What does 45nm soi mean

Several foundries are expanding their fab capacities for RF SOI processes amid huge demand and shortages of this technology for smartphones. RF SOI is a specialized process used to make select RF chips, such as switch devices and antenna tuners, for smartphones and other products. In simple terms, the number of frequency bands has increased in wireless networks.

In fact, demand is outstripping supply in the entire RF SOI supply chain, causing shortages on several fronts. Demand is accelerating. There is even an acceleration of this first generation 5G sub-6 GHz technology. In total, the industry is projected to ship 1. Around , that figure is projected to exceed 2 million wafers.

In total, Gartner forecasts that worldwide mobile phone shipments will reach 1. RF SOI chips are not the only devices used in phones. A smartphone consists of digital and RF chips. Based on CMOS, the digital part consists of the applications processor and other devices.

The front-end module consists of a number of components, including power amplifiers, antenna tuners, low-noise amplifiers LNAs , filters, and RF switches. The power amp provides the power for a signal to reach a destination.

LNAs amplify a small signal from the antenna, while filters prevent any unwanted signals from entering the system. LNAs and filters use various processes. RF switches route signals from one component to another, and tuners help the antenna adjust to any frequency band. Source: STMicroelectronics. For years, the RF content per phone has grown despite a slowdown in smartphones. In wireless systems, radio spectrum is divided into frequency bands. Several years ago, carriers deployed 2G and 3G wireless networks.

There were four frequency bands in 2G, and five for 3G. Recently, carriers have deployed a 4G wireless standard called LTE Advanced, which provides faster data rates in smartphones. It has also created band fragmentation in the cellular world. Many countries have allocated their own spectrum, so LTE now works across different frequencies in various nations. In addition, mobile operators have deployed a technology called carrier aggregation.

The growing number of bands, coupled with carrier aggregation, has impacted the RF market. First, the RF content per phone is increasing due to the sheer number of frequency bands. A diversity antenna boosts the downlink data rates in phones. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator or Login to access Optica Member Subscription. Allow All Cookies. Not Accessible Your library or personal account may give you access. Yang, F. Leo, A. Tauke-Pedretti, S. Arafin, M. Clerici, L. Caspani, L. Busse, M. Kats, J. Fan, W. Ming Steve Lee, D. Skip to search form Skip to main content You are currently offline. Some features of the site may not work correctly. DOI: Inac , M. Uzunkol , Gabriel M. Several transistor test cells are characterized and the effect of finger width, gate contact, and gate poly pitch on transistor performance is analyzed.

The measured transistor performance agrees well with… Expand. View on IEEE. Save to Library Save. Create Alert Alert. This process starts with the creation of the gate region followed by the creation of the drain and source regions using ion-implantation. The thin gate oxide under the gate acts as a mask for doping process preventing further doping under gate region channel. So, this process makes the gate self-aligned with respect to the source and drain. As a result of all this, the source and drain do not extend under the gate.

Thereby reducing C gd and C gs as shown in figure 2 b. Figure 2. If aluminum is used as a gate material, it would melt under such high temperature.

This is because the melting point of Al is approximately degree C. But, if polysilicon is used as a gate material, it would not melt. Thus, the self-alignment process is possible with polysilicon gate. While in the case of Al-gate, it is not possible, which results in high C gd and C gs. So, polysilicon is doped in such a way that its resistance is reduced. The other reason for selecting poly is that the threshold voltage of MOS transistor is correlated with the work function difference between the gate and the channel.

Earlier, metal gates were used when operating voltages were in the range of volts. But, as the transistors were scaled down, which ensured that the operating voltages of the device were also brought down.

A transistor with such high threshold voltage becomes non-operational under such conditions. Using metal as gate material resulted in high threshold voltage compared to polysilicon, since polysilicon would be of the same or similar composition as the bulk-Si channel. Also, as polysilicon is a semiconductor, its work function can be modulated by adjusting the level of doping.

For MOS transistor, the gate voltage determines whether a current flow between the drain and source will happen or not. When a sufficiently positive V gs voltage is applied to the gates of NMOS, the positive charges are placed over the gate as shown in figure These positive charges will repel the minority carriers of p-type substrate i.

If we increase Vgs further, at some potential level it will even make the surface attractive to electrons. So, plenty of electrons are attracted to the surface. This situation is called inversion because the surface of p-type body normally has a large number of holes but the newer surfaces have a large numbers of electrons. Drain-to-body and source-to-body are kept in reverse bias. Here in figure-3, source-to-body is kept at zero bias. As drain-to-body potential is more positive than source-to-body potential, the reverse bias across drain-to-body is larger resulting in deeper depletion under drain region compared to source side.

When positive potential across drain-to-source is applied, electrons flow from the source through the conducting channel and are drained by the drain. So, a positive current Id flows from drain-to-source. The demand for battery-operated portable gadgets have increased day by day with tons of applications including hearing aids, cellular phone, laptops etc.

For such portable devices, power dissipation is important because the power provided by the battery is rather limited. This is not sufficient to handle the increasing power needed in portable devices. In , Gordon E. By making transistors smaller, more circuits can be fabricated on the silicon wafer and therefore, the circuit becomes cheaper. The reduction in channel length enables faster switching operations since less time is needed for the current to flow from drain to source.

In other words, a smaller transistor leads to smaller capacitance. This causes a reduction in transistor delay. As dynamic power is proportional to capacitance, the power consumption also reduces. This reduction of transistor size is called scaling.

Each time a transistor is scaled, we say a new technology node has been introduced. The minimum channel length of transistor is called the technology node. For example, 0. The scaling improves cost, performance and power consumption with every new generation of technology. For long channel devices, the electric field lines are everywhere perpendicular to the surface of the channel. These electric fields are controlled by gate voltage and back gate voltage.

But, for short channel devices, the drain and source structure are closer to the channel, especially when the longitudinal electric field in the channel comes into picture. The longitudinal electric field is controlled by drain-source voltage. The longitudinal electric field is parallel to the current flow direction. The device is called short channel device if channel length is not much larger than the sum of source and drain depletion widths.

In this section, we will discuss various undesirable effects arising as a result of two-dimensional potential distribution and high electric fields in the short channel. The electron drift velocity in the channel is proportional to the electric field for lower electric field values.

These drift velocities tend to saturate at high electric fields. This is called velocity saturation. For short channel devices, the longitudinal electric field typically also increases.

It has been observed that, for the same gate voltage, the saturation mode of MOSFET is achieved at smaller values of drain-source voltage and saturation current reductions. Due to higher vertical electric fields, the carriers of the channel scatter off of the oxide interface. This results in the degradation of carrier mobility and the reduction in drain current.

Another short channel effect is called DIBL which refers to the reduction of threshold voltage at higher drain voltage. If the gate voltage is not sufficient to invert the surface i. By increasing gate potential, we eliminate this potential barrier.

But, for short channel devices, such a potential barrier is controlled by both V gs and V ds. If this drain voltage is increased, the depletion region of the drain-body increases in size and extends under the gate. So, the potential barrier in the channel decreases leading to carriers electrons flowing between source and drain, even at Vgs lower than Vt.