Copyright 2013 by Raith Pattern Writing with the NanoSuite Software
Copyright 2013 by Raith RAITH uses Round beam with Gaussian-shaped profile moved along line = name vector scan Writing strategy
Copyright 2013 by Raith number of electrons beam current dwell time = T dwell I beam Unit is µAs/cm² area step size 2 = s 2 Rule: To clear an area a certain number of electrons have to hit the sample within a certain area = clearing area dose s s Area exposure - Dose
Copyright 2013 by Raith Unit is pAs/cm Rule: To clear an line a certain number of electrons have to hit the sample within a certain length = clearing line dose number of electrons beam current dwell time = T dwell I beam line step size = s s Line exposure - Dose
Copyright 2013 by Raith Unit is pAs Rule: To clear an line a certain number of electrons have to hit the sample within a certain point = clearing dot dose number of electrons beam current dwell time = T dwell I beam Dot exposure - Dose
Copyright 2013 by Raith beam current defined by column, i.e. filament, aperture, voltage,... dose defined by process, i.e. resist, developer, temperature,... dwell time and step size exposure parameters defined by your needs, e.g. accuracy, GDSII, throughput,... Patterning parameters
Copyright 2013 by Raith Parameter AreaLineDot beam currentyesyesyes doseyesyesyes dwell timeyesyesyes step sizeyesyesno selectable332 determined111 under the condition to clear or equivalently fulfill the dose equation. Patterning parameters
Copyright 2013 by Raith Central window to set up all exposure parameters calculated step size and dwell time Calculator using clearing dose and beam current Software – Patterning module
Copyright 2013 by Raith Window to perform calculation beam current and dose start calculation Software Calculator
Copyright 2013 by Raith Pull design into positionlist with Drag and Drop Software Patterning
Copyright 2013 by Raith Right mouse click then open properties Software - Positionlist
Copyright 2013 by Raith calculated parameters as in Exposure module choose to expand dialog Software - Positionlist
Copyright 2013 by Raith to use parameters from Exposure module place tick Software - Positionlist
Copyright 2013 by Raith to use individual parameters, remove ticks and press Calculator Software - Positionlist
Copyright 2013 by Raith dwell time at each position can be re- scaled using dose factor Software - Positionlist
Copyright 2013 by Raith opens dialog to set these parameters Loops Patterning Raster Area mode (line or meander) Settling time Advanced parameters Drift compensation Visualization Software – Patterning Details
Copyright 2013 by Raith Each write field is repeated n times. (0 means infinite number of loops) Patterning Details - Loops
Copyright 2013 by Raith Fixed sets basic step size to 1.6 nm Free allows selection of basic step size for better placement accuracy Patterning Details - Raster
Copyright 2013 by Raith = DAC Range nm nm nm Basic Step Size Writefield Size = 100 µm Non Metric Raster Fixed Metric Raster Free Metric Raster Patterning Details - Raster
Copyright 2013 by Raith Line mode = element is filled with each line from the same direction. Meander mode = element is filled with each line from the opposite direction. See talk “Patterning parameters” for hints which mode to use. Patterning Details – Area Mode
Copyright 2013 by Raith Patterning Details – New Area Modes longitudinal mode basic structure to pattern transversal mode angle mode axes mode – preset U Fracturing adapted for the new area fill modes concentric mode
Copyright 2013 by Raith Settling time = waiting period at beginning of each line Patterning Details – Settling time Software realizes automtically the jump distance and sets settling time automatically Manual: Always the set settling time is applied
Copyright 2013 by Raith Circular mode = round elements are decomposed into dots dots are exposed in centric rings vertices are not used Exposure parameters = Uses curved elements parameters Patterning Details – Circular Mode
Copyright 2013 by Raith Patterning Details – Curved elements Curved elements – separate pattern parameters 2 ways to fill
Copyright 2013 by Raith Addresses the issue of the nominal and physical position of the beam during an exposure with respect to the sample surface Patterning Details – Dynamic Compensation
Copyright 2013 by Raith Patterning Details – Drift Compensation Allows user to check and make corrections to beam current, beam position Allows user to check column parameters
Copyright 2013 by Raith Patterning Details – Visualization
Copyright 2013 by Raith Definitions for bitmap (8 bit) as reference only. Patterning Details – Referenced Grayscale bitmap