Mohamad Faris Mohamad Fathil
Thumbnail Image
Preferred name
Mohamad Faris Mohamad Fathil
Official Name
Mohamad Faris, Mohamad Fathil
Alternative Name
Fathil, Mohamad Faris Mohamad
Fathil, Mohamad Faris Bin Mohamad
Main Affiliation
Scopus Author ID
56395434600
Researcher ID
U-3213-2019

Research Output
Now showing 1 - 3 of 3
Thumbnail Image
Publication

Polysilicon nanowire with liquid gate control for pH sensing

2018-12 , Mohammad Nuzaihan Md Nor , M. F. Farizal , C. W. Chung , M. N. Aziz , Mohamad Faris Mohamad Fathil , C. Ibau , S. Johari , Mohd Khairuddin Md Arshad

Polysilicon nanowire based sensors have garnered great potential in serving as highly sensitive, label-free and real-time sensing for broad range of applications, that include but not limited to pH values, DNA molecules, proteins and single viruses. In this research, two distinct types of polysilicon nanowires are fabricated, one has an array of nanowires with a 100 nm width and the other is a single nanowire with 100 nm width. Top-down fabrication method is utilized to fabricate the polysilicon nanowire from silicon wafer using the conventional photolithography and reactive ion etching processes. The fabricated polysilicon nanowire have an approximately 100 nm in width, is then undergo surface modification, which is the nanowire is immersed into a 2% 3-aminopropyltriethoxysilane (APTES) to create a molecular binding chemistry, which results in amino (NH2) and silanol (SiOH) groups at the nanowire surface. Since the surface of the polysilicon is hole-dominated (p-type material), it responds well to changes in pH values. In this research, pH sensing is performed based on several types of standard aqueous pH buffer solutions (pH 2, pH 4, pH 7, pH 10 and pH 12) to demonstrate the electrical response of the sensor. At low pH, NH2 group is protonated, resulting in high proton ion acts as a positive gate. At high pH, SiOH group is deprotonated, resulting in bringing negative charges at the polysilicon nanowire surface and acts as a negative gate voltage. The sensitivity of the polysilicon nanowire attained was 207.1 fS/pH for array nanowire and 8.91 fS/pH for single nanowire, which shows excellent properties for pH sensing.

View
Thumbnail Image
Publication

ESD improvement in P-i-N diode through introducing a lighter and deeper anode junction

2017-07 , J. H. See , Mohd Khairuddin Md Arshad , Mohamad Faris Mohamad Fathil

Continuous and aggressive miniaturization in the electronic gadget size poses a challenge in solving Electrostatic Discharge (ESD) reliability performance. For diode devices, the shrinkage of the size leads to severe electrical field crowding effect which can cause a total device failure under high ESD surge. Therefore, in this paper, we present a better ESD performance characteristic which can be achieved by optimizing the profile of the P+ anode junction of P-i-N diode. The characteristics profile can be altered by lowering the dopant concentration and increasing the depth of the P-i-N diode junction. In this work, comprehensive device simulations, followed by simulation result validation at the wafer level were performed. The ESD surge test was performed and results showed that the changes of the P+ anode junction profile on the P-i-N power switching diode can achieve the sustainability of 1 kV ESD surge in the Human Body Model (HBM) and more than 400 V ESD surge in the Machine Model (MM).

View
Thumbnail Image
Publication

FET with underlap structure for biosensing applications

2018-01 , Claris C. J. W , Mohd Khairuddin Md Arshad , C. Ibau , Ramzan Mat Ayub , Mohamad Faris Mohamad Fathil , Norhaimi W. M. W.

This paper presents the numerical simulation of an underlap field effect transistor (FET) device architecture on silicon‐on‐insulator (SOI) substrate for biosensing applications. By using the Silvaco ATLAS device simulator, this work is aimed to elucidate the effects of the different gate lengths, the presence of interface charge on the underlap sensing region, and also the effects of different gate biases (i.e. singlegate biasing, synchronous doublegate biasing and asynchronous doublegate biasing) on the magnitude of drain current (ID) of the simulated device. It is found that shorter gate length with the positive charges (on the n‐p‐n structure), at the sensing channel area increased the electron concentration at the channel and substrate/buried oxide interface. In asynchronous doublegate with a +3V of back‐gate supply and synchronous double‐gate, both increased the ID at different magnitude level and off‐current. Thus, depending on the biomolecule charges, the substrate biasing can be altered to improve the device’s sensitivity.

View