HiCUM Model Version 2.40

Following updates have been made in Version 2.40:

• New CMC model versioning policy is adopted:
  <version #>.<subversion #>.<revision#>
• Improvised collector avalanche equation
• Backward compatibility and application
• Introduction of conditional statement for weak avalanche breakdown
• Addition of Gmin for operating point values
• Renamed the operating point value names of resistance, RE and RCX by re_t and rcx_t
• Improvised calculation of Vciei

Improvised Strong Collector Avalanche Formula

The new formulation for strong collector avalanche breakdown is given by:

Formula based on weak avalanche:

With addition parameter , kAVL is modeled temperature dependent by:

With the smoothening model parameter fixed to 0.01, the denominator is limited to values greater than zero by the smoothening function:

Parameter Extraction

You can extract kAVL as:

Conditional Statement for Weak Avalanche

Improvised conditional statement based on based on favl and cjci0 and not favl_t and cjci0_t:

if ((favl > 0.0) && (cjci0 > 0.0)) begin
use_aval = 1;
end else begin
use_aval = 0;
iavl = 0.0;
end

Usage of an integer flag results in faster evaluation of the if-statement:

if(use_aval == 1) begin : HICAVL

Setting iavl = 0.0 during model initialization avoids the additional else block for this if-statement.

Backward Compatibility and Application

• Extension is completely compatible to previous HICUM versions.
• Values for weak avalanche model parameters fAVL and qAVL can be re-used to extend existing model cards by the new feature.
• Application of experimental data:
  • favl and qavl are used for 2.34 and 2.4.0
  • New parameters: kavl = 0.088 and alkav=0.0037
    
    
    

Improvised Vciei Calculation

For model compilers with derivatives based on branches, variables for the high-current region dependent on four branches, bi,ei, bi,ci, ci,ei, and t,gnd, Vciei will be calculated as:

Vciei = Vbiei-Vbici

This calculation removes the dependence on the ci,ei branch and reduces number of derivatives for each variable to three.

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