JPS62264626A - Wet etching apparatus - Google Patents

Abstract

PURPOSE:To remove selectively the metal film on a semiconductor substrate surface only and avoid defects produced when a protective film is formed and simplify a process by providing a nozzle which spout out and supply etchant to the circumference of the back surface of the substrate. CONSTITUTION:An attracting table 4 which attracts a semiconductor substrate 8 by vacuum is provided in the treatment chamber 7 of a wet-etching apparatus and the table 4 is turned by a table turning motor 5. An etchant spouting nozzle 2 is provided directly above the table 4 and another etchant spouting nozzle 1 is provided toward the circumference of the back surface of the substrate 8 supported by the table 4 and further a gas spouting nozzle 3 is provided toward the circumference of the front surface of the substrate 8. A metal film 9 only on the circumference of the backsurface of the turning substrate 8 is removed by the etchant spouted out of the nozzle 1 and the gas flow spouted out of the nozzle 3 prevents the etchant from creeping onto the front surface of the substrate 8 so that only the metal film 9 on the front surface of the substrate 8 can be selectively removed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wet etching apparatus used for manufacturing semiconductor devices.

[Conventional technology]

Conventionally, when removing a metal film grown on the surface of a semiconductor substrate that is unnecessary for circuit formation (for example, around the wafer), only the peripheral part is exposed to light or treated with a solvent when forming a protective film before etching. The protective film was removed only from the periphery of the wafer to expose the metal film, and the exposed metal film was removed during etching.

[Problem that the invention seeks to solve]

However, in the conventional metal film removal method described above, abnormalities in the thickness of the protective film in the peripheral area of the semiconductor substrate may cause partial remaining of the protective film, or the solvent may be removed from the substrate during the solvent treatment of the peripheral area. Intrusion toward the center causes defects such as deterioration of pattern processing, which is one of the causes of a decrease in yield.

An object of the present invention is to provide an apparatus that removes a metal film formed on the periphery of a semiconductor substrate without going through a protective film process.

[Means for solving problems]

The present invention is a single-wafer type wet etching apparatus in which a semiconductor substrate is held on a table, the semiconductor substrate is rotated by the table, and a chemical solution is dropped onto the surface of the substrate to etch a metal film on the surface. This wet etching apparatus is characterized by being equipped with a nozzle that sprays etching liquid toward the periphery of the back surface of the substrate.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, in the apparatus of the present invention, a suction table 4 for vacuum suctioning a semiconductor substrate 8 is rotatably installed in a processing chamber 7, and an etching liquid injection nozzle 1 is disposed directly above the table 4. An etching liquid jetting nozzle 1 is disposed toward the periphery of the back surface of the semiconductor substrate 8 held on the table 4, and a gas jetting nozzle 3 is further disposed toward the periphery of the front surface of the semiconductor substrate 8 on the table 4. It is. 5 is a motor that rotates the suction table, and 6 is a drain/exhaust port provided at the bottom of the processing chamber 7.

In the embodiment, the semiconductor substrate 8 is rotated together with the table 4, and the metal film 9 on the periphery of the substrate 8 is removed by injecting etching liquid from the nozzle 1 toward the back surface of the substrate only on the periphery thereof. The etching liquid tries to go around from the back side of the substrate 8 to the front surface, but because the gas flow from the nozzle 3 prevents the etching liquid from going around the substrate surface, only the peripheral part of the metal film 9 is removed. Ru.

The removal amount of the metal film 9 is determined by the chemical injection pressure of the lower nozzle 1,
It is determined by the rotation speed of the table 4, and can be freely set by changing the strength of each parameter.

〔Effect of the invention〕

As explained above, the present invention provides a nozzle that sprays and supplies an etching solution to the periphery of the back surface of a semiconductor substrate.
It is possible to selectively remove only the metal film on the periphery of the metal film on the substrate surface, eliminating the need for conventional processes such as forming a protective film and removing the peripheral protective film, and processing can be performed immediately after the metal film grows. This has the effect of eliminating the causes of defects during the formation of the protective film and simplifying the number of steps itself.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a partially enlarged view. 1.2...Etching liquid injection nozzle, 3...Gas injection nozzle, 4...Adsorption table, 5...Table rotation motor, 6...Drainage/exhaust port, 7...Processing Chamber, 8...Semiconductor substrate, 9...Metal film patent applicant Kyushu NEC Corporation, /゛

Claims (1)

[Claims] (1) In a single-wafer type wet etching apparatus in which a semiconductor substrate is held on a table, the semiconductor substrate is rotated by the table, and a chemical solution is dropped onto the surface of the substrate to etch the metal film on the surface. A wet etching device characterized by being equipped with a nozzle that sprays an etching solution toward the periphery of the back surface of a substrate.