Active solid-state devices (e.g. – transistors – solid-state diode – Field effect device – Having insulated electrode
Patent
1996-05-15
1997-05-27
Whitehead, Jr., Carl W.
Active solid-state devices (e.g., transistors, solid-state diode
Field effect device
Having insulated electrode
257382, 257384, 257388, 257412, 257764, 257768, H01L 2976, H01L 2994, H01L 31062, H01L 31113
Patent
active
056335229
ABSTRACT:
The present invention is directed to a unique silicon based MOS transistor having an inverse-T refractory metal gate structure. The gate fabricated according to this invention comprises a main CVD tungsten portion and a lower sputtered tungsten portion outwardly extending from the bottom of the CVD portion such that a cross section of the gate appears as an inverted "T". A Cl.sub.2 /O.sub.2 plasma etch is used to etch the CVD tungsten layer and a chemical etch is used to etch the sputtered tungsten layer to form the gate electrode. It has been discovered that sputtered tungsten is more resistant to Cl.sub.2 /O.sub.2 reactive ion etch than is CVD tungsten. The sputtered tungsten layer acts as a shield to protect the underlying gate oxide layer from ion damage throughout the fabrication process.
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Dorleans Fernand
Hsia Liang-Choo
Hsu Louis L. C.
Larsen Gerald R.
Schwartz Geraldine C.
International Business Machines - Corporation
Mortinger Alison
Whitehead Jr. Carl W.
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