Temperature-dependent Lowering of Coercive Field in 300 nm Sputtered Ferroelectric Al_0.70Sc_0.30N

High-Temperature Ferroelectric Behavior of Al0.7Sc0.3N

“…The (0002) reflection appeared at 36.056° in 2θ with a full width at half maximum (FWHM) value of 0.158°. The ω−rocking scan of the (0002) position resulted in an FWHM value of 2.694°, which is comparable to prior reports (Figure 2b) [16,22]. Lack of additional wurtzite peaks associated with other orientations indicates that the film had a purely c−axis texture.…”

“…of (c) ∆Ec/2 and (d) Pr results from this work with Mizutani et al [21], Zhu et al [20], Gund et al [22], and Wang et al [20]. The results in (a,b) are from this work, while (c,d) are a comparison of our results with previous reports.…”

“…The overall Ec results (apart from the reduced Ec values reported by Wang et al) are consistent with the literature in terms of a lower Ec due to increasing Sc content or decreasing excitation frequency. This may explain both the coincidental values between Gund et al (30% Sc, 3 kHz) and Zhu et al (16% Sc, 333 Hz) and the increased Ec for Mizutani et al (20% Sc, 100 kHz) [19][20][21][22]. Our work shows that the Pr values for Al0.7Sc0.3N remained relatively stable up to 400 °C (Figure 3d).…”

“…The increasing leakage with temperature is important for compensation when possibly measuring changes in polarization (e.g., during retention testing). [19][20][21][22]. Our work shows that the P r values for Al 0.7 Sc 0.3 N remained relatively stable up to 400 • C (Figure 3d).…”

“…While this high E c is problematic for integration with low−voltage devices, it can be valuable for retention characteristics as temperatures increase [8]. The E c of AlScN can be tuned through various modifications such as composition [14][15][16], stress [17], epitaxial alignment [18], and temperature [19][20][21][22]. In addition to thickness scaling, these trends are important for integrating AlScN into a high−temperature chip to reduce the operating voltages.…”