A temperature dependent study of the tunnelling
characteristics in ZMR-SOI polysilicon
emitter transistor

Onno W. Purbo

Inter University Center in Microelectronics
Institute of Technology Bandung
Bandung 40132
INDONESIA
Tel: 62-22-250-1895
FAX: 62-22-438-338
Email: yc1dav@itbgtw.itb.ac.id

ABSTRACT

		A study of the temperature dependent (250K-350K) of the tunnelling parameters, namely, interfacial oxide thickness δ, hole χh and electron barrier height χe, at poly-mono Silicon interface in both ZMR-SOI and bulk-Silicon polysilicon emitter bipolar transistor (PET) is reported. Method to extract the tunnelling parameters from dc electrical measurements is described. It is found that for HF-dip etched PETs, χh and χe are about 1.1eV and 0.3eV, respectively. The extracted δ for bulk-Si PETs (about 5.5A) is consistently lower than that of the ZMR-SOI PETs (about 6.4A). The thicker δ in ZMR-SOI PETs may be due to the more defect density in the ZMR-SOI material. The tunnelling parameters, δ, χh and χe, are found to be weakly temperature dependent and justified through comparison between Bipole simulation and measured data. Furthermore, a parabolic interfacial oxide band seems to give a better fit for different temperatures.

1.	INTRODUCTION
	The use of polysilicon emitter bipolar transistor (PET) leads to self-aligned structures and, thus, a dramatic improvement of high frequency performance in light of the reduced parasitics which leads to its use in high performance integrated circuits [1]. An enhanced current gain due to base current reduction is observed in PETs. RCA cleaning just prior to the undoped polysilicon deposition during the PET's fabrication leaves a relatively thick interfacial oxide at the poly-mono emitter interface. In RCA cleaned PETs, a tunnelling mechanism is responsible for the base current reduction [2][3][4][5][6]. However, for PET's which received an HF-dip prior to the polysilicon deposition, thus, without deliberately growing an interfacial oxide, a variety of transport mechanisms have been postulated, which include thermionic-diffusion mechanisms [7] and reduced hole mobilities and lifetime in the polysilicon [8]. Others [9][10] use surface recombination velocity to accommodate several possible mechanisms simultaneously occurring in the emitter. The integration of different carrier transport models into a unified carrier transport model has been attempted [11][13]. However, in the recent reports [15][31], it was concluded that tunnelling is a plausible, dominating mechanism for the carrier transport even in HF-dip etched PETs. Comprehensive reviews of these mechanisms can be found in [14][31].
	In this work, attempts to study the tunnelling characteristics of our ZMR-SOI and bulk-Si PETs [16] at different temperatures (250K-350K) will be reported and compared. We extended our recently proposed method [17] to extract the tunnelling parameters, namely, interfacial oxide thickness δ, hole barrier heightχh and electron barrier heightχe, incorporating temperature dependent models.
	The extraction of δ and χh uses the measured Gummel plot data [17]. To extract χe from the measured data, it is required to know the emitter resistance Re and δ. For δ less than 7A, it is appropriate to assume a constant tunnelling dominated Re up to high current levels (Vbe around 1.5 Volt) [2]. However, for δ thicker than 15A, Re will no longer be constant in the high current region [2]. Thus, for HF-dip etched PETs for which δ is typically in the range of 5-11A [3][15], high current measurements such as the Ning-Tang method [24], which assumes a constant Re, can be used to extract the tunnelling dominated Re. To some extends, this method can be applied, with a larger error for RCA cleaned PETs, for which δ is typically in the range of 12-16A [2][3] provided that the emitter current crowding and other high level effects are avoided [25].
	A comparison of the extracted χh and δ using the earlier tunnelling models, namely, those due to DeGraff-DeGroot [4] and Ashburn-Soerowirdjo [3], will also be performed. Eltoukhy-Roulston [12] and Yu-Ricco-Dutton [11] models have employed more accurate physical phenomena, which incorporate Fermi-Dirac statistics for the carriers; as well, carrier transport and recombination mechanisms in the polysilicon region are taken into account, for fast bipolar numerical analysis. However, for the purpose of parameter extraction from experimental measurements, the Eltoukhy-Roulston [12] and Yu-Ricco-Dutton [11] models are somewhat less suitable. Allowing a smaller degree of accuracy, we adopt the Ashburn-Soerowirdjo model [3] which is basically similar to the Eltoukhy-Roulston model [12], but takes more series expansion terms into account than does the DeGraff-DeGroot model [4]. Since band bending at the oxide interface is negligible [3][19] due to the presence of heavy doping, we have neglected it in the DeGraff-DeGroot model used in our comparisons. Since both in the DeGraff-DeGroot [4] and Ashburn-Soerowirdjo [3] models the electron current is injected into the base via a carrier diffusion model, no comparison will be carried out for the extraction of χe.
	It is found that for our HF-dip etched ZMR-SOI and bulk-Si PETs, χh and χe are about 1.1eV and 0.3eV, respectively. Moreover, the extracted χh, χe and δ are found to be weakly temperature dependent. In  ZMR-SOI PETs, δ is found to be slightly thicker (about 1A thicker) than that for bulk-Si PETs, which might still be significant enough to explain the higher Re and higher current gain found in ZMR-SOI PETs [16]. From the extraction of χh(T) and χe(T), it is found that the assumption of a parabolic interfacial oxide band gives rise to a less sensitive temperature variation, in agreement with the experimental data and provides a link between the interfacial barrier and the impurity pile-up theory [18].
	This paper is organized as follows. In the second section, the theoretical background of the method to extract the tunnelling parameters will be described. Subsequently, the experimental set-up used to measure the PETs will be briefly described. In section four, the extraction results will be discussed. The discussions will consist of some background results on the temperature dependence of the parasitic resistances; the extraction of the extraction of tunnelling parameters and a comparison with simulation results. In the final section, we summarize on conclusions.

2.	THEORY
	In this section, the detailed method for extracting the tunnelling parameters at the poly-mono Silicon interface in the emitter of PETs will be described. Some of the major assumptions used to derive the model are as follow:

 1.	The thin interfacial oxide is characterized by a layer with uniform thickness δ.
 2.	Carrier transport at the emitter is dominated by a tunnelling mechanism through the thin interfacial oxide.
 3.	Uniformly doped polysilicon layer.
 4.	Interface states are neglected.
 5.	A constant tunnelling dominated Re at high current conditions is assumed for the HF-dip etched polysilicon emitter [2].
 6.	The voltage drop across the thin oxide interface (Vo) at low currents is negligible.
 7.	Assume negligible band bending at the oxide interface in the highly doped emitter [3][19].
 8.	No high level effects, such as, high level injection are present.

We use npn transistors for the discussion. Several temperature dependent physical properties have been incorporated to evaluate the extracted tunnelling parameters at different temperatures, namely, temperature dependent effective carrier masses [20] and the temperature dependent intrinsic carrier concentration nio [21] as well as band-gap narrowing (BGN) in the highly doped semiconductor [22].
	The tunnelling hole minority carrier current IpT, in which the time-independent tunnelling probability Pp(Ex) for holes given by the WKB approximation [23] is incorporated and can be written as [4][5],
											(1)
where fp1 and fp2 are the Fermi-Dirac distribution functions for holes in region 1 (polysilicon) and region 2 (Silicon), respectively; Ex is the energy component of the incident carrier in the x direction; Ae is the area of the emitter; mp* is the effective hole mass. Similarly, the electron majority carrier current InT which tunnels through the interfacial oxide with a probability Pe(Ex) can be represented as

											(2)
where fe1 and fe2 are the Fermi-Dirac distribution functions for electron in region 1 (polysilicon) and 2 (Silicon), respectively; me* is the effective electron mass.
	For a rectangular band structure assumed for the interfacial oxide layer, and a tunnelling probability Pp(Ex) that is weakly dependent on the energy Ex, the minority-carrier, tunnelling-dominated, base current Ib (Eqn. (1)) can be evaluated [17]

				(3)
where Vbe is the emitter-base voltage; nie is the effective intrinsic carrier concentration taking into account the temperature dependent intrinsic carrier concentration nio [21]; NdE is the temperature dependent effective emitter doping concentration [22]; k is the Boltzmann constant in eV T-1. 	To account for a possible non-rectangular band in the thin interfacial oxide, which may be responsible for the deviation in the temperature dependent behaviour of Re [18], an analytical expression for the tunnelling dominated Ib and a parabolic band has been developed as follows [17]

			(4)
As the parabolicity of the band C becomes closer to unity (rectangular interfacial oxide bands), Eqn. (4) reduces to Eqn. (3). The χh in Eqn. (4) represents the peak hole barrier height in the thin interfacial oxide. A Chi-Square fitting method is employed to fit the model (Eqn. (3) or (4)) to the measured Ib and, thus, to extract χh and δ [17].
	In highly doped regions, the quasi-Fermi level of the majority carrier is normally quite close to, or even merged into the respective majority carrier band and is hardly affected by the applied potential compared to the quasi-Fermi potential for the minority carrier. Taking into account the more rigid quasi-Fermi potential for majority carriers and using Fermi-Dirac statistics for the majority carriers in Eqn. (2) with NdE over the density of states of the conduction band, the majority electron tunnelling current in high performance PETs should be fairly close to the collector current Ic such that,

		(5)
Similarly for a parabolic band structure, the majority electron tunnelling current can be written as

	(6)
	The small voltage drop Vo across the thin interfacial oxide can be written as
						(7)
where Ico is the collector saturation current. Since Eqn. (5) and (6) are derived for low current conditions and, unfortunately, below the detection limit of the HP4145A Semiconductor Parameter Analyzer, it is difficult if not impossible to measure Vo from Eqn. (7) at low current.
	Assuming a negligibly small Vo across the thin interfacial oxide and a negligible voltage drop in the highly doped emitter region, the tunnelling dominated Re due to a rectangular band oxide at the interface, can be derived from Eqn. (5) as

					(8)
Similarly for a parabolic band oxide at the interface, Re can be determined from Eqn. (6) as follows

			(9)
In this work, Re is extracted by using an extended Ning-Tang approach [26] which employs Singular Value Decomposition and Chi-Square Fitting techniques to extract Re and to separate Rbx and Rbi(Vbe). Having determined Re [26] and knowing δ from the Chi-Square fitting of the measured Ib from the model given by Eqns. (3) and (4), χe can be obtained by evaluating the tunnelling dominated Re in Eqns. (8) and (9).

3.	EXPERIMENTAL SET-UP
	We use our 7X7 μm2 emitter single poly-emitter double base-contacts bipolar transistors [16] to demonstrate the applicability of the method. Both ZMR-SOI and bulk-Si PETs were prepared using identical and simultaneous processing subsequent to the formation of buried collector and epitaxial layers [16]. Since drive-in processes were performed at the final stages at 900oC, we assume no oxide break-up [27][28] and, thus, the transport mechanism across the thin interfacial oxide governs the carrier transport across the emitter [13][29]. We performed the extraction on both bulk-Si and ZMR-SOI PETs.
	An HP4145A Semiconductor Parameter Analyzer tied with a MMR Technologies Low Temperature Micro Probe (LTMP) is used to perform the dc measurements at the temperatures 250 to 350K. In this experiment, Gummel plot data with 2 millivolt Vbe intervals were collected. To ensure a reverse biased Collector-Base junction, a small reverse Collector voltage (around 1 Volt) was applied during Gummel plot measurements.

4.	RESULTS AND DISCUSSIONS
4.1.	Extraction of the Parasitic Resistances.
	The extraction of Re is required to obtain the tunnelling parameters, particularly χe. Employing the extended Ning-Tang method [26], Re, Rbx and Rbi(Vbe) as a function of temperature (250-350K) are extracted from the measured Gummel plot data. In this section, the results from the extraction of Re as a function of temperature is described.
	In Fig. [F1], the measured Re as a function of temperature is shown. Consistent with previous results [16], ZMR-SOI PETs have higher Re's compared to that for bulk-Si PETs, a difference which might be due to the existence of higher defect density in the starting ZMR-SOI [16]. The higher defect density may introduce a slightly thicker interfacial oxide thickness between the polysilicon and the mono-silicon emitter, which in turn renders the minority carrier injection from the base into the emitter and results in a lower Ib with a higher Re. 
	The measured Re's for both bulk-Si and ZMR-SOI PETs increase with a reduction in temperature. Due to the large defect density in the ZMR-SOI material, Arsenic in the emitter will diffuse faster in large area structures and thus, the resulting emitter sheet resistance will not reflect the actual temperature behaviour of Re. However, since more than 90% of the emitter depth consists of polysilicon, it is reasonable to assume that part of the Re(T) behaviour is coming from the polysilicon in the emitter. Figure [F2] shows the measured polysilicon sheet resistance as a function of temperature. It is interesting to note that the polysilicon sheet resistance has a very similar temperature behaviour to that observed for the extracted Re. The increase in the highly doped polysilicon sheet resistance at lower temperatures is due to the dominant impurity scattering process [23]. Considering the small area of the emitter 7x7μm2, a 2-4Ω/ difference (from 70Ω/) in the measured polysilicon sheet resistance between ZMR-SOI and bulk-Si should not make much different in Re. Thus, a large difference in the measured Re(T) (Fig. [F1]) between ZMR-SOI and bulk-Si PETs should be due to additional effects, such as tunnelling mechanisms [2].

4.2.	Extraction of Tunnelling Parameters.
	In this section, we examine the temperature behaviour and the difference in the tunnelling parameters between ZMR-SOI and bulk-Si PETs. In Fig. [F3], the extracted δ for temperatures between 250 and 350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols) PETs is shown. The results of δ(T) extraction from the measured Ib(Vbe,T) using a rectangular band in Eqn. (3) (), Ashburn-Soerowirdjo [3] (_) and  DeGraff-DeGroot [4] () models are presented. Using the parabolic band model (Eqn. (4), we obtained the exact behaviour of the extracted δ(T) for a rectangular band model is shown in Fig. [F3]. All models indicate that the extracted δ(T) is weakly temperature dependent. No significant differences are observed in the value of the extracted δ(T) among the different models used. Furthermore, ZMR-SOI PETs have typically thicker δ (about 0.8-1.0A) as compared with bulk-Si PETs, which might be due to an increased defect density in the ZMR-SOI material [32]. These results explain the higher dc current gain and Re in ZMR-SOI PETs compared to those for bulk-Si PETs.
	In Fig. [F4], the extracted χh for the rectangular band model (Eqn. (3)) at temperatures between 250 and 350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols) PET's is presented. The rectangular band (Eqn. (3)) (), Ashburn-Soerowirdjo [3] (_) and  DeGraff-DeGroot [4] () models are used to extract χh from the measured Ib(Vbe,T). The extracted χh obtained using the DeGraff-DeGroot model [4] is typically slightly lower than that of Ashburn-Soerowirdjo and Eqn. (3). The difference in the extracted χh among different models is fairly trivial which proves the accuracy of the model in Eqn. (3). The rectangular band χh at the interfacial oxide tends to decrease at lower temperatures, especially in bulk-Si PETs. The relative shift of the band in an insulator may be due to a temperature-dependent contraction which is similar to that found in semiconductors [30]. However, considering the high χh barrier, the relative shift in χh(T) is considered negligible. Furthermore, ZMR-SOI PETs seem to have a slightly lower χh compared with that for bulk-Si PETs. The lower χh in ZMR-SOI PETs may be due to the interfacial oxide in ZMR-SOI PETs which is more non-stoichiometric compared to the bulk-Si PETs material. The slightly lower χh in ZMR-SOI PETs does not affect the dc current gain and Re as much as the thicker interfacial oxide.
	The extracted χe for the rectangular band model (Eqn. (8)) at temperatures between 250 and 350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols) PETs is shown in Fig. [F5]. The extracted Re in Fig. [F1] is used to extract χe. A variation in the range of 0.03eV in the extracted χe(T) should be considered negligible to warrant a definite increase in χe(T) at lower temperatures (Fig. [F5]). Furthermore, ZMR-SOI PETs have typically a slightly lower χe compared to that for bulk-Si PETs, which might be related to the lower quality oxide on the higher defect density ZMR-SOI material [32].
	Figure [F6] shows the extracted peak χh () and peak χe (_) for both bulk-Si (solid symbols) and ZMR-SOI PETs (open symbols) as a function of the parabolicity of the oxide band at 300K. The extracted peak χh () and peak χe (_) typically increase as the oxide band structure becomes more parabolic (C closer to zero). This behaviour is consistent for both bulk-Si and ZMR-SOI PETs. The increase in the extracted peak χh () and peak χe (_) for parabolic oxide bands is necessary to overcome the increase in the tunnelling probability in parabolic band structure as compared to that for a rectangular band structure for the same peak barrier height. Furthermore, to accommodate a certain electron or hole current, the tunnelling probability for the parabolic and rectangular bands must be the same and, therefore, the peak barrier height for a parabolic band will be higher than that for a rectangular band as shown in Fig. [F6].
	To probe further, we investigate the variation of the extracted χe and χh as a function of temperature. The relative deviation of the average measured barrier height as a function of temperature is used as a figure as merit. We normalized the relative deviation to that of a rectangular barrier height. The normalized relative deviation of the average peak barrier height extracted for different temperatures (250 to 350K) is shown in Fig. [F7]. The relative deviation of χe and χh are shown as _'s and 's, respectively. The results for both bulk-Si (solid symbols) and ZMR-SOI (open symbols) PETs are shown. As shown in Fig. [F7], the normalized, relative deviation of the peak barrier height becomes much less than unity as the band becomes more parabolic (C closer to zero). The reduction of the relative deviations of χe and χh for a parabolic band is typically about 3-16% with respect to the relative deviation for rectangular band. The reduction for a the relative deviation in parabolic band indicates that the parabolic band model is more temperature independent than that of a rectangular band. Since the energy band gap is weakly dependent on temperature [30] and also the deviation in χe and χh, it is reasonable to conclude that the band shape of the interfacial oxide is more likely to be non-rectangular in agreement with Yung and Burk [18].

4.3.	Comparisons with Simulation Results.
	In this section, a comparison of the extracted results with the measured data will be performed. BIPOLE simulation software [12], which is capable of simulating accurately the behaviour of polysilicon emitter transistors, is used. SUPREM 3 generated doping profiles using exact processing steps as in Ref. [17] feeds into BIPOLE. In addition, the average of the tunnelling parameters for a rectangular oxide band from this experiment and the mask layout information is included in a BIPOLE input file and accounts for the more accurate calculation. The resulting simulated Gummel plot as well as Re for both bulk-Si and ZMR-SOI PET's will be presented and compared in this section.
	Figure [F8] shows the simulated Re(T), calculated using BIPOLE for both bulk-Si (solid symbols) and ZMR-SOI PETs (open symbols). Exact behaviour is observed in the simulated Re(T) (Fig. [F8]) and compared with the measured Re(T) (Fig. [F1]). Both measured and simulated Re(T) indicate an increase in Re at low temperatures. Furthermore, the thicker interfacial oxide thickness at the mono-poly silicon interface at the emitter has correctly accounted for the higher Re in the ZMR-SOI PETs (open symbols).
	In Fig. [F9], the BIPOLE simulated (dashed lines) as well as the measured (solid lines) Gummel plots for both bulk-Si (Fig. [F9]a) and ZMR-SOI PETs (Fig. [F9]b) at 300K is shown. In both bulk-Si and ZMR-SOI PETs, fairly good agreement is obtained between the measured Gummel (solid lines) plot and the BIPOLE simulated Gummel plot (dashed lines). Fairly good agreement between the measured and the BIPOLE simulated Gummel plots can be achieved in the temperature range between 250 and 350K. Thus, it can be concluded that the extracted χe, χh and δ from both bulk-Si and ZMR-SOI PETs are reasonably good and account properly for the tunnelling properties of PETs as a function of temperature (250 to 350K).

5.	SUMMARY
	In this paper, a method for extracting tunnelling parameters at the poly-mono Silicon interface, namely, χe, χh and δ, utilizing both rectangular and parabolic band models for the interfacial oxide region have been described and is used to analyze our bulk-Si and ZMR-SOI PETs at temperature 250K to 350K. The model used to extract χp and δ is similar to our earlier model [17]. For extracting χe, instead of directly using the expression for electron tunnelling, the Re extracted from the Ning-Tang method is used.
	It is found that the extracted results using our models are in a good agreement with previously published models, namely, those due to DeGraff-DeGroot [4] and Ashburn-Soerowirdjo [3]. A comparison between BIPOLE simulation software [12] and measured data indicates that the extracted χe, χh and δ are reasonable.
	It is found that for our HF-dip etch PETs the rectangular χh is about 1.1 eV and the χe is about 0.3 eV. Furthermore, it is found that the extracted χh and χe are weakly temperature dependent with possibly parabolic band structure. The ZMR-SOI PETs have typically thicker δ (about 0.8-1.0A) as compared with bulk-Si PETs. This is likely due to the higher defect density in the ZMR-SOI material.

6.	ACKNOWLEDGEMENTS
	The author would like to thank Prof.C.R.Selvakumar for his support in this project. The author wishes to thank the government of Indonesia and the Canadian International Development Agency (CIDA) for granting the overseas scholarship.

REFERENCES

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FIGURE CAPTION

Figure [F1].	The extracted emitter resistance Re(T) for temperature between 250K and 350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols) Polysilicon emitter transistors.

Figure [F2].	The measured polysilicon sheet resistance at different temperature for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols).

Figure [F3].	The extracted δ for temperature between 250K-350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols). Three different models, namely, rectangular band model (), Ashburn-Soerowirdjo [3] (_) and  DeGraff-DeGroot [4] () models are used.

Figure [F4].	The extracted χh for rectangular band model at temperature between 250K-350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols). Three different models, namely, rectangular band model (), Ashburn-Soerowirdjo [3] (_) and  DeGraff-DeGroot [4] () models are used.

Figure [F5].	The extracted χe for the rectangular band model at temperatures between 250 and 350K for both bulk-Silicon (solid symbols) and ZMR-SOI (open symbols).

Figure [F6].	The extracted peak χh () and peak χe (_) for both bulk-Si (solid symbols) and ZMR-SOI PETs (open symbols) as a function of the parabolicity of the oxide band at 300K.

Figure [F7].	The normalized relative deviation of the average peak barrier height extracted for different temperatures (250 to 350K). The relative deviation for a rectangular barrier height is used as a reference. The relative deviation of χe and χh are shown in _ and , respectively. The results for both bulk-Si (solid symbols) and ZMR-SOI (open symbols) PETs are shown.

Figure [F8].	The BIPOLE's simulated Re as a function of temperature for both bulk-Si (solid symbols) and ZMR-SOI PETs (open symbols). 

Figure [F9].	BIPOLE simulated (dashed lines) as well as the measured (solid lines) Gummel plot for both (a) bulk-Si and (b) ZMR-SOI PETs at 300K is shown.

Figure [F1].	The extracted emitter resistance Re(T) for temperature between 250K and 350K for both bulk-Silicon (solid blocks) and ZMR-SOI (blank blocks) Polysilicon emitter transistors.

Figure [F2].	The measured polysilicon sheet resistance at different temperature for both bulk-Silicon (solid blocks) and ZMR-SOI (blank blocks).

Figure [F3].	The extracted δ for temperature between 250K-350K for both bulk-Silicon (solid dots) and ZMR-SOI (blank dots). Three different models, namely, rectangular band model (), Ashburn-Soerowirdjo [3] (_) and  DeGraff-DeGroot [4] () models are used.

Figure [F4].	The extracted χh for rectangular band model at temperature between 250K-350K for both bulk-Silicon (solid dots) and ZMR-SOI (blank dots). Three different models, namely, rectangular band model (), Ashburn-Soerowirdjo [3] (_) and  DeGraff-DeGroot [4] () models are used.

Figure [F5].	The extracted χe for rectangular band model at temperature between 250K-350K for both bulk-Silicon (solid dots) and ZMR-SOI (blank dots).

Figure [F6].	The extracted peak χh () and peak χe (_) for both bulk-Si (solid symbols) and ZMR-SOI PETs (open symbols) as function of the parabolicity of the oxide band at 300K.

Figure [F7].	The normalized relative deviation of the average peak barrier height extracted for different temperatures (250K-350K). The relative deviation of rectangular barrier height is used as reference. The relative deviation of χe and χh are shown in _ and , respectively. The results for both bulk-Si (solid symbols) and ZMR-SOI (open symbols) PETs are shown.

Figure [F8].	The BIPOLE's simulated Re as function of temperature for both bulk-Si (solid symbols) and ZMR-SOI PETs (open symbols). 

Figure [F9].	BIPOLE simulated (dashed lines) as well as the measured (solid lines) Gummel plot for both (a) bulk-Si and (b) ZMR-SOI PETs at 300K is shown.