Apparatus with multidielectric spacers on conductive regions of stack structures, and related methods

Abstract

Apparatus (e.g., semiconductor devices) include stack structures with at least one conductive region and at least one nonconductive material. A multidielectric spacer is adjacent the at least one conductive region and comprises first and second dielectric materials. The first dielectric material, adjacent the at least one conductive region, includes silicon and nitrogen. The second dielectric material, adjacent the first dielectric material, comprises silicon-carbon bonds and defines a substantially straight, vertical, outer sidewall. In methods to form such apparatus, the first dielectric material may be formed with selectivity on the at least one conductive region, and the second dielectric material may be formulated and formed to exhibit etch resistance.

What is claimed is: 
     
         1 . An apparatus, comprising:
 at least one stack structure comprising at least one conductive region vertically between an upper nonconductive region and a lower semiconductive region;   a multidielectric spacer with a substantially straight, vertical, outer sidewall, the multidielectric spacer comprising:
 a first dielectric material extending directly along vertical sidewalls of the at least one conductive region, the first dielectric material comprising silicon and nitrogen; and 
 a second dielectric material extending directly along the first dielectric material, the second dielectric material comprising silicon-carbon bonds, 
 the first dielectric material or the second dielectric material further extending directly along vertical sidewalls of the lower semiconductive region at a base of the at least one stack structure. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the first dielectric material further extends directly along the vertical sidewalls of the lower semiconductive region at the base of the at least one stack structure, the first dielectric material providing a continuous material region along an entire height of the at least one stack structure. 
     
     
         3 . The apparatus of  claim 1 , wherein the second dielectric material further extends directly along the vertical sidewalls of the lower semiconductive region at the base of the at least one stack structure, the second dielectric material providing a continuous material region along an entire height of the at least one stack structure. 
     
     
         4 . The apparatus of  claim 3 , wherein:
 substantially none of the first dielectric material extends onto vertical sidewalls of the upper nonconductive region; and   substantially none of the first dielectric material extends onto the vertical sidewalls of the lower semiconductive region.   
     
     
         5 . The apparatus of  claim 1 , wherein a greatest thickness of the first dielectric material is defined along the vertical sidewalls of at least one of the at least one conductive regions. 
     
     
         6 . The apparatus of  claim 1 , wherein the at least one stack structure defines a height-to-width ratio of at least about 15:1. 
     
     
         7 . The apparatus of  claim 1 , further comprising an inhibitor on vertical sidewalls of at least the upper nonconductive region and not on the vertical sidewalls of the at least one conductive region. 
     
     
         8 . The apparatus of  claim 7 , wherein the inhibitor comprises at least one of: a silane and a fluoride-containing material. 
     
     
         9 . The apparatus of  claim 1 , wherein:
 the second dielectric material comprises at least about 5 wt. % carbon; and   the first dielectric material is substantially free of carbon.   
     
     
         10 . A method of forming an apparatus comprising insulated conductive regions, comprising:
 forming at least one stack structure comprising at least one conductive region vertically between an upper nonconductive region and a lower semiconductive region   forming a first dielectric material directly along vertical sidewalls of the at least one conductive region, the first dielectric material comprising silicon and nitrogen; and   forming a second dielectric material directly along the first dielectric material, the second dielectric material comprising silicon-carbon bonds,   the second dielectric material defining a substantially straight, vertical, outer sidewall, and   the first dielectric material or the second dielectric material further extending directly along vertical sidewalls of the lower semiconductive region at a base of the at least one stack structure.   
     
     
         11 . The method of  claim 10 , wherein forming the first dielectric material comprises forming, by atomic layer deposition, silicon nitride. 
     
     
         12 . The method of  claim 11 , further comprising, before forming the second dielectric material, exposing the silicon nitride to air to at least partially convert the silicon nitride to silicon oxynitride or silicon dioxide. 
     
     
         13 . The method of  claim 10 , wherein forming the first dielectric material comprises forming the first dielectric material by atomic layer deposition with at least one precursor selected from the group consisting of silicon bromide, silicon iodide, SiH 4 , CH 4 , and silanes. 
     
     
         14 . The method of  claim 13 , wherein forming the first dielectric material comprises forming silicon nitride, silicon oxynitride, or silicon carbide. 
     
     
         15 . The method of  claim 10 , further comprising, before forming the first dielectric material:
 exposing the at least one stack structure to ammonia, a fluorine-containing gas, and a plasma to form fluorine-containing compounds on the vertical sidewalls of the at least one conductive region; and   removing the fluorine-containing compounds.   
     
     
         16 . The method of  claim 15 , further comprising, after removing the fluorine-containing compounds and before forming the first dielectric material, applying a silane or a silane-containing material to exposed surfaces of upper nonconductive region. 
     
     
         17 . The method of  claim 10 , further comprising, before forming the first dielectric material, applying a silane or a silane-containing material to exposed surfaces of the upper nonconductive region. 
     
     
         18 . A method of forming an apparatus with electrically insulated conductive regions, the method comprising:
 forming at least one conductive material above a semiconductive material;   forming a nonconductive material above the at least one conductive material;   patterning the at least one conductive material, the nonconductive material, and the semiconductive material to define a precursor structure comprising stack structures each comprising at least one conductive region vertically between an upper nonconductive region and a lower semiconductive region, the at least one conductive region comprising the at least one conductive material, the upper nonconductive region comprising the nonconductive material, and the lower semiconductive region comprising the semiconductive material;   selectively forming a first dielectric material directly on an exposed surface of the at least one conductive material, the first dielectric material comprising silicon and nitrogen;   forming a second dielectric material directly on the first dielectric material, the second dielectric material comprising silicon-carbon bonds and at least five atomic percent carbon,   the second dielectric material defining a substantially straight, vertical, outer sidewall, and   the first dielectric material or the second dielectric extending directly on vertical sidewalls of the lower semiconductive region.   
     
     
         19 . The method of  claim 18 , further comprising, forming a silane or a silane-containing material directly on the nonconductive material before selectively forming the first dielectric material. 
     
     
         20 . The method of  claim 18 , wherein selectively forming the first dielectric material comprises selectively forming the first dielectric material to define a greatest thickness thereof along at least one of the at least one conductive material.