Title:
DRY ETCHING FOR TUNGSTEN METAL
Document Type and Number:
Japanese Patent JPS6130037
Kind Code:
A
Abstract:
PURPOSE:To realize formation of ultraminiature pattern of tungsten using a photo resist mask by increasing an etching speed ratio between tungsten W and photo resist utilizing a mixed gas of CF4 and N2. CONSTITUTION:The CF4 and N2 are supplied to a vacuumreaction chamber 1 and it is kept at 10<-3>-10Torr, discharge is generated by applying a high frequency to an electrode 2 in order to isolate the gas and activate it. A tungsten substrate 4 provided with photo resist mask is etched and volatile biproduct WF6 by reaction is released to the outside. In this case, when a mixing rate of N2 is in the range of 0.05-70vol%, etching rate of W is higher than that of photo resist. Since etching rate changes in accordance with the conditions of gas pressure, gas flow rat and high frequency power, etc., these must be kept to constant respectively. In this event, a W film as thick as about 0.5mum is patterned through the dry etching with so-called a large selection ratio and thereby a high performance semiconductor element can be formed.
Inventors:
ADACHI SADAO
SUSA NOBUHIKO
SUSA NOBUHIKO
Application Number:
JP14968484A
Publication Date:
February 12, 1986
Filing Date:
July 20, 1984
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
International Classes:
C23F4/00; H01L21/302; H01L21/3065; (IPC1-7): C23F1/00
Attorney, Agent or Firm:
Takashi Sawai