This page updated 12 Sept 2014

General Information

Historical background

The Bipole3 software originated in the late 1970s. It was developed by Professor David Roulston as a tool for assisting in the design of advanced bipolar transistors for industry. This work was initially carried out both at the University of Waterloo and as a consultant at Thomson-CSF in France (subsequently SGS-Thomson, now STMicroelectronics). The project continued with significant input from researchers at the University of Waterloo backed up by substantial development cooperation from the French firm with laboratories in Corbeville, Aix-en-Provence, Grenoble and more recently Crolles.

BIPOLE3, now available directly from the University of Waterloo, has been extensively expanded and upgraded in the past few years and now offers high precision quasi three dimensional numerical simulation of a range of semiconductor bipolar devices including discrete bipolar transistors, integrated BJTs, SiGe HBTs, diodes and MOSFETs. The program has been widely evaluated in industry in close cooperation with BIPSIM Inc. and the University of Waterloo and is now used as a high performance software package for predicting the terminal (d.c., small signal and h.f.) characteristics of bipolar transistors including all major three dimensional effects.

BIPOLE3 is designed specifically for bipolar transistors and diodes (with a separate MOSFET option), and is not a generalised semiconductor device solver. Because of this fact, the simulation is possible with an execution time which is of order 1/100th that of a full 2D simulator (and includes many important third dimension effects not taken into account in conventional 'full' 2D simulation).

The high speed is accomplished by combining two solution techniques:

(a) judicious coupling of one dimensional vertical and horizontal current flow (bias dependent) space charge and neutral regions

(b) by partial decoupling of the Poisson and drift/diffusion equations depending on the quasi neutrality conditions (this is performed by self consistent internal monitoring of electric field and space charge versus vertical and horizontal position during the numerical simulation).

Technical considerations

Impurity profiles for the device may be supplied as multi quasi-gaussian functions or (for the Full Bipole3 software) as tabular data. Because the software is designed for specific devices (diodes, BJTs, HBTs, MOSFETs) . The input geometry is defined by mask templates for various mask layouts. Options include internally selected layout rules so that in the simplest case for initial designs, only a minimal number (typically four values) of mask dimensions need be specified, although for final designs a complete set of mask dimensions can be supplied as input.

Because of this feature, an important characteristic of Bipole3 for industrial and educational use is that the user time required for setting up a simulation is a small fraction of that frequently required when using a ‘conventional full 2D' simulator. Because of the large number of example files for devices which are included with the software package, it is usually possible for a new user to start with an existing file which describes a device similar to one for which a simulation is required, and then making suitable modifications to the mask dimensions and the impurity profiles. It thus takes a very short time to generate results for a particular new device.

For the integrated circuit bipolar transistor, BIPOLE3 includes the following third dimension effects: base and collector resistances (with identification of separate components), total junction capacitances with separate identification of plane and sidewall capacitances for the e-b, b-c and c-s junctions.

Detailed comparisons have been made between BIPOLE3 simulation results and experimental results from high performance industrial BJTs with 20 GHz ft values and with SiGe HBTs having ft values in excess of 100 GHz. Comparisons are routinely made of measured versus simulated dc gain versus Ic and Vce , Ic and Ib Gummel plots versus Vbe, ft versus Ic. 1D and 2D comparisons are also made with other industrial and university software packages using full Poisson/transport equation solutions. Agreement is excellent for typical high performance devices. In particular for BJTs and HBTs the plots of transition frequency ft versus collector current are in excellent agreement up to currents above those for peak ft.

Gummel-Poon SPICE 2G6 model parameter enhanced extraction (with the SPI Extension Module) has been widely used by industry in BIPOLE3 for many years; this includes graphic visualization simultaneously of BIPOLE3 and SPICE model generated plots; this provides both numerical and visual verification of the precision of the parameter extraction for the chosen bias ranges. Graphs include Ic and Ib Gummel plots, vs Ic, ft vs Ic, Rb vs Ic. All these are generated at two values of Vcb. Some examples of these and other significant plots are included in the Tutorial Guide.

An easy to use menu driven graphics post-processor package BIPGRAPH is an integral part of BIPOLE3. This enables the user to view or print results in seconds.

The MOSFET option, MOSCALC, has been considerably extended and is valid for non constant doping profiles in the vertical direction (e.g. due to channel implants)

The simplified but powerful simulation software Bipole3-Basic is now (September 2014) available FREE for direct download from this site. This is ideal for many graduate student research projects. It contains many of the features of the full Bipole3 package (such as mask layouts for integrated BJTs, and including SiGe HBT structures with various Ge(x) distributions). The Bipole3-Basic Reference Manual and Tutorial Guide are included in the free download.

The Bipgraph graphics post-processor is included in teh free download.

Why use a fast bipolar device simulator?

The BIPOLE3 simulator is designed primarily for bipolar transistors (but also includes a fast MOSFET simulation option using similar numerical simulation algorithms which provides basic prototype study of MOSFETs). It is easy to use and executes in several seconds or less, with all significant 3rd dimension effects included and not available in most full 2D simulators (such as sidewall junction capacitance and sidewall injection, both of which contribute significantly to degradation of ft and fmax). This means that in an engineering design environment, input parameters can be altered and results obtained visually and superimposed to answer "What if" questions in several seconds of real time on modern PC computers. The design engineer can thus get a realistic feel for the significance of changes in impurity profile or mask layout. The final design of a BJT can be achieved extremely rapidly using manual or computer controlled iterative techniques.

BIPOLE3 has been used extensively in 'multi-run' engineering environments for optimizing certain design parameters (e.g. using Response Surface Techniques for BVceo - ft design using an SIC layer). It is also ideal for sensitivity studies of impurity profile and mask layout on such electrical characteristics as gain and ft versus Ic. More recently we have coupled BIPOLE3 to a neural network, making thousands of BIPOLE3 runs to train the network to enable terminal d.c. and h.f. characteristics to be supplied as input, with impurity profile and mask layout as output. This has great potential for device design optimisation. Given the total number of runs, this type of study would be extremely difficult to perform using conventional general purpose semiconductor device simulators, which run typically one hundred times slower than BIPOLE3.

The Bipole3 input format for tabulated impurity profile doping distributions is such that output from process simulators or SIMS measured data can be readily converted to form the input data. Interfaces are available for specific cases.

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