Etch process for dielectric materials comprising oxidized organo silane materials

A method of anisotropically plasma etching an etch pattern through a layer of C-doped silicon oxide of a first structure that is fabricated by depositing the C-doped silicon oxide layer on a layer of silicon oxide, the method comprising:

• a) depositing a photoresist layer on the C-doped silicon oxide layer of the first structure;
• b) forming an etch mask having the etch pattern in the photoresist layer;
• c) positioning the first structure having the etch mask inside an etch reactor;
• d) exposing the C-doped silicon oxide layer to a plasma including :
• (1) CH2F2 gas flowing into the reactor at a first predetermined flow rate, (2) inert gas flowing into the reactor at a second predetermined flow rate and (3) a reactor bias energy no greater than about 400 W;
• and
• e) continuing exposing to the plasma until the pattern has been etched through the C-doped silicon oxide layer wherein a second structure is formed having a cavity in the C-doped silicon oxide layer such that the cavity exposes the silicon oxide layer as defined by the etch pattern.

A method of plasma etching a trench and a via in a first structure having a substrate upon which are sequentially formed a silicon oxide layer and a C-doped silicon oxide layer, the method comprising:

• a) depositing a first photoresist layer on the C-doped silicon oxide layer;
• b) forming a first etch mask having an via pattern in the first photoresist layer;
• c) anisotropically etching the via pattern through the C-doped silicon oxide layer and the silicon oxide layer, forming a cavity that exposes the substrate;
• d) removing the first photoresist, wherein a second structure is formed;
• e) forming a second photoresist layer on the second structure, wherein the second photoresist layer includes a second etch mask having a trench pattern that overlays the cavity;
• f) anisotropically etching the trench pattern through the C-doped silicon oxide layer forming a trench exposing the underlying via and the underlying silicon oxide layer, wherein etching the trench pattern comprises etching with a plasma including:
• (1) CH2F2 gas flowing at a first predetermined flow rate, (2) inert gas flowing at a second predetermined flow rate and (3) plasma conditions comprising (i) a bias energy no greater than about 400 W;
• and
• g) removing the second photoresist, wherein a third structure is formed that is adapted for forming a dual damascene structure therein.

A method of forming a structure on a substrate, the method comprising:

• a) depositing a silicon nitride layer on the substrate;
• b) depositing a first adhesive layer on the silicon nitride layer;
• c) depositing a silicon oxide layer on the first adhesive layer;
• d) depositing a second adhesive layer on the silicon oxide layer;
• e) depositing a layer of C-doped silicon oxide on the second adhesive layer;
• f) depositing a first photoresist layer on the C-doped silicon oxide layer;
• g) developing a via etch pattern in the photoresist layer;
• h) anisotropically etching the via etch pattern such that a hole is formed that exposes the silicon nitride layer;
• i) removing the first photoresist;
• j) depositing a second photoresist layer on the material layer;
• k) developing a trench pattern in the second photoresist layer such that the trench pattern overlays the hole;
• l) anisotropically etching the trench pattern through the C-doped silicon oxide layer and the second adhesive layer, comprising employing a plasma including (1) a gas mixture comprising CH2F2 and inert gas and (2) plasma conditions including
• (i) a bias energy range of about 250 to about 500 W and (ii) a pressure range of about 10 mT to about 90 mT, wherein a trench is formed overlaying a via and the silicon oxide layer.