The device operates as follows: Etchant. From the bottom of the container through the outlet through the pipeline, the pump is pumped into the distribution line and through the inlet holes a capacitance, forming an oscillating flow, a deflector located along the flow path, forcing the distribution of the etchant velocities in, within the etching object, so that the floor to study the required dependence of the size of the hole on its location on the object.

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It is advisable to use such a device in continuous production with a large number of processes to be processed in oats with a large volume of the etchant used, which is due to the design of a centrifugal pump, in particular, a chemically resistant shaft seal of a mechanical drive.

The basis of the claimed useful modlie was completed. The task of protecting the lens is to poison the ale during batch etching ::; when the semiconductor devices

The problem is solved by the fact that, according to the model-model, and at the bottom of the fuselage for the etchant is placed around the rotor. centrifugal pump. The rotor of the centrifugal pump is given magnetic properties, for example, by strengthening the magnet on the lower surface of the rotor, or by making the rotor from a material with magnetic properties, or in another way. The magnet has a protective coating. The rotor cage is closed from above with a lid having holes in the center of the inlet and exhaust ports at the periphery. On the outside of the lid there are radial grooves converging to the insertion holes. On the central part of the cover, both the etched object is located on the support. With an emphasis on the peripheral part of the cover, an etchant flow deflector is installed. Outside the tank for the etchant, an external magnet for the rotation of the pump is installed coaxially with the centrifugal pump.

In FIG. I shows one embodiment of a liquid etching device.

At the bottom of the tank I for the etchant is placed around the 2 rotors 3 of the pump, equipped with a magnet 4 of the pump. The external magnet 5 of the pump rotation drive is located at the same level as the pump magnet 4. BOTH II rotors 3 of the pump are closed from above by a cover 6. W of the road with an inlet; w 7 for travitella in the central region and outlet 8 on the periphery. On the outside of the cover

the rotor cages are made radially grooves 9, converging to the openings of the hole 7. The etching object 10 is placed on the central axis of the casing 6 of the rotor cage 3, which is the support of the etching object IQ. A deflector II is installed on the peripheral part of the roof.

Parts of the device can be made of chemically resistant material, for example,. sTztoroplgsta, stozhku to a wide spetsstra grassyzzzzh.

Watroistzo works as follows. The external pump 5 of the pump rotation drive drives the rotor 3 of the centrifugal pump. The etchant, sucked in through the inlet openings 7 in the central part of the cover 6 of the cuff w 2 of the rotor 3, is ejected through the outlet openings 8 at the periphery. Then the etchant rises to the hole of the deflector II and is sent to the object

10 etching. The etcher flows around the etching object 10 and along the radial groove GL 9 in the cover 6 of the burner / rotor 2 of the rotor 3 enters the inlets 7. (The etchant current is shown by arrows). Since the etch flow rate in the radial grooves 9 of the arm 6 of the rotor cage is higher than the flow velocity above the surface of the etching object 10,

then, in accordance with Bernoulli's law, the etching object 10 is pressed against the cover 6 of the rotor cage. By changing the size, shape of the hole or holes of the deflector II, the distance between the deflector

11 and the etched object 10, by adjusting the rotational speed of the rotor 3 of the centrifugal pump, it is possible to obtain the desired distribution of etching rates in. the surface of the object 10 etching.

The volume of the etchant necessary for operation is connected with the characteristic size of the 10-etched object (sample A) by a ratio of 4.

-6scope through the hole of the deflector II. To do this, it is enough to eliminate ripples on the surface of the etchant, for example, using a transparent float or cover (not shown in the drawing).

Tarsh way, the proposed three liquid trawling in comparison with the device of the prototype has a smaller size and needs to work in a smaller amount of etchant.

Deputy CEO

V.P. Ponomarenko

Claims (1)

A device for liquid etching, comprising a container for an etchant with an etch flow deflector and an etched object inside it, and a centrifugal pump including a cage with a rotor, characterized in that the cage with the pump rotor is located inside the etchant, and the pump rotor is given magnetic properties, the central part of the cover of the rotor cage as an etching object is placed on a support; the drive magnet is coaxially aligned with the pump outside the tank.