A Comprehensive Model for Plasma Damage Enhanced Transistor Reliability Degradation

A test circuit based on a ring oscillator array for statistical characterization of Plasma-Induced Damage

“…Plasma-Induced Damage (PID) has been an important concern for equipment vendors and fabs in both traditional SiO2 based and advanced high-k dielectric based processes [1][2][3][4][5][6]. Fig.…”

“…1 illustrates the PID phenomenon that occurs in a gate dielectric during the formation of a metal interconnect. The charge build-up in metal interconnects during the plasma processing steps introduces extra traps in the gate dielectric thereby worsening device reliability mechanisms such as Bias Temperature Instability (BTI) and Time Dependent Dielectric Breakdown (TDDB) [1][2][3]6]. The contiguous metal structure where the charge build up occurs is commonly referred to as an "antenna.…”

“…Unfortunately, circuit performance degradation is unavoidable even with the two methods for the following reasons: (1) previous studies have shown a noticeable difference in the PID-induced BTI lifetime for different ARs even within a given specification [3] or (2) inserted antenna diodes increase the capacitance of the metal interconnect, eventually making the circuit slower. To fully understand the impact of latent PID on device and circuit reliability, an efficient PID characterization method is needed.…”

“…(3) Rampedvoltage TDDB test was introduced in [1] to reduce the TDDB test time to 2 seconds per sample, but the main drawback is that the results do not match the standard TDDB results very well. (4) Measuring the remaining BTI lifetime has been generally accepted as the most effective method to detect latent PID, but only limited data have been reported so far as the unwanted BTI recovery [3] makes it difficult to collect high-quality BTI statistics.…”

“…2). Traditionally, characterization of PID-induced BTI degradation has involved continuously monitoring the transistor threshold voltage shift for a large population of devices using individual probing [3]. This method, however, is time-consuming and cumbersome due to serial stress.…”