| 摘要 |
<p>A method to determine a desired thickness for a surface layer 128 through which ion implantation into a substrate will take place in order to control the shape of the implantation profile 130 to minimize the formation of flaws, includes choosing a maximum angle # between solid phase epitaxial regrowth fronts, determining a projected range of ion implantation distance Rp and a projected standard deviation #Rp along a first axis direction and a projected standard deviation #Y along a second axis direction. These values are then substituted into the following equation to solve for thickness t of the surface layer: t = Rp + cos#[[(#Ysin#)<SP>2</SP> + (#Rpcos#)<SP>2</SP>]<SP>0.5</SP>] After the layer 128 is placed onto the substrate, the implantation step is carried out. Annealing is then performed to recrystallize the amorphous zone. The morphology of the surface layer 128 and/or the substrate 132 can alternatively or additionally be modified, e.g. by forming a concove depression in order to control the directions of recrystallization upon annealing. The method can be used in the formation of a bit line contact for a DRAM.</p> |
