Specific Process Knowledge/Lithography/EBeamLithography/Dose Testing: Difference between revisions
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=Dose modulation in JDF= | =Dose modulation in JDF= | ||
<pre> | |||
MAGAZIN 'FIRSTEBL' The magazine name is FIRSTEBL; max. 9 capital letters | |||
#8 Cassette from auto stocker shelf 8 is used | |||
%4B 4" wafer in position A is exposed | |||
JDF 'myfirstebl',1 Layer block no. 1 of the jdf-file 'myfirstebl.jdf' is exposed | |||
ACC 100 Acceleration voltage of 100keV is used (can not be changed) | |||
CALPRM '6na_ap5' The condition file 6na_ap5 is used, i.e. exposure at 6 nA | |||
DEFMODE 2 Both deflectors are used (default) | |||
RESIST 200 A base dose of 200 µC/cm2 is used | |||
SHOT A,16 Shot pitch is 16 units (of 0.25 nm), i.e. 4 nm | |||
OFFSET(0,0) An offset of 0 µm is applied in both X and Y | |||
END 8 After exposure, cassette 8 will be remain on the stage | |||
</pre> | |||
Pattern placement is controlled with the ARRAY command in the JDF. The goal of this example exposure is to create a dose test and thus we will use the ARRAY command to create an array of the pattern (the DTU logo) and we will use the MODULAT command to modulate the dose for each instance in the array. The ARRAY command takes six parameters as ARRAY(x,nx,dx)/(y,ny,dy), where x and y defines the center of the first element, nx and ny defines element numbers and dx and dy defines the array element pitch. The array defined in the example below will create a 10 x 1 array with an x-axis pitch of 50 µm. | |||
Each array element is assigned a dose modulation using the MODULAT command. The MODULAT command takes two parameters as MODULAT(r,v), where r is the shot rank and v is the shot time modulation in %. The shot rank is defined during export from Beamer. For a simple design as used in this example that is not proximity corrected all elements of the pattern will be in shot rank 0. If a design is proximity corrected pattern elements will be assigned to different shot ranks. The shot time modulation is a simple percentage increase to the base dose defined by the RESIST command in the SDF. The modulation table in this example will thus expose with a base dose of 200 µC/cm<sup>2</sup> in element (1,1) and a dose of 200 µC/cm<sup>2</sup> + 45% = 290 µC/cm<sup>2</sup> in element (10,1). The resulting pattern and modulation is visualised below. | |||
<pre> | |||
JOB/W 'FIRSTEBL',4 4inch wafer | |||
PATH DRF5M Cyclic calibration definition | |||
ARRAY (50,10,50)/(50,1,0) 10-1 array around (50,50) with 50 µm pitch in x-axis | |||
ASSIGN P(1)->((1,1),SHOT1) Pattern and modulation assignment to each array element | |||
ASSIGN P(1)->((2,1),SHOT2) | |||
ASSIGN P(1)->((3,1),SHOT3) | |||
ASSIGN P(1)->((4,1),SHOT4) | |||
ASSIGN P(1)->((5,1),SHOT5) | |||
ASSIGN P(1)->((6,1),SHOT6) | |||
ASSIGN P(1)->((7,1),SHOT7) | |||
ASSIGN P(1)->((8,1),SHOT8) | |||
ASSIGN P(1)->((9,1),SHOT9) | |||
ASSIGN P(1)->((10,1),SHOT10) | |||
AEND | |||
PEND | |||
LAYER 1 Definition of pseudo layer 1 | |||
P(1) 'dtu_logo_um.v30' Assignment of P(1) to V30 file | |||
SPPRM 4.0,,,,1.0,1 Beam parameters | |||
STDCUR 2.2 ;nA Beam current + 10% overhead | |||
SHOT1: MODULAT (( 0,0)) Dose modulation tables | |||
SHOT2: MODULAT (( 0,5)) | |||
SHOT3: MODULAT (( 0,10)) | |||
SHOT4: MODULAT (( 0,15)) | |||
SHOT5: MODULAT (( 0,20)) | |||
SHOT6: MODULAT (( 0,25)) | |||
SHOT7: MODULAT (( 0,30)) | |||
SHOT8: MODULAT (( 0,35)) | |||
SHOT9: MODULAT (( 0,40)) | |||
SHOT10: MODULAT (( 0,45)) | |||
END | |||
</pre> | |||
{| style="border: none; border-spacing: 0; margin: 1em auto; text-align: center;" | |||
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| [[image:DoseArray.png|1000px]] | |||
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| colspan="1" style="text-align:center;| | |||
Resulting setup from the example job. The pattern (DTU logo) is instanced 10 times with a pitch of 50 µm. The dose is modulated between 200 and 290 µC/cm<sup>2</sup>. Pattern size is increased for visibility, actual size is 5 x 8 µm<sup>2</sup>. | |||
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=Using Chipplace in Beamer= | =Using Chipplace in Beamer= | ||