Quantitative Investigation of Laser Beam Modulation in Electrically Active Devices as Used in Laser Voltage Probing

Through silicon in-circuit logic analysis for localizing logic pattern failures

“…In short, a CW 1319 nm laser beam is directed to an active region in the IC through the backside. The reflected beam is modulated by the carriers in the transistor active region [9,10,22], separated in the return path, and routed to a fast photo-detector. In previous designs, the output of the detector is directed to either a digitizing oscilloscope or an analog spectrum analyzer.…”

“…Backside optical probing techniques were developed [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] and more recently improved with continuous wave (CW) laser timing probe [21] using wavelengths around 1300 nm. Furthermore, Frequency Mapping (FM) was added to CW laser timing probe to provide spatial information about the carrier modulation activity of the device [21][22][23][24][25]. While CW laser timing techniques have significantly improved the acquisition times and ease of use, there are still limitations: (1) The digitizing oscilloscopes used to process the laser timing signals have high latency mainly due to processing the large number of digitized samples internally.…”

Physical IC debug – backside approach and nanoscale challenge

“…Originally, the signal has been attributed to electrical fields in the device due to free carrier dynamics (Franz-Keldysh-Effect). Recent investigations using device simulation succeeded to correlate the signal to the dynamics of absorption and refractive index due to the presence or absence of free carriers by space charge modulation (Kindereit et al 2007), which allow simpler modeling of the effect (see Fig. 4 and 5).…”

The device characteristics of missing LDD implantation via nanoprobing techniques for localized failure analysis

“…The mechanism of PVC [6] stems from the forward and reversed behaviors of P/N junction and related with capacitance effect. Other optical based electrical analysis techniques were then introduced for fault isolation such as photon emission microscope (PEM), OBIRCH/TIVA/OBIC/LIVA in Static Laser Stimulations (SLS), SDL [2] and LADA [3] in Dynamic Laser Stimulation (DLS), Laser Voltage Probing (LVP) [4] and Laser Voltage Imaging (LVI) [5] at the circuit or product level. Furthermore, conductive atomic force microscopy (C-AFM) provides the additional capability of current mapping and locally current-voltage measurement at the contact-level [7].…”