This talk will explain definition of exposure parameter setting up an exposure details on exposure parameter

RAITH uses Round beam with Gaussian-shaped profile moved along line = name vector scan Writing strategy

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

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

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

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,... Exposure parameters

Parameter AreaLineDot beam currentyesyesyes doseyesyesyes dwell timeyesyesyes step sizeyesyesno selectable332 determined111 under the condition to clear or equivalently fulfill the dose equation. Exposure parameters

Central window to set up all exposure parameters calculated step size and dwel time Calculator using clearing dose and beam current Software – Exposure module

Window to perform calculation beam current and dose start calculation Software – Calculator

Pull design into positionlist with Drag and Drop Software – Exposure

Right mouse click then open properties Software – Positionlist

calculated parameters as in Exposure module choose to expand dialog Software – Positionlist

to use parameters from Exposure module place tick Software – Positionlist

to use individual parameters, remove ticks and press Calculator Software – Positionlist

dwell time at each position can be re- scaled using dose factor Software – Positionlist

opens dialog to set these parameters Loops Line mode Meander mode Settling time Flyback time Circular mode Software – Exposure Details

Loops Exposure raster Line/Meander Scan direction Settling time Flyback time Circular mode Software – Exposure Details

Each write field is repeated n times. (0 means infinite number of loops) Exposure Details - Loops

Fixed sets basic step size to 2.0 nm Free allows selection of basic step size for better placement accuracy Exposure Details - Raster

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 “Exposure parameters” for hints which mode to use. Exposure Details – Area Mode

In Automatic mode, the beam is scanned along the side of greatest length In Manual mode, you can select the direction of the that the beam is scanned Exposure Details – Scan direction

Settling time = waiting period at beginning of each element Flyback time = waiting period between lines. Please note, in our software Flyback time = settling time  flyback factor Exposure Details – Settling/Flyback time

Circular mode = round elements are decomposed into dots dots are exposed in centric rings vertices are not used Exposure parameters = Uses area parameters Exposure Details – Circular mode

Exposure Details – Dynamic compensation Addresses the issue of the nominal and physical position of the beam during an exposure with respect to the sample surface