Unilfied electro-thermal stability criterion for bipolar transistors

Physics-based stability analysis of MOS transistors

“…Thermal failure can occur because of thermal runaway in each of the current components I dMOS ; I c or I ii . The temperature coefficient of I dMOS depends on V gs [17], I ii has a slightly-negative temperature coefficient [18] (not included in the model), and I c has a positive temperature coefficient [19]. In most cases, the increase in I c (also including thermal leakage) induced by self-heating determines thermal instability [2,3,5,8].…”

“…The condition (2) corresponds to the thermal runaway condition discussed in Section 3.2. However, in this case, the expression for the temperature coefficient / d is not given by (19), which only accounts for thermal phenomena, but by (28), which also accounts for the electrical feedback occurring at the base node of the bipolar. For this reason, it is natural to define the electro-thermal stability factor as (compare with (18)):…”

A 27GHz, 31dBm power amplifier in a 0.25μm SiGe:C BiCMOS technology

“…This reduces the minimum required metal track width for preventing electromigration. The devices are scaled such that both operate near peak G max current density and in their "safe operating area" (SOA) regarding electro-thermal breakdown [4]. This resulted in a HV-CB device with a 0.4x20.4x20μm emitter area, which is a factor 2.5 larger than the LV-CE emitter area (0.4x20.4x8μm).…”

Understanding Radiation- and Hot Carrier-Induced Damage Processes in SiGe HBTs Using Mixed-Mode Electrical Stress

“…In this manner, the number of carriers injected into the high CB electric field is very well controlled. Although this approach may seem a rather unlikely configuration, it eliminates the problem of thermal runaway, as in the case of a forced base-and collector-voltage configuration [8]. Another way to assess mixed-mode damage is called the mixed-mode current sweep, which will be described in a later section.…”