Semiconducting devices and method of making thereof

Abstract

The invention relates to a process for providing semiconducting device comprising the steps of depositing a semiconducting layer onto a substrate by heating a gas to a predetermined dissociation temperature so that the gas dissociates into fractions, whereby these fractions subsequently condense on the substrate to build up a semiconducting layer.

1 . Process for providing a semiconducting device comprising the steps of: 
 depositing a semiconducting layer onto a substrate by means of heating a gas to a predetermined, dissociation temperature so that the gas dissociates into fractions, whereby these fractions subsequently condense on the substrate to build up a semiconducting layer.    
     
     
         2 . Process according to    claim 1    wherein the gas is heated by heat radiating from a heating element.  
     
     
         3 . Process according to    claim 2    wherein the heating element comprises a tungsten element.  
     
     
         4 . Process according to any of the preceding claims, wherein the carrier is a silicon wafer.  
     
     
         5 . Process according to    claim 4   , wherein the silicon wafer is thermally oxidized.  
     
     
         6 . Process according to any of the claims  1 - 3 , wherein the carrier is made of glass.  
     
     
         7 . Process according to any of the previous claims, wherein the gas is a silicon containing gas.  
     
     
         8 . Process according to    claim 7   , wherein the silicon containing gas comprises silane.  
     
     
         9 . Process according to any of the previous claims wherein the gas is heated to a temperature in the range of 500-3000° C., preferably 1600-2000° C. and especially in the case of tungsten most preferably to a temperature of about 1750° C.  
     
     
         10 . Process according to any of the previous claims, wherein the substrate is pretreated with a treatment gas before deposition of the semiconducting layer is carried out.  
     
     
         11 . Process according to    claim 10   , wherein the pretreatment gas comprises hydrogen.  
     
     
         12 . Process according to any of the preceding claims wherein the substrate is periodically isolated from the heating element, and/or the silicon containing gas, and/or the pretreatment gas.  
     
     
         13 . Process according to any of the previous claims, carried out in a vacuum vessel.  
     
     
         14 . Process according to any of the previous claims, carried out at a pressure greater than 10 −6  millibar, preferably at a pressure between 15 and 500 microbar, most preferably at a pressure of 20 microbar.  
     
     
         15 . Process according to any of the previous claims, wherein the gas is guided through the vacuum vessel at a rate of between 20 and 150 standard cm 3 /minute and most preferably with a gas flow of 90 standard cm 3 /minute.  
     
     
         16 . Process according to any of the previous claims, wherein the substrate is heated to a temperature of between 200 and 600° C., preferably to a temperature of between 400 and 450° C. and most preferably to a temperature of 430° C.  
     
     
         17 . Process according to any of the previous claims, wherein following deposition of the semiconducting layer, the device is cooled.  
     
     
         18 . Process according to    claim 17    wherein the device is cooled by guiding silane gas through the vacuum vessel.  
     
     
         19 . Process according to    claim 17    or    18   , whereafter a highly doped semiconducting layer is deposited on the semiconducting layer.  
     
     
         20 . Process according to    claim 19   , wherein the highly doped semiconducting layer is deposited by means of radiofrequency glow discharge.  
     
     
         21 . Process according to    claim 20   , wherein prior to the deposition of the highly doped semiconducting layer, the surface bonds of the deposited semiconducting layer are passivated, preferably by treating these with H 2  plasma.  
     
     
         22 . Device, in particular being a transistor, said device having a substantially consistent gate voltage and a saturation mobility μ, in the range of about 0.001 to about 100, for example about 0.001 to about 10 and most preferably from about 0.1 to about 1.00 cm 2 /V.s.  
     
     
         23 . Device obtainable according to the process according to any of the claims  1 - 21 , which device has a substantially consistent gate voltage and having a saturation mobility in the range of about 0.001 to about 100, for example about 0.001 to about 10 and most preferably from about 0.1 to about 1.00 cm 2 /V.s.  
     
     
         24 . Device comprising a substantially exclusive polycrystalline Si:H or a polycrystalline and amorphous Si:H layer, said device having a substantially consistent gate voltage and a saturation mobility lying in the range of about 0.001-1000, for example 0.001 to 500 cm 2 /V.s.  
     
     
         25 . Vacuum chamber for carrying out the process according to any of the claims  1 - 21 , comprising a gas inlet, a gas outlet, a gas heating element, and a substrate heater.  
     
     
         26 . Vacuum chamber according to    claim 24   , further comprising a shutter element arrangeable between the gas heating element and a substrate.  
     
     
         27 . Vacuum chamber according to    claim 25    or    26   , further comprising a radiofrequency electrode for plasma enhanced chemical vapor deposition.