Isha Yadav

Defence Research and Development Organisation | DRDO · Solid State Physics Laboratory (SSPL)

Aluminum nitride (AlN) and silicon carbide (SiC) are the two most prominent materials to extend the application potential of micro-electro-mechanical system (MEMS) based sensors to high temperature and harsh environment. Among different technical challenges, the evaluation and control of the growth induced residual stress in the AlN/ SiC MEMS devic...

MEMS based inertial switches have important applications in defense, automobile, and aviation sectors. The materials for these inertial switches are either metals or low-resistivity silicon. This paper discussed about the amalgamation of metal and silicon in the MEMS inertial switch (500 g) structure to achieve high performance and high current han...

This paper presents etching optimization of comb structure formation in small silicon substrates mounted on a large silicon wafer (150 mm diameter) using the S1818 photoresist adhesive layer. A series of deep reactive ion etching (DRIE) experiments are done by varying the etching conditions and tweaking the baking schedule of the photoresist adhesi...

In this review, we have comprehensively elaborated on the various materials suitable for the infrared (IR) bolometer applications and also provided the underlying mechanisms of various reported device structures. IR bolometers are used for thermal imaging, operates by changing the resistance of the sensing layer upon absorbing the IR radiation from...

This paper presents the feasibility of non-stoichiometric TiOx thin films as an active material for bolometer application. The TiOx films have been deposited on glass substrate by DC sputtering with oxygen flow rate of 0.1–0.7 sccm at room temperature and their electrical properties have been studied. The TiOx films were found to be amorphous with...

This paper discusses about the fabrication of comb-structure with vertical sidewall profile by wet chemical etching of Si (110) substrate in boiling KOH solution. Etch rate of the Si (110) substrate in boiling KOH solution is 9 times higher with a 40X reduction of average surface roughness than the etch rate at 75 °C. An etch selectivity of 48:1 fo...

This paper discusses the design and fabrication of MEMS differential capacitive accelerometer (z-axis sensitive) structure. The accelerometer structure consists of one each movable and reference capacitors in the single accelerometer die fabricated using highly conductive (p-type, resistivity: 0.001 Ω cm) SOI substrate. Resonant frequencies of the...

MEMS based accelerometers have already penetrated defense programs including navigation control in addition to their usual deployment in automotive, consumer and industrial markets because of their improved reliability, accuracy and excellent price performance. This paper discussed about the fabrication and testing of single axis capacitive acceler...

Benzocyclobutene (BCB) is widely used for wafer level packaging of radio frequency micro-electro-mechanical system (RF MEMS) devices. Although BCB is spin-coated at room temperature, its prebaking, post baking and subsequent processing may induce residual stresses. This work intends to investigate the stress–temperature behaviour of BCB films. In t...

RF MEMS devices like switches are made up of movable fragile structures that need to be encapsulated in microcavities to protect them from contamination or damage during the subsequent wafer dicing and packaging process steps. This packaging method is referred to as wafer-level or zero- level packaging and enables the whole MEMS wafer to be package...

Positive photoresists are invariably used as sacrificial layers for fabricating surface micromachining based MEMS devices. The stresses induced in photoresist films can cause cracking leading to eventual device failure. In this paper, the variation in stress of photoresist films with baking temperature and its correlation with thickness of the PR f...

Dissolved wafer process (DWP) is being extensively used to fabricate complex micro-electro-mechanical system (MEMS) structures. Etching non-uniformity, increased surface roughness and duration of DWP is often influence MEMS devices yields. This paper presents a modified DWP involving lapping and polishing followed by chemical etching of silicon to...

Electroplated gold is widely used as the material for the micromachined beam structures due to its excellent electrical and mechanical properties. This work attempts to analyze the surface micromachined gold cantilever beams under inherently present stress gradient. The structure is analyzed by using finite element method simulation at different in...

Microfabrication technology, more commonly applied to the manufacture of integrated circuits, can be used to build devices useful for mechanical delivery of drugs and genes. Microprobes fabricated using silicon micromachining have been used to deliver DNA into cells as an alternative to bombardment and microinjection. This idea can be extended to i...

Ultrathin (<50 nm) zirconium oxide (ZrO2) films are being intensively studied as high-k dielectrics for future metal-oxide-semiconductor (MOS) technology. In this paper, ultrathin ZrO2 films are deposited on silicon substrates by spin on deposition technique and annealed at 700 !C for different duration. The phase formation and morphological study...