Gate-controlled silicon controlled rectifier with adjustable clamping voltage using a photoelectric mechanism

Area of Science:

• Semiconductor device physics
• Optoelectronics
• Integrated circuit design

Background:

• Silicon controlled rectifiers (SCRs) are widely used for voltage clamping.
• Controlling the voltage-clamping capability of SCRs flexibly is crucial for electrostatic discharge (ESD) protection.
• Existing methods often require structural modifications, limiting adaptability.

Purpose of the Study:

• To propose and analyze a novel photoelectric gate-controlled SCR (PGCSCR) for flexible voltage-clamping control.
• To investigate the impact of the photoelectric effect on the ESD characteristics of the PGCSCR.
• To demonstrate the tunability of the clamping voltage through optical stimulation.

Main Methods:

• Device design and fabrication using a standard 0.18 µm Bipolar CMOS DMOS (BCD) process.
• Analysis using equivalent circuits and Technology Computer-Aided Design (TCAD) simulations.
• Experimental verification using the ES620-50 Transmission Line Pulse (TLP) test system.

Main Results:

• The PGCSCR demonstrated a light-free clamping voltage of 4.308 V.
• Irradiation with 5 W/µm² at 450 nm reduced the clamping voltage to 3.655 V.
• Changing the wavelength to 600 nm further reduced the clamping voltage to 3.409 V.
• The observed changes are explained by the avalanche multiplication and photoelectric effects.

Conclusions:

• The PGCSCR enables flexible adjustment of clamping voltage without altering device structure or size.
• This tunability is achieved by leveraging the photoelectric effect and avalanche multiplication.
• The PGCSCR is a promising candidate for applications in integrated optical circuits, opto-coupling, and optical communication.