Abstract: A method for making low sheet resistance local metal interconnections and improved transistor performance is described. The method involves patterning a polysilicon layer and a silicon nitride (Si3N4) cap layer over device areas to form FET gate electrodes, and the patterned polysilicon extends over the field oxide regions to form portions of the local interconnections. After forming source/drain areas and sidewall spacers on the FET gate electrodes, a silicon oxide (SiO2) insulating layer is deposited and polished back to the Si3N4 cap. The Si3N4 is then selectively removed over the patterned polysilicon layer, leaving recesses in the SiO2 layer. After etching contact openings in the SiO2 layer to the substrate, a high electrically conducting metal layer, having a barrier layer, is deposited and patterned to complete the local interconnections.

Abstract: A new method of forming air gaps between adjacent conducting lines of a semiconductor circuit by using a “holes everywhere” or a “reverse metal holes” mask that can be used to create holes in a dielectric layer. The dielectric that is being etched has been deposited across conducting lines, the holes that are being formed in this manner are closed by depositing a dielectric across the top of the holes. The holes can be etched across the entire layer of the deposited dielectric or can be etched in between the conducting lines.

Abstract: A method for the formation of an air gap structure for use in inter-metal applications. A metal pattern of metal lines is formed, a layer of Plasma Polymerized Methylsilane (PPMS) resist is deposited on top of this pattern. The surface of the PPMS resist is subjected to selective exposure. The unexposed PPMS is removed after which the process is completed by closing up the openings within the PPMS.

Abstract: A method of forming shallow trench isolation trenches for use with borderless contacts is achieved. A silicon nitride layer protects the shallow trench oxide layer from overetch damage. A silicon substrate is provided. A pad oxide layer is grown. A polishing stop layer, of polysilicon or silicon nitride, is deposited. The polishing stop layer, pad oxide layer, and silicon substrate are patterned to form the shallow trenches. A trench oxide layer is deposited to fill the shallow trenches. The trench oxide layer is polished down with the polishing stop layer as a polishing stop. The trench oxide layer is etched down to a level below that of the pad oxide layer. A silicon nitride layer is deposited. A polishing layer of oxide is deposited. The polishing layer and the silicon nitride layer are polished down with the polishing stop layer as a polishing stop. The polishing stop layer is etched away. The silicon nitride layer is etched to remove vertical sidewalls.

Abstract: A capacitor element of a semiconductor device used for high density semiconductor circuits is formed by the steps of forming the bottom plate of the capacitor, submitting the top of the bottom plate to plasma treatment in an oxidizing medium where nitrogen and oxygen are present, depositing a dielectric layer and submitting the top of the dielectric layer to plasma treatment in an oxidizing medium where nitrogen and oxygen are present. Various materials are used for the plasma treatment in an oxidizing medium where nitrogen and oxygen are present. While the present invention uses amorphous silicon as the dielectric material, plasma treatment in an oxidizing medium where nitrogen and oxygen are present can readily applied to a number of other dielectric materials.

Abstract: This invention relates to the new reversed flash memory device which has improved electrical performance, yield and reliability because of better control of the dielectric interfaces resulting from first making the poly 2 control gate within the silicon substrate. The reverse structure is novel, as are the described process methods for forming the reverse stacking order.Shallow trenched isolation (STI) is first formed in the p-silicon substrate and encompasses the poly 2 control gate region; then the interpoly dielectric is grown/deposited on that single crystal silicon substrate. The floating poly 1 is formed on top of this uniform interpoly dielectric that has well-controlled surface smoothness. The tunnel oxide layer is formed on the floating poly 1 layer, and the source/drain is implanted on a straddling additional poly layer. There are fewer edges and associated stress weaknesses in the dielectric breakdown of both the reversed interpoly dielectric and the floating tunnel oxide.