Method for forming a multi-layer deposited film

Claim 1

A method for forming a multi-layer deposited film on a substrate in a film forming space, comprising: separately introducing into the film forming space (i) an active species (A) at a first flow rate (a) said active species (A) formed by decomposition of a starting material gas (A) which is a major flow rate component, said starting material gas (A) being a compound containing silicon and halogen, (ii) an active species (B) at a second flow rate (b), said active species (B) formed by decomposition of a starting material gas (B) which is a minor flow rate component, said starting material gas (B) being a compound containing germanium or carbon and halogen, and (iii) an active species (C) at a third flow rate (c), said active species (C) being reactive with said active species (A) and said active species (B) and formed from a compound (C), compound (C) being a hydrogenated silicon compound; forming a first deposited film layer on the substrate by permitting said active species (A) and active species (B) to form a mixture, and allowing said mixture to chemically react with said active species (C) to thereby produce the first deposited film layer on the substrate having a first composition; and forming at least a second deposited film layer on top of said first deposited film layer by varying said second flow rate (b) relative to said first flow rate (a) to thereby produce said at least second deposited film layer having a second composition different from said first composition; wherein the said first flow rate (a), said second flow rate (b) and said third flow rate (c) are maintained such that ((a)+(b)/(c)) is within a range of between 10/1 and 1/10 and wherein said first deposited film layer and said at least second deposited film layer each have a thickness of between 10 Å and 200 Å.

Claim 2

A method for forming a multi-layer deposited film on a substrate in a film forming space, comprising: separately introducing into the film forming space (i) an active species (A) at a first flow rate (a) said active species (A) formed by decomposition of a starting material gas (A) which is a major flow rate component, said starting material gas (A) being a compound containing silicon and halogen, (ii) an active species (B) at a second flow rate (b), said active species (B) formed by decomposition of a starting material gas (B) which is a minor flow rate component, said starting material gas (B) being a compound containing germanium or carbon and halogen, and (iii) an active species (C) at a third flow rate (c), said active species (C) being reactive with said active species (A) and said active species (B) and formed from a compound (C), compound (C) being a hydrogenated silicon compound; forming a first deposited film layer on the substrate by permitting said active species (A) and active species (B) to form a mixture, and allowing said mixture to chemically react with said active species (C) to thereby produce the first deposited film layer on the substrate having a first composition; and forming at least a second deposited film layer on top of said first deposited film layer by varying said second flow rate (b) relative to said first flow rate (a) to thereby produce said at least second deposited film layer having a second composition different from said first composition; wherein the said first flow rate (a), said second flow rate (b) and said third flow rate (c) are maintained such that ((a)+(b)/(c)) is within a range of between 10/1 and 1/10 and wherein said first deposited film layer and said at least second deposited film layer each have a thickness of between 10 Å and 200 Å.