METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

• Main Authors: FUKUDA JOJI, ONODA TOSHIYASU, KASAI MASARU
• Format: Patent
• Language: English
• Published: 30.06.1998
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PROBLEM TO BE SOLVED: To avoid a reduction in throughput in manufacturing a semiconductor device by chemical dry etching, and also remove substantially all residues of a metal film while taking care of excessively digging the metal film of an electrode connection hole. SOLUTION: A tungsten film 14 in a region other than an electrode connection hole 11 is removed by chemical dry etching. This step for chemical dry etching comprises a first etching in which an etching speed is relatively high; and a second etching in which an etching speed after this first etching is relatively low. The first etching uses a first reactive gas of a mixture of a gas containing fluoric atoms, a gas containing chlorine atoms and an oxygen gas, and the second etching uses a second reactive gas of a mixture of a gas containing fluoric atoms and an oxygen gas and is carried out at lower power than the first dry etching. In this second reactive gas, a ratio of a gas containing fluoric atoms to an oxygen gas is 1:(1.5 to 1.0).