摘要:
A process for plasma etching of contact and via openings in low-k organic polymer dielectric layers is described which overcomes problems of sidewall bowing and hardmask pattern deterioration by etching the organic layer in a high density plasma etcher with a chlorine/inert gas plasma. By adding chlorine to the oxygen/inert gas plasma, the development of an angular aspect or faceting of the hardmask pattern edges by ion bombardment is abated. Essentially vertical sidewalls are obtained in the openings etched in the organic polymer layer while hardmask pattern integrity is maintained. The addition of a passivating agent such as nitrogen, BCl.sub.3, or CHF.sub.3 to the etchant gas mixture further improves the sidewall profile by reducing bowing through protective polymer formation.
摘要:
A novel method of dual damascene etching is disclosed. It is shown that the performance of ULSI circuits can be improved by shrinking interconnect dimensions through the use of dual damascene processes, using hard-masks to achieve vertical walls and hence smaller spaces in the damascene structures, introducing low-k (dielectric constant) insulating materials to reduce RC delays, and metallizing with copper without the deleterious effects of bridging after CMP. These are accomplished by using a novel recipe for etching the hard-masks used in a dual damascene process and still another recipe for etching low-k dielectric layers in three different combinations with oxide-based dielectric layers.
摘要:
A new method of etching metal lines using HCl in the overetch step to prevent undercutting of the metal lines is described. Semiconductor device structures are provided in and on a semiconductor substrate. The semiconductor device structures are covered with an insulating layer. A barrier metal layer is deposited overlying the insulating layer. A metal layer is deposited overlying the barrier metal layer. A hard mask layer is deposited overlying the metal layer. The hard mask layer is covered with a layer of photoresist which is exposed, developed, and patterned to form the desired photoresist mask. The hard mask layer is etched away where it is not covered by the photoresist mask leaving a patterned hard mask. The metal layer is etched away where it is not covered by the patterned hard mask to form the metal lines. Overetching is performed to remove the barrier layer where it is not covered by the hard mask wherein HCl gas is one of the etchant gases used in the overetching whereby hydrogen ions from the HCl gas react with the metal layer and the barrier metal layer to form a passivation layer on the sidewalls of the metal lines thereby preventing undercutting of the metal lines resulting in metal lines having a vertical profile. The photoresist mask is removed and fabrication of the integrated circuit device is completed.
摘要:
A method for etching of sub-quarter micron openings in insulative layers for contacts and vias is described. The method uses hardmask formed of carbon enriched titanium nitride. The hardmask has a high selectivity for etching contact and via openings in relatively thick insulative layers. The high selectivity requires a relatively thin hardmask which can be readily patterned by thin photoresist masks, making the process highly desirable for DUV photolithography. The hardmask is formed by MOCVD using a metallorganic titanium precursor. By proper selection of the MOCVD deposition conditions, a controlled amount of carbon is incorporated into the TiN film. The carbon is released as the hardmask erodes during plasma etching and participates in the formation of a protective polymer coating along the sidewalls of the opening being etched in the insulative layer. The protective sidewall polymer inhibits lateral chemical etching and results in openings with smooth, straight, and near-vertical sidewalls without loss of dimensional integrity.
摘要:
A method is achieved for fabricating small contact holes in an interlevel dielectric (ILD) layer for integrated circuits. The method increases the ILD etch rate while reducing residue build-up on the contact hole sidewall. This provides a very desirable process for making contact holes small than 0.25 um in width. After depositing the ILD layer over the partially completed integrated circuit which includes patterned doped first polysilicon layers, a second polysilicon layer is deposited and doped with carbon by ion implantation. A photoresist mask is used to etch openings in the carbon doped polysilicon layer to form a hard mask. The photoresist is removed, and the contact holes are plasma etched in the ILD layer while free carbon released from the hard mask, during etching, reduces the free oxygen in the plasma. This results in an enhanced fluorine (F.sup.+) etch rate for the contact holes in the ILD layer and reduces the residue build-up on the sidewalls of the contact holes. The hard mask is anneal in O.sub.2 to form an oxide layer and any surface carbon is removed in a wet etch. Reliable metal plugs can now be formed by depositing a barrier layer, such as titanium (Ti) or titanium nitride (TiN) and a metal such as tungsten (W) and etching back or chemical/mechanical polishing back to the oxide layer.
摘要:
A method for forming a chlorine containing plasma etched patterned layer. There is first provided a substrate 10 employed within a microelectronics fabrication. There is then formed over the substrate a blanket target layer 12 formed of a material susceptible to etching within a second plasma employing a chlorine containing etchant gas composition. There is then formed upon the blanket target a blanket hard mask layer 14 formed of a material selected from the group consisting of silsesquioxane spin-on-glass (SOG) materials and amorphous carbon materials. There is then formed upon the blanket hard mask layer a patterned photoresist layer 16. There is then etched while employing the patterned photoresist layer as a first etch mask layer and while employing a first plasma employing a fluorine containing etchant gas composition the blanket hard mask layer to form a patterned hard mask layer. Finally, there is then etched while employing at least the patterned hard mask layer as a second etch mask layer and while employing the second plasma employing the chlorine containing etchant gas composition the blanket target layer to form the patterned target layer.
摘要:
A new method of forming a dual damascene interconnect is disclosed for manufacturing semiconductor substrates. A contact/via hole is first formed in a first dielectric layer formed over a substructure of a substrate having devices formed therein and/or metal layers formed thereon. The contact/via hole is filled with a protective material prior to forming a second dielectric layer. Conductive line opening is formed in the second dielectric layer and over the contact/via hole having the protective material in it. The protective material protects the edge of the contact/via hole from damage due to the second etching of the conductive line opening. Thus, a dual damascene structure is disclosed wherein the integrity of the edge of the contact/via hole is preserved, avoiding any reliability problems in the semiconductor product.
摘要:
The present invention provides a method improving the adhesion between inter metal dielectric (IMD) layers by performing a HF dip etch to treat the surface of an oxide, silicon nitride or Silicon oxynitride insulating layer before an overlying low-K layer is formed. The present invention provides a method of fabricating a low-K IMD layer 20 over an oxide, Silicon oxynitride (SiON), or nitride IMD layer 14 with improved adhesion. First, a 1st inter metal dielectric (IMD) layer 14 is formed over a substrate. Next, the invention's novel HF dip etch is performed on the 1st IMD layer 14 to form a treated surface 16. Next, a 2nd BMD layer composed of a low-K material is formed over the rough surface 16 of the 1st IMD layer 14. The treated surface 16 improves the adhesion between a 1st IMD layer oxide (oxide, SiN or SiON) and a low k layer. Subsequent photoresist strip steps do not cause the 1st IMI layer 14 and the 2nd IMD layer 20 (low-K dielectric) to peel.
摘要:
I A method is achieved for removing a hardmask from a feature on a semiconductor wafer. The method comprises the following phases: depositing a buffer layer overall; etching back the buffer layer in an etching apparatus to expose the hardmask; etching the hardmask in the etching apparatus; and etching of the remaining buffer layer in the etching apparatus.
摘要:
Current aqueous methods for removal of polymeric materials from the sidewalls of trenches etched into silicon wafers by reactive-ion-etching are inadequate for treating deep trenches having high aspect ratios. Spin-dry operations performed after the aqueous etching are incapable of completely removing rinse water and ionic species from these deep trenches, thereby leaving pockets of liquid. Subsequent evaporation of these pockets results in the concentration and eventual precipitation of residual ionic species creating watermarks. A two stage cleaning method is described in which the first stage dissolves the sidewall polymer and the second stage draws ionic species strongly chemisorbed onto the silicon surfaces into solution. A key feature of the method is that the wafer surface is not permitted to dry until after the final rinse.