US 5,147,493 AGranted

Plasma generating apparatus

AssigneesTokyo Electron Limited, Tokyo Electron Yamanashi Limited

InventorsEiichi Nishimura, Akihito Toda, Kazuhiko Sugiyama, Yukio Naitou

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Abstract

A plasma generating apparatus comprising a transformer including a primary winding connected to a high frequency power source and a secondary winding having two end terminals and a plurality of tap terminals connected between the end terminals, the transformer being adapted to deliver first and second high frequency electric powers with a phase difference of 180.degree. from the end terminals, upper and lower electrodes disposed in a vacuum chamber so as to be opposed at a distance from each other and supplied with the first and second high frequency powers, respectively, and a power ratio selector for switching the tap terminals to select the ratio between the first and second high frequency powers supplied to the electrodes, wherein a to-be-processed object placed on the lower electrode is processed by means of plasma formed between the electrodes.

Claims9

Dependent claims

A plasma apparatus comprising:

a transformer including a primary winding connected to a high frequency power source and a secondary winding electrically insulated from said primary winding and having two end terminals and a plurality of tap terminals connected between the end terminals, and intermediate tap means connected to a reference potential point, said transformer being adapted to deliver high frequency electric powers with a phase difference of 180.degree. from the end terminals;
a sealed chamber;
first electrode means disposed in said sealed chamber and having a plurality of fine pores through which reaction gas is fed into said sealed chamber;
second electrode means disposed in said sealed chamber and opposed to said first electrode means at a predetermined distance therefrom, a to-be-processed object being put on said second electrode means;
gas pipe means provided penetrating said second electrode means for introducing a gas medium for facilitating heat transfer between said second electrode means and said to-be-processed object;
means for connecting said first and second electrode means to said end terminals of said secondary winding, respectively;
power splitter means for adjusting the intermediate tap means of the secondary winding to supply to said second electrode means the high frequency power having a power level lower than that supplied to said first electrode means.

4 more elements

A plasma apparatus comprising:

a transformer including a primary winding connected to a high frequency power source and a secondary winding electrically insulated from said primary winding and having two end terminals and a plurality of tap terminals connected between the end terminals, said transformer being adapted to deliver first and second high frequency electric powers with a phase difference of 180.degree. as one of the tap terminals is grounded;
a sealed chamber;
an upper electrode disposed on the upper side within the sealed chamber, connected to one of the end terminals of the secondary winding, and supplied with the first high frequency electric power, said upper electrode connected to an external reaction gas source and having a plurality of fine pores through which reaction gas is fed into said sealed chamber from the external reaction gas source;
a lower electrode disposed on the lower side with reaction to said upper electrode and in the sealed chamber, carrying a to-be-processed object, connected to the other of the end terminals of the secondary winding, and supplied with the second high frequency electric power;
gas pipe means provided penetrating said lower electrode means for introducing a gas medium for facilitating heat transfer between said second electrode means and said to-be-processed object;
and
power splitter means for switching the tap terminals in order to supply to said lower electrode the first high frequency electric power having a level lower than that of the second high frequency electric power,
wherein the to-be-processed object is processed by means of plasma formed between the first and second electrodes.

5 more elements

Dependencies are inferred from the claim text.