Indian Institute of Science

Milova Paul

Harald Gossner

Mayank Shrivastava

Christian Cornelius Russ

B Sampath Kumar

The present disclosure relates to a Dual Fin SCR device having two parallel fins on which cathode, anode, n- and p-type triggering taps are selectively doped, wherein one Fin (or group of parallel Fins) comprises anode and n-tap, and other Fin (or group of parallel Fins) comprises cathode and p-tap. As key regions of the proposed SCR (anode and cathode), which carry majority of current after triggering, are placed diagonally, they provide substantial benefit in terms of spreading current and dissipating heat. The proposed SCR ESD protection device helps obtain regenerative feedback between base-collector junctions of two back-to-back bipolar transistors, which enables the proposed SCR to shunt ESD current. The proposed SCR design enables lower trigger and holding voltage for efficient and robust ESD protection. The proposed SCR device/design helps offer a tunable trigger voltage and a holding voltage with highfailure threshold.

Dual fin silicon controlled rectifier (SCR) electrostatic discharge (ESD) protection device

SCRs are a must for ESD protection in low voltage&#x2014;high speed I/O as well as ESD protection of RF pads due to least parasitic loading and smallest foot print offered by SCRs. However, conventionally designed SCRs in FinFET and Nanowire technology suffer from very high turn-on and holding voltage. This issue becomes more severe in sub-14 nm non-planar technologies and cannot be handled by conventional approaches like diode- or transient-turn-on techniques. Proposed invention discloses SCR concept for FinFET and Nanowire technology with diffused junction profiles with sub-3V trigger and holding voltage for efficient and robust ESD protection. Besides low trigger and holding voltage, the proposed device offers a 3 times better ESD robustness per unit area.

FinFET SCR with SCR implant under anode and cathode junctions

The present disclosure relates to non-planar ESD protection devices. The present disclosure provides a device structure and method of fabricating the structure that is essentially immune to latch-up and possess high ESD robustness and reliability. In an aspect, the present disclosure provides a mixed silicidation and selective epitaxy (epi) FinFET processes for latch-up immunity together with ESD robustness, thereby allowing achievement of ESD efficient parasitic structures together with latch-up immune and reliable functional devices. The present disclosure provides a dual silicidation scheme where ESD protection element(s) have fins that are partially silicided, and functional devices have fins that are fully silicided. The present disclosure also provides a hybrid contact and junction profile scheme where ESD protection element(s) have fins that are partially silicided with or without deep junctions depending on their application, and functional devices have fins that are fully silicided with the silicide edge crossing the junction. On the other hand, a dual Epi scheme is implemented such that ESD protection elements have fins with Epi contact, and functional devices have fins that are fully silicided without Epi (raised S/D) contact.

Semiconductor devices and methods to enhance electrostatic discharge (ESD) robustness, latch-up, and hot carrier immunity

The present disclosure relates to a thermal management solution for ESD protection devices in advanced Fin- and/or Nanowire-based technology nodes, by employing localized nano heat sinks, which enable heat transport from local hot spots to surface of chip, which allows significant reduction in peak temperature for a given ESD current. In an aspect, the proposed semiconductor device can include at least one fin having a source and a drain disposed over a p-well or a n-well in a substrate; an electrically floating dummy metal gate disposed close to drain or hot spot over at least a portion of the at least one fin, and an electrical metal gate is disposed close to the source; and a nano-heat sink operatively coupled with the dummy metal gate and terminating at the surface of chip in which the semiconductor device is configured so as to enable transfer of heat received from the at least one fin through the dummy metal gate to the surface of the chip.

Non-planar electrostatic discharge (ESD) protection devices with nano heat sinks

The present disclosure relates to a Silicon Controlled Rectifier (SCR) in non-planar technology to provide a robust ESD protection in System on Chip employing non-planar technologies. The disclosed SCR incorporates wire or fin shaped nanostructures extending from p-type tap to cathode, from the cathode to anode, and from the anode to n-type tap to provide parallel trigger paths to prevent problem of current crowding at the base emitter junction that limits efficient turn-on in conventional SCRs. The proposed structure helps in offering lower trigger and holding voltage, and therefore very high failure currents. The disclosed SCR has sub-3V trigger and holding voltage to provide an efficient and robust ESD protection in SOCs. The proposed device also offers three times better ESD robustness per unit area. Further the proposed SCR has no added capacitive loading and is compatible with standard process flow and design rules.

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Bengaluru, India

Milova Paul