JPS6165437A - Dry etching method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a dry etching method used in the manufacture of semiconductor devices such as injection collector circuits.

Conventionally, in reactive ion etching in which a substrate to be etched (an optical mask or a wafer) is placed between two 76-tMOs, the periphery of the substrate to be etched is etched more than the center. Etching progressed quickly, and by the time etching in the center was completed, there was a tendency for the peripheral areas to become considerably over-etched. This phenomenon is caused by the fact that the viscous ions in the plasma that contribute to the actual etching are consumed one after another by etching in the central part of the semiconductor substrate, whereas in the peripheral part they do not contribute at all to etching outside the substrate to be etched. This is due to the fact that activated ions that have not been activated are sequentially supplied and the etching progresses. Due to this phenomenon, on the board after etching,
There is a large difference in the dimensions of the device between the center and the periphery, leading to a decrease in manufacturing yield.

Problems to be Solved by the Invention As mentioned above, the problem that needs to be solved is that the difference in etching speed between the periphery and the center of the substrate to be etched causes a low manufacturing yield. be.

Technical Means for Solving Problem 29 To address the above-mentioned problems, in the present invention, the holder for setting the substrate to be etched in the etching chamber is made of the same material as the substrate to be etched.

E1 Effect In the present invention, since the holder surrounding the edge of the substrate to be etched is made of the same material as the substrate to be etched, activated ions in the etching chamber involved in etching are protected against the peripheral and central portions of the substrate to be etched. The condition no longer holds, and the difference in etching speed between the peripheral and central areas disappears.

To, Example Next, the present invention will be explained with reference to examples.

FIG. 1 is a sectional view showing an etching apparatus according to an embodiment of the present invention and a substrate to be etched (an optical mask in this example) set therein, and FIG. 2 is a plan view of the holder for the substrate to be etched shown in FIG. It is. 1 and 2, an upper electrode 2 and a lower electrode 3 are provided facing each other in an etching chamber 1, and a chromium thin film of about 100 OA is placed on a glass substrate between these opposing electrodes as a substrate to be etched. An optical mask 6 on which etching is deposited is set on each support portion of the substrate holder 4 to be etched, which is supported by the holder support column 5.

Here, the substrate holder 4 is made of the same chromium as the part to be etched of the optical mask 6, and as shown in FIG. The set substrate to be etched is supported by the protrusions at the four corners of this hole. In this state, etching gas is introduced from the etching gas introduction lower, and while the gas is exhausted from the exhaust port 8, a high-volume voltage is applied from the high-frequency power source 9 between the electrodes 2 and 3 to etch the optical mask 6. conduct. In this case, the optical mask 6
Since the holder 4 and the holder 4 are made of the same chrome, the same amount of etching is performed. However, since the dragon is a very small amount of etching, 100 OX per etching cycle, if the thickness of the holder 4 is 31 mm or more, one holder can perform 10,000 etchings, so there is no need to worry about the consumption of the holder. Ranarai.

Note that the holder 4 does not necessarily have to be made of the same material as the material to be etched, and the material to be etched can be simply vapor-deposited on the surface of the holder.

Effects of the Invention As mentioned above, in the conventional method, the energy of active ions existing in the holder part is not consumed in the holder part, but flows into the substrate to be etched one after another, etching the peripheral part of the substrate particularly strongly. In contrast to the difference in the etching state between the central and peripheral areas, in the method of the present invention, the activated ions in the plasma are consumed equally in both the substrate to be etched and the holder. Uniform etching is performed over the entire surface of the substrate, eliminating the reduction in yield due to etching differences.

[Brief explanation of drawings]

! 1 is a sectional view showing a substrate to be etched set in a dry etching apparatus according to an embodiment of the present invention, and FIG. 2 is a plan view of the holder for the substrate to be etched shown in FIG. DESCRIPTION OF SYMBOLS 1...Etching chamber, 2...Upper electrode, 3...Lower tD, 4...Etched substrate holder, 5...Holder Support pillar, 6...
...Optical mask, 7... Etching gas inlet, 8... Etching gas outlet, 9...
...High frequency power supply. Agent: Susumu Uchihara, patent attorney

Claims (1)

[Claims] In dry etching performed by placing a substrate to be etched between two opposing electrodes, at least a surface material of a holder for setting the substrate to be etched is the same material as the substrate to be etched. Dry etching method.