Tunneling-assisted impact ionization fronts in semiconductors

Abstract

Rodin, P.; Ebert, U.M.; Hundsdorfer, W.; Grekhov, I.V. Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rightsCopyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. We discuss a type of ionization front in layered semiconductor structures. The propagation is due to the interplay of band-to-band tunneling and impact ionization. Our numerical simulations show that the front can be triggered when an extremely sharp voltage ramp (ϳ10 kV/ns) is applied in reverse direction to a Si p ϩ -n -n ϩ structure that is connected in series with an external load. The triggering occurs after a delay of 0.7 to 0.8 ns. The maximal electrical field at the front edge exceeds 10 6 V/cm. The front velocity v f is 40 times faster than the saturated drift velocity v s . The front passes through the n-base with a thickness of 100 m within approximately 30 ps, filling it with dense electron-hole plasma. This passage is accompanied by a voltage drop from 8 kV to a voltage in the order of 10 V. In this way a voltage pulse with a ramp up to 500 kV/ns can be applied to the load. The possibility to create a kilovolt pulse with such a voltage rise rate sets new frontiers in pulse power electronics.

Theory of superfast fronts of impact ionization in semiconductor structures

“…Numerical simulations show that in the presence of this ionization mechanism the character of front propagation substantially changes. 18 The respective fronts have been called tunneling-assisted impact ionization fronts. 18 Recently, the dynamic avalanche breakdown of high-voltage diodes with stationary breakdown voltage u b Ϸ 1.5 kV at extremely high voltage about 10 kV, which corresponds to electric fields above the threshold of Zener breakdown, has been observed experimentally.…”

“…18 The respective fronts have been called tunneling-assisted impact ionization fronts. 18 Recently, the dynamic avalanche breakdown of high-voltage diodes with stationary breakdown voltage u b Ϸ 1.5 kV at extremely high voltage about 10 kV, which corresponds to electric fields above the threshold of Zener breakdown, has been observed experimentally. 19 The analytical theory of tunnelingassisted impact ionization fronts will be reported separately.…”

“…Later on the focus mostly shifted from analytical studies to numerical simulations. [14][15][16] The demand for a quantitative analytical description remains strong, in particular, as ionization fronts in wideband materials 17 and also operation at electric fields above the band-to-band Zener breakdown 18,19 have a promising prospective. Analytical theory is also important to place ionization fronts in doped semiconductor structures into the general context of studies on front dynamics in spatially extended nonlinear systems.…”

Investigation of Charge Carriers Space Self–Organization in Strong Electrical Fields

“…Однако обоснование такого большого значения M вызывает большие со-мнения из−за малой толщины слоя умножения. Бы-ли попытки объяснить образование микроплазмы тунелированием носителей заряда, которые показа-ли, что сгенерированные носители создают лавину, становящуюся намного интенсивнее самого процесса тунелирования [3]. Это привело к созданию модели мультистримерного пробоя [4], которая впоследствии была подвергнута критике [5].…”

Nonlinear Terahertz Metamaterials via Field-Enhanced Carrier Dynamics in GaAs

“…Although we attribute the carrier multiplication primarily to IMI, Zener tunneling cannot, a priori, be discounted. Tunneling calculations [27] show that with an in-gap peak field of 2.8 MV/cm, Zener tunneling can generate a free carrier density of ∼ 10 17 /cm 3 which is one order of magnitude smaller than that reached by IMI. This indicates that carrier generation may involve both processes.…”