Diffusion barrier process for routing polysilicon contacts to a metallization layer

A method of forming polysilicon and metal contact plugs, comprising:

• forming an insulation layer overlying an active area of an integrated circuit;
• forming one or more first and second contact holes in the insulation layer;
• forming a polysilicon layer over the insulation layer in contact with the active area through the one or more first contact holes;
• removing a portion of the polysilicon layer to form one or more polysilicon contact plugs in the one or more contact holes, wherein a top surface of each of the one or more polysilicon contact plugs are formed below a top surface of the insulation layer;
• forming a contact liner material layer over the insulation layer in contact with the top surface of each of the one or more polysilicon contact plugs and second contact holes;
• and
• removing a portion of the contact liner material layer to form a diffusion barrier over each polysilicon contact plug in the one or more contact holes and one or more metal contact plugs in the one or more second contact holes.

A method of fabricating a memory array, comprising:

• forming an interlayer dielectric (ILD) isolation stack overlying an active area of memory array;
• forming one or more first and second contact holes in the ILD isolation stack;
• forming a polysilicon layer over the ILD isolation stack in contact with the silicon active area through the one or more first contact holes;
• removing a portion of the polysilicon layer to form one or more polysilicon contact plugs in the one or more first contact holes, wherein a top surface of each of the one or more polysilicon contact plugs are formed below a top surface of the ILD isolation stack;
• forming a contact liner material layer over the ILD isolation stack in contact with the top surface of each of the one or more polysilicon contact plugs and the active area through the one or more second contact holes;
• and
• removing a portion of the contact liner material layer to form a diffusion barrier over each polysilicon contact plug in the one or more contact holes and form one or more metal contact plugs in the one or more second contact holes.

A method of forming an integrated circuit, comprising:

• forming the active area of a memory array containing a plurality of floating gate memory cells;
• forming an insulation layer overlying the active area;
• forming one or more first and second contact holes in the insulation layer;
• forming a polysilicon layer over the insulation layer in contact with the active area through the one or more first contact holes;
• removing a portion of the polysilicon layer to form one or more polysilicon contact plugs in the one or more first contact holes, wherein a top surface of each of the one or more polysilicon contact plugs are formed below a top surface of the insulation layer;
• forming one or more metal contact plugs in the one or more second contact holes;
• forming a contact liner material layer over the insulation layer in contact with the top surface of each of the one or more polysilicon contact plugs and one or more metal contact plugs;
• and
• removing a portion of the contact liner material layer to form a diffusion barrier over each polysilicon contact plug and metal contact plug.

A method of forming a Flash memory device, comprising:

• forming the silicon active area of a memory array containing a plurality of floating gate memory cells;
• forming an interlayer dielectric (ILD) isolation stack overlying the silicon active area;
• forming one or more first and second contact holes in the ILD isolation stack;
• forming a polysilicon layer over the ILD isolation stack in contact with the silicon active area through the one or more first contact holes;
• removing a portion of the polysilicon layer to form one or more polysilicon contact plugs in the one or more first contact holes, wherein a top surface of each of the one or more polysilicon contact plugs are formed below a top surface of the ILD isolation stack;
• forming one or more metal contact plugs in the one or more second contact holes;
• forming a contact liner material layer over the ILD isolation stack in contact with the top surface of each of the one or more polysilicon and metal contact plugs;
• and
• removing a portion of the contact liner material layer to form a diffusion barrier over the polysilicon and metal contact plugs.

A method of forming a portion of an integrated circuit, comprising:

• forming a dielectric layer overlying a silicon active area of the integrated circuit;
• forming a contact hole in the dielectric layer exposing a portion of the silicon active area;
• forming a polysilicon layer overlying the dielectric layer and contacting the portion of the silicon active area;
• removing a portion of the polysilicon layer to leave a polysilicon plug in the contact hole, wherein a top surface of the polysilicon plug is recessed below a surface of the dielectric layer;
• and
• forming a layer of barrier material overlying the dielectric layer and contacting the surface of the polysilicon plug, filling the formed recess between the top surface of the polysilicon plug and the surface of the dielectric layer;
• and
• removing a portion of the barrier layer to leave portions of the barrier layer in the formed recess of the contact hole between the surface of the dielectric layer and the top surface of the polysilicon plug.

A method of forming polysilicon contact plugs, comprising:

• forming an insulation layer overlying an active area of an integrated circuit;
• forming one or more contact holes in the insulation layer;
• forming a polysilicon layer over the insulation layer in contact with the active area through the one or more contact holes;
• removing a portion of the polysilicon layer to form one or more polysilicon contact plugs in the one or more contact holes, wherein a top surface of each of the one or more polysilicon contact plugs are formed below a top surface of the insulation layer;
• and
• forming a contact liner material layer over the insulation layer in contact with the top surface of each of the one or more polysilicon contact plugs to form a diffusion barrier over each polysilicon contact plug in the one or more contact holes.