Low-Power, Antifuse-Based Silicon Chemical Sensor on a Suspended Membrane

Abstract

In this paper we describe a new, simple, and cheap silicon sensor operating at a high temperature of about 1000 K and consuming a very low power of a few milliwatts. We developed a silicon-processing compatible, simple, and low-cost method for processing thermally isolated suspended membranes. This makes the technology more compatible with standard complementary metal oxide semiconductor ͑CMOS͒ technology. The essential part of the device is a conductive link of several nanometers in size ͑the so-called antifuse͒ formed in between two polysilicon electrodes separated by a thin SiO 2 layer. An advantage of the proposed concept is decoupling ͑i.e., independent control͒ of the electrical and thermal resistances. The device can be utilized in chemical sensors or chemical microreactors requiring high temperature and very low power consumption, e.g., in portable battery-operated systems. As a direct application, we demonstrate a gas sensor ͑i.e., Pellistor͒ for hydrocarbons ͑butane, methane, propane, etc.͒ based on temperature changes due to the catalytic combustion of hydrocarbons. The power consumed by our device is about 2% of the power consumed by conventional Pellistors.

Nanolink-based thermal devices : integration of ALD tin thin films

“…where F is a function only of the ratio R r = R 12,34 /R 41,23 , satisfying the relation 4.532 ln (2) tR tR…”

“…Recently, a new generation of pellistor-type micro hotplate devices, socalled 'suspended membrane actuators' (SMAs), was reported by Kovalgin et al These thermal sensors and actuators have a power consumption of only a few milliwatts [1,2]. A schematic cross-section of the SMA is shown in Figure 1.2a.…”

“…Kovalgin et al showed that nanolink-based SMAs can be used as pellistors for the detection of hydrocarbons with a power consumption of only a few mW [2]. In Figure 1.2c, the (nano)link resistance is shown versus time during introduction of butane (C 4 H 10 ) pulses into the measurement chamber.…”

“…First of all, the positioning of the anti-fuse is not well defined as this is the result of the (statistical) SiO 2 breakdown process. Secondly, the initial electrical characteristics (R link , TCR) are poorly [2]. [2].…”

“…The design of the SMA is based on antifuse-based chemical sensors and actuators by Kovalgin et al [2], and consists of two crossing electrodes separated by an SiO 2 dielectric layer, as shown in …”