#--- Initial Grid ----------------------------------------------------# Note: In sprocess "x" refers to the vertical direction and "y" refers to the h orizontal direction. # You can specify the initial grid definition and tags to certain positions here . For example, the grid spacing in between x=0nm and x=50nm is 1nm. Similarly, t he grid spacing from 100nm to 600nm is 50nm. In the statement "line x location=6 00 spacing=100 tag=SiBottom", the spacing = 100nm will be used only if the vertical axis extents beyond 600nm and it does not extend in this example. # x=0nm is given a tag "SiTop" and x=600nm is given a tag "SiBottom" line line line line x x x x location= 0.0 location=50 location=100 location=600 spacing=1.0 tag=SiTop spacing=10 spacing=50 spacing=100 tag=SiBottom

line y location=0.0 spacing=50 tag=Mid line y location=300 spacing=50 tag=Right # --- Silicon substrate definition ------------------------------------# We started with a substrate with Silicon. This need not be Silicon always. For example you can start with Oxide substrate OR with a substrate with oxide and S ilicon. In this case you may need to define two region statements one for Oxide and one for Silicon. region Silicon xlo=SiTop xhi=SiBottom ylo=Mid yhi=Right # --- Initialize the simulation ---------------------------------------# All the initial parameters that the simulator assumes are listed here. init concentration=1e+17 field=Boron wafer.orient=100 # --- MGOALS settings for automatic meshing in newly generated layers # MGOALS is a meshing engine of sprocess and you can specify how adaptive the me sh can be while adding new layers. For example in the statement below, we have s pecified that the min. mesh spacing should be 2nm when a new layer is added on t op of Silicon and this spacing can increase at a rate of 1.4. mgoals min.normal.size=2 normal.growth.ratio=1.4 accuracy=1e-5 # --- Oxide deposition --------------------------------------------------# "deposit" command is used to deposit any material on top. You can specify the type of deposition and the thickness of the layer to be deposited here. Instead of specifying the thickness in the deposition time and deposition rate, you can also directly specify the thickness of the material to be deposited in nm. i.e., "time=1 rate= {0.01}" in the statement below can be replaced by "thickness=10nm ". After any deposition or etch process, it is advised to regrid the mesh. deposit material= {Oxide} type=isotropic time=1 rate= {0.01} grid remesh #--- mask definition ------------------------------------------deposit material= {Nitride} type=isotropic time=1 rate= {0.2} # In the statement below, we have defined a mask with name "implant_mask" that c overs from 0nm to 100nm and 200nm to 300nm in the horizontal direction. Note: Th is mask will be effective only if we use it along with a "deposit" OR "etch" or "implant" step.

mask name=implant_mask segments= {0 0.10 0.20 0.30 } # In the statement below, we are asking the simulator the etch 300nm of Nitride from the regions that are not covered by "implant_mask". Implant mask defined in the statement above does not cover from 200nm to 300nm. Hence a 300nm of Nitrid e is etched from the substrate in the region from 200nm to 300nm in the horizont al direction. etch material= {Nitride} type=anisotropic time=3 rate= {0.1} mask=implant_mask # --- Saving structure ------------------------------------------------# You can save the structure in between the process simulation to visualize it i n tecplot. The below statement saves the structure in tdr format with name "pp_1 _fps.tdr" struct tdr=pn_1 # Ion implantation is done in the following statement. Implant conditions like e nergy, dose, tilt, etc., need to be specified along with the implant statement. implant Phosphorus energy=8.4 dose=1.2e13 tilt = 0 #--- Saving structure ------------------------------------------------struct tdr=pn_2 ; # the following statement is included to activate the dopants via a rapid therma l anneal process. Note: Any high temperature thermal step not only activates the dopants, but also diffuses the dopants into the less doped regions. The length by which the dopants diffuse depends on the values on temperature and time. #--- n-type: RTA of channel implants ---------------------------------diffuse temperature=1060 time=12 #--- Saving structure ------------------------------------------------struct tdr=pn_3 ; # GateOx etch material= {Nitride} type=isotropic time=10 rate= {0.1} etch material= {Oxide} type=isotropic time=10 rate= {0.1} grid remesh # In addition to the grid defined in the begining of this file, we can at any ti me re-define the grid in a region if interest. For example, in the below stateme nt, we have identified the region where the junctions extends and have defined a dense grid with x and y spacing as 5nm. #--- Junction refinement ------------------------------------------------refinebox Silicon min= {0.0 0.05} max= {0.055 0.26} \ xrefine= {0.005 0.005 0.005} yrefine= {0.005 0.005 0.005} grid remesh #--- Contact metal deposition -------------------------------------------------------deposit material= {Aluminum} type=isotropic time=1 rate= {0.07} mask name=contacts_mask1 left=0.12 right=0.15 etch material= {Aluminum} type=anisotropic time=1 rate= {0.08} mask=contacts_mas k1 grid remesh

# The below statement saves the structure before the actual contact definition. struct tdr=pn_before_contacts #------- Definition of contacts # The same contact names that we use here should be used in the device simulatio ns later on. contact name = "n" box Aluminum adjacent.material = Ambient \ xlo = -0.03 xhi = -0.07 ylo = 0.119 yhi = 0.151 contact name = "p" box silicon adjacent.material = Ambient\ xlo = 0.6 xhi = 0.7 ylo = 0.0 yhi = 0.3 # We save the final structure after contacts and this is the structure that is s upposed to be used in subsequent device simulations. struct tdr = PN_final