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Current flow lines (a) and equivalent circuits (b) for an un-trigged AS-MCT. In (a), only the half-cell is plotted. The OFF-FET structure is omitted.
Source publication
The MOS-controlled Thyristor (MCT) has been characterized by MOS-gating, high current rise rate, and high blocking capability. The anode short MCT (AS-MCT) is distinguished from conventional MCT by an anode-short structure, which develops a normally-off characteristic. As a composite structure made of metal-oxide-silicon and bipolar junction transi...
Contexts in source publication
Context 1
... of PNP is also shorted by such a structure, and then, α PNP is suppressed which is nearly zero for the case of small anode current. Under such conditions, the AS-MCTs are operated in blocking mode, and the upper NPN with wide collector region (N-base) is capable of supporting the high voltage. Table 1 lists the symbols and parameters for AS-MCTs. Fig. 3 illustrates the current flow lines in AS-MCTs. When a positive gate bias is applied, the ON-FET is gradually turned on, and the electrons flow from the N + -well into the N-base region. Then these electrons flow through the Nbase region. These electrons are by-passed and collected by the anode-short structure. The electron current will ...
Citations
The insulated-gate bipolar transistor (IGBT) is characterized by metal-oxide-silicon (MOS)-gating, high current density, and high blocking capabilities. The trench field-stop reverse-conducting IGBT (TFR-IGBT) is distinguished from conventional IGBT (CON-IGBT) by trench MOS gate, field-stop layer, and collector-short structure. As a composite structure made of MOS and bipolar junction transistors (BJTs), TFR-IGBT is susceptible to displacement damage (DD). This work reports the DD effects on TFR-IGBT with the fast neutron fluence up to a fluence of 10
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">13</sup>
cm
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup>
. The transfer, forward conductive, and forward blocking characteristics are degraded subsequent to neutron exposures. The suppression of the hump current in the transfer curve is observed by neutron-induced damage. This article proposes, from a device physics perspective, the mechanism behind the characteristics degradation from DD in TFR-IGBT. The dependencies of the key parameters on neutron fluence are analytically modeled. Our models provide a good fit to the experimental data of the IGP20N65H5 TFR-IGBT subjected to fission neutrons.
The anode-short metal–oxide–silicon (MOS)-controlled thyristor (AS-MCT) is the latest generation of MCT. Due to its MOS gating, high-current-rise rate, normally-OFF, and high blocking capabilities, the AS-MCT is an ideal switch for pulse discharge application. Previously, we show that the static behaviors of AS-MCT are susceptible to displacement damage (DD) as it contains bipolar structures. As a continuation of our previous work, this article reports the experimental results for the degradation of pulse discharge circuit (PDC) characteristics induced by the DD of its XND1 AS-MCT switch following fast neutron exposure up to
$7.8\times {10}^{13}\,\,{\text {cm}}^{-2}$
. Both the charging time and the peak surge current of the PDC decrease significantly once the neutron flux surpasses a critical value,
$\sim {10}^{12}\,\,{\text {cm}}^{-2}$
. From device and circuit physics perspectives, an analytical model based on equivalent leakage current resistance is proposed to describe the degradation of the two parameters, and then, this article suggests the mechanisms behind such degradations from the neutron exposure of AS-MCT switch.
In this letter, a novel cut-off degradation of output current induced by high fluence neutron radiation is investigated for high-voltage silicon-on-insulator lateral double-diffused MOSFET (HV SOI LDMOS). Unlike low/middle fluence, severe current collapse occurs at low drain voltage. Combining experiments and energy band analysis, we reveal that a secondary charge removal effect leads to cut-off degradation, which is closely related to the field enhancement and high-density defects at high neutron fluence. Although the gate channel can be turned on after radiation, below drain threshold voltage (
$\text{V}_{\text {DT}}$
), electron drift is blocked by a potential barrier caused by the local space charge region with low trap occupation rate, rather than the global impact at low fluence. In addition, the influences of structural parameters on the cut-off degradation and
$\text{V}_{\text {DT}}$
are studied to guide the rad-hardening design of HV SOI LDMOS.
