JPH0274034A - Etching device for semiconductor wafer - Google Patents

Abstract

PURPOSE:To improve an exchange of a chemical and to contrive a reduction in a variability in a batch and a reduction in the variability of etching treatment within the surfaces of wafers by a method wherein an etching device is provided with a bottomed cylindrical chemical tank and a cylindrical wafer holder, by which the semiconductor wafers are held at constant pitches along the circumference of the holder turning the treating surfaces of the wafers, which are dipped in the chemical, toward the inside of the holder. CONSTITUTION:Semiconductor wafers 2 are respectively held by pins 3a and 3a of a non-bottomed cylindrical, wafer holder 3, the waters 2 are arranged along the circumference of the holder 3 turning inwards the treating surfaces of the wafers 2, the holder 3 is dipped in a chemical in a bottomed cylindrical etching tank 1 and with the chemical poured in the tank 1 through a bung hole 5 and a drainboard 4, an etching treatment is performed while the chemical is overflown the upper brim of the tank 1. Thereby, as the tank 1 is circular, a process between the inflow of the chemical and the overflow of the chemical is isotropic, the wafers 2, which are each set at distances equal from the inflow hole 5, are etched on the same conditions, a variability in a batch becomes small and at the same time, an exchange of the chemical is improved and the evenness of the etching treatment within the surfaces of the wafers is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for etching a semiconductor wafer.

[Conventional technology]

Conventionally, this type of etching apparatus has the following features, as shown in FIG.
The etching solution is injected into the tank from the bottom injection port 5 of the etching tank 1, and is formed into an upward flow as a laminar flow through the drainboard 4, overflowing from the upper edge of the etching tank 1, while the carrier 7 An etching process was being performed on wafer 2.

Incidentally, the conventional etching bath 1 has a rectangular box shape, and the wafers 2 are housed in a carrier 7 vertically in parallel in a horizontal row.

[Problem to be solved by the invention]

As mentioned above, the conventional etching apparatus is a rectangular parallelepiped with a rectangular bottom of the tank 1, and there is an inlet 5 for the circulating and filtered chemical solution in the center of the bottom.
A grating 4 with holes drilled under appropriate conditions is installed, but in reality the filtered chemical solution spreads unevenly, so
This results in poor uniformity within the batch. Another disadvantage is that the semiconductor wafers 2 are set in a row on the carrier 7, and the liquid exchange between the two wafers 2 is not sufficient, resulting in a large difference in the etching rate between the top and bottom of the semiconductor wafers 2. was there.

An object of the present invention is to provide a semiconductor wafer etching apparatus that solves the above problems.

[Differences between the invention and the prior art]

The present invention differs from the conventional semiconductor wafer etching apparatus described above in that semiconductor wafers are lined up one by one at positions equidistant from the inlet of the chemical solution and etched.

[Means to solve the problem]

In order to achieve the above object, the present invention provides an etching apparatus for etching semiconductor wafers, which includes a round-shaped chemical liquid slider with a bottom, and a semiconductor wafer to be immersed in the chemical liquid in the chemical tank, with the processing surface facing inward. It has a cylindrical wafer stand that holds the semiconductor wafers at a constant pitch in the circumferential direction.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIGS. 1(a) and 1(b) are diagrams showing an embodiment in which the present invention is applied to an etching solution overflow type etching apparatus.

In the figure, the etching tank 1 is shaped like an oval cylinder with a bottom.
A chemical injection port 5 is opened in the center of the circular bottom of the etching tank 4fJ1, and the etching tank 1 is located at a higher position than the injection port 5.
A drainboard 4 for controlling the flow of the chemical solution from the injection port 5 to an N flow is installed inside.

On the other hand, the wafer stand 3 is configured in a bottomless cylindrical shape, and two bins 3a, 3a for holding the lower edge of the wafer 2 are arranged on the inner peripheral surface of the cylindrical wafer stand 3 at a constant pitch along the circumferential direction. Plant every time.

In the embodiment, the bins 3a, 3 of the cylindrical wafer stand 3
A holds the wafers 2, and arranges the wafers 2 in the circumferential direction with the processing surfaces facing inward.The wafer stand 3 is immersed in the chemical solution in the etching tank 1, and the X solution is injected into the injection port 5 and The etching process is carried out by pouring into the tank 1 through the drainboard 4 and overflowing from the upper edge of the tank 1.

According to the present invention, since the etching tank 1 is circular, the process from the inflow of the leaf fluid until its overflow is uniform, and the semiconductor wafers 2, each set at an equal distance from the inlet 5, are placed under the same conditions. The etching process reduces variations within batches, improves liquid exchange, and improves in-plane uniformity.

(Example 2) FIG. 2 is a diagram showing a second embodiment of the present invention.

In this embodiment, a magnetic stirrer 6 for stirring is installed at the center of the bottom of a cylindrical etching tank l.
The chemical solution in the tank is stirred and the flow is controlled to a laminar flow using the grates 4. - The left semiconductor wafer 2 is set on the inner peripheral surface of the wafer stand 3 with the processing side facing inward, and the etching tank 1 is set. Etching is performed by immersing the material in a chemical solution.

〔Effect of the invention〕

As explained above, the present invention allows etching to be performed on each wafer within a batch under the same conditions and with good liquid exchange, reducing variations within a batch and within the wafer surface. It has the effect that it can.

[Brief explanation of the drawing]

FIG. 1(a) is a diagram showing implementation S1 of the present invention, FIG. 1(b)
) is a sectional view showing a wafer stand, FIG. 2 is a view showing a second embodiment of the present invention, and FIG. 3 is a view showing a conventional semiconductor wafer etching apparatus. 1... Etching bath 2... Semiconductor wafer 3
- Wafer stand 4... Slatted grout 5... Inlet 6... Magnet star rough... Carrier Figure 2 Figure 3 Coffin 3

Claims (1)

[Claims] (1) In an etching apparatus that performs etching processing on semiconductor wafers, there is a cylindrical chemical bath with a bottom, and the semiconductor wafer is immersed in the chemical bath in the chemical bath, and the semiconductor wafer is placed in the circumferential direction with the processing surface facing inward. 1. A semiconductor wafer etching apparatus comprising: a cylindrical wafer stand that holds the wafer at a constant pitch along the wafer.