Thermodynamic Study on CVD Tungsten Silicide System

Polycrystalline atomic number 14 is commonly used as gate conductor, native association and electrical phenomenon plate in IC producing. However, with the continual improvement of circuit integration and also the additional reduction of device size, the resistance values of gate electrodes and crystalline atomic number 14 as an area association can increase, which can have an effect on the operating speed of the device. so as to scale back the gate resistance, a layer of atomic number 74 compound (WSix) is deposited on crystalline atomic number 14 to make a polycide composite gate structure, which might effectively scale back the gate resistance.

At constant time, the composite gate structure may be used because the bottom plate of metal and crystalline atomic number 14 electrical condenser (MIP), and also the precise capacitance may be obtained by modifying the crystalline atomic number 14 strip. However, in exercise, it’s found that once atomic number 74 compound grid is employed because the bottom plate of electrical condenser, it’s straightforward to exfoliate within the sequent method of aspect wall chemical compound film.

It’s believed that the plumbago base of CVD can cause some atomic number 14 whisker. it’s additionally believed that within the pre-cleaning method of WSix preparation, once the crystalline atomic number 14 is cleansed with evaporated fluoride (HF), there square measure phosphorus-containing substances on the surface of crystalline atomic number 14, which might simply mix with trace water vapour in evaporated HF to make HPO3 crystal. it’s additionally thought-about that the exfoliation of atomic number 74 compound film originates from the strain of atomic number 74 compound film itself.

Chemical vapor deposited (CVD) atomic number 74 compound films were shaped by a chilly wall reactor. These films were hardened in Formula to analyze changes in resistance, composition, thickness, and impurity. The modification in resistance once 1000°C tempering becomes larger because the film reaches the ratio price. A composition modification happens in an exceedingly film whose composition Si/W is quite a pair of.6. Excess Si within the Formula films Formula is lily-white within the boundary betweenFormula and poly‐Si. A thickness modification of concerning V-J Day happens once 1000°C tempering at Formula on Formula ; this price is smaller than the calculated price. F and H, that square measure impurities in Formula films decrease bit by bit and diffuse into gate Formula once 1000°C tempering.

Thermodynamic Study on CVD Tungsten Silicide System