“…[16,32] the prenotch was machined straight down in the central part of the sample only, leaving two side walls that formed a precrack when bend-testing thin film samples of silicon oxide, nitride or oxynitride. Testing of small-scale beams containing FIB-premachined notches has been shown in several studies to give K c values near those found for macroscopic samples [15][16][17]26,27]; however, in many other studies, different results, ranging from values slightly to much higher [11,18,19,[21][22][23][24]30,33], or in some cases lower [20,34], than the toughness data from tests on macroscopic specimens of the same material were obtained with FIB-notched specimens.…”