Apparatus and method for forming low dielectric constant film
AssigneeASM Japan K.K.
InventorsNobuo Matsuki, Seijiro Umemoto, Yasuyoshi Hyodo
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Abstract
A CVD apparatus includes (i) a reaction chamber; (ii) a reaction gas inlet; (iii) a lower stage on which a semiconductor substrate is placed; (iv) an upper electrode for plasma excitation; (v) an intermediate electrode with plural pores through which the reaction gas passes, wherein a reaction space is formed between the upper electrode and the intermediate electrode; and (vi) a cooling plate disposed between the intermediate electrode and the lower stage, wherein a transition space is formed between the intermediate electrode and the cooling plate, and a plasma-free space is formed between the cooling plate and the lower stage.
Claims29
A CVD apparatus for forming a thin film on a semiconductor substrate by plasma reaction, comprising:
- a reaction chamber;
- a reaction gas inlet for introducing a reaction gas into the reaction chamber;
- a lower stage on which a semiconductor substrate is placed in the reaction chamber, said lower stage functioning as a lower electrode;
- an upper electrode for plasma excitation in the reaction chamber;
- an intermediate electrode with plural pores through which the reaction gas passes, said intermediate electrode being disposed below the upper electrode, wherein a reaction space is formed between the upper electrode and the intermediate electrode;
- and
- a cooling plate with plural pores through which the reaction gas passes, said cooling plate being disposed between the intermediate electrode and the lower stage, said cooling plate being controlled at a temperature lower than the intermediate electrode, wherein a transition space is formed between the intermediate electrode and the cooling plate, and a plasma-free space is formed between the cooling plate and the lower stage.
13 The apparatus according to claim 12, wherein the cooling gas is a non-reactivity gas.
15 The apparatus according to claim 1, wherein the lower stage is controlled at a temperature of 100° C. or lower.
A method for forming a thin film on a semiconductor substrate by plasma reaction, comprising the steps of:
- introducing a reaction gas into an upper section of a reaction chamber;
- exciting a plasma in the upper section to react the reaction gas by applying electrical power between an upper electrode and a lower stage on which a substrate is place;
- enclosing the plasma in the upper section by providing below the upper electrode an intermediate electrode having the same electrical potential as the lower stage, said intermediate electrode having plural pores through which the activated reaction gas passes;
- cooling a section under the upper section by controlling a cooling plate disposed between the intermediate electrode and the lower stage at a temperature lower than the intermediate electrode, said cooling plate having plural pores through which the cooled reaction gas passes, wherein a middle section is formed between the intermediate electrode and the cooling plate;
- and
- controlling the lower stage at a temperature lower than the cooling plate, wherein a lower section is formed between the cooling plate and the lower stage, whereby reaction products accumulate on the substrate.
23 The method according to claim 22, wherein the cooling gas is a non-reactivity gas.
Dependencies are inferred from the claim text.