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SUMMARY:Promotionsvortrag Physik: On-Chip Mechanics as a Contribution 
 to the 4H-SiC Technology Platform
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 00000010000000162F2A31C90BD443BF85C506E05FD0F2
DESCRIPTION:Ankündigung des Promotionsvortrags von: Herrn André Hoch
 reiter Silicon carbide&#8217\;s (SiC) combination of high-quality sing
 le-crystalline 4H-SiC wafers and its excep-tional mechanical propertie
 s form an outstanding set of possible applications. To fully leverage 
 these mechanical properties\, this thesis introduces a monolithic fabr
 ication strategy that forms the desired 3D-structures monolithically o
 ut of the single-crystal wafer. This approach diverges from traditiona
 l dry-etching methods by relying on a sophisticated electrochemical et
 ching (ECE) pro-cess. By leveraging ion-implanted doping contrasts\, t
 he ECE selectively removes p-SiC while pre-serving n-SiC\, resulting i
 n a free-standing\, essentially stress-free n-SiC layer for high-quali
 ty na-nomechanical resonators such as cantilevers\, bridges\, and memb
 ranes. A central contribution of this work is the precise adjustment o
 f 4H-SiC resonator properties achieved by applying controlled tensile 
 stress through a chip-bending method using the squeeza-ble nanojunctio
 n (SNJ) setup. We achieve a 2.6-fold increase in the first eigenfreque
 ncy (f1: 540 kHz to 1400 kHz) and a five-fold boost in the quality fac
 tor (Q) of a 110&#215\;10 μm bridge resonator under 228 MPa of applie
 d stress. This research validates the Euler-Bernoulli beam (EBB) model
 \, using experimental laser Doppler vibrometer (LDV) measurements of t
 he first eigenfrequency\, against COMSOL simulations. To further valid
 ate the SNJ setup performance\, chip-bending sim-ulations (COMSOL) are
  compared against white light interferometry measurements. Overall\, e
 xperimental and theoretical results align within 13% across all metric
 s: mechanical de-formation\, eigenfrequency\, and tensile stress &#821
 1\; the latter calculated via the EBB model using LDV-measured f1 data
 . These results establish the SNJ method as a fully reversible post-fa
 brication degree of freedom that decouples device performance from fab
 rication precision. By enabling the dynamic adjustment 
DTSTART:20260506T130000Z
DTEND:20260506T143000Z
LOCATION:Hörsaal F\, Biologikum-Hörsaalgebäude\, Staudtstr. 5\, Erlangen
DTSTAMP:20260501T060358Z
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