Process for fabricating films of uniform properties on semiconductor devices

Abstract

A process for forming a thin layer exhibiting a substantially uniform property on an active surface of a semiconductor substrate. The process includes varying the temperature within a reaction chamber while a layer of a material is formed upon the semiconductor substrate. Varying the temperature within the reaction chamber facilitates temperature uniformity across the semiconductor wafer. As a result, a layer forming reaction occurs at a substantially consistent rate over the entire active surface of the semiconductor substrate. The process may also include oscillating the temperature within the reaction chamber while a layer of a material is being formed upon a semiconductor substrate.

What is claimed is:  
     
         1 . A process for forming a film on a semiconductor substrate, comprising: 
 placing the semiconductor substrate into a reaction chamber;    substantially continually varying a temperature within said reaction chamber; and    introducing matter of a type to promote formation of the film into said reaction chamber in proximity to an exposed surface of the semiconductor substrate while substantially continually varying the temperature.    
     
     
         2 . The process of  claim 1 , further including forming the film to exhibit at least one substantially uniform property thereacross.  
     
     
         3 . The process of  claim 2 , wherein said forming comprises forming the film to exhibit at least one substantially uniform property comprising at least one of thickness, sheet resistance, reflectivity, transmissivity, absorptivity, etch characteristics, dopant distribution, and dielectric constant.  
     
     
         4 . The process of  claim 1 , wherein said substantially continually varying comprises increasing the temperature within said reaction chamber from a first temperature to a second temperature.  
     
     
         5 . The process of  claim 4 , further comprising cycling the temperature within the reaction chamber following said increasing to said second temperature, said cycling including decreasing the temperature within said reaction chamber at least once to at least about said first temperature and re-increasing the temperature within said reaction chamber at least once to about said second temperature.  
     
     
         6 . The process of  claim 1 , wherein said substantially continually varying comprises decreasing the temperature within said reaction chamber from a first temperature to a second temperature.  
     
     
         7 . The process of  claim 6 , further comprising cycling the temperature within the reaction chamber following said decreasing, said cycling including increasing the temperature within said reaction chamber at least once to at least about said first temperature and re-decreasing the temperature within said reaction chamber at least once to about said second temperature.  
     
     
         8 . The process of  claim 1 , wherein said substantially continually varying comprises fluctuating the temperature within said reaction chamber.  
     
     
         9 . The process of  claim 8 , comprising effecting said fluctuating during a temperature ramp-up prior to forming the film.  
     
     
         10 . The process of  claim 8 , comprising effecting said fluctuating during a temperature ramp-down subsequent to forming the film.  
     
     
         11 . The process of  claim 8 , comprising effecting said fluctuating during a substantially steady-state temperature trend.  
     
     
         12 . The process of  claim 8 , wherein said fluctuating comprises varying the temperature at a constant frequency.  
     
     
         13 . The process of  claim 8 , further comprising altering an overall temperature trend from a first phase to a second phase.  
     
     
         14 . The process of  claim 8 , further comprising altering a frequency of said fluctuating.  
     
     
         15 . The process of  claim 8 , further comprising altering a magnitude of said fluctuating.  
     
     
         16 . The process of  claim 8 , further comprising monitoring an initial growth pattern of the film.  
     
     
         17 . The process of  claim 16 , further comprising optimizing a frequency of said fluctuating responsive to said initial growth pattern of the film to enhance uniformity of at least one property of the film.  
     
     
         18 . The process of  claim 17 , wherein said enhancing uniformity of said at least one property of the film includes enhancing uniformity of at least one of thickness, sheet resistance, reflectivity, transmissivity, absorptivity, etch characteristics, dopant distribution, and dielectric constant.  
     
     
         19 . The process of  claim 16 , further comprising optimizing a magnitude of said fluctuating responsive to said initial growth pattern of the film to enhance uniformity of at least one property of the film.  
     
     
         20 . The process of  claim 19 , wherein said enhancing uniformity of said at least one property of the film includes enhancing uniformity of at least one of thickness, sheet resistance, reflectivity, transmissivity, absorptivity, etch characteristics, dopant distribution, and dielectric constant.  
     
     
         21 . The process of  claim 1 , further comprising monitoring an overall growth pattern of the film.  
     
     
         22 . The process of  claim 21 , further comprising altering the temperature within said reaction chamber responsive to said monitoring.  
     
     
         23 . The process of  claim 21 , further comprising altering a rate of said substantially continually varying responsive to said monitoring.  
     
     
         24 . The process of  claim 21 , further comprising cycling the temperature within said reaction chamber following said substantially continually varying.  
     
     
         25 . The process of  claim 1 , further comprising monitoring the temperature of selected portions of the semiconductor substrate.  
     
     
         26 . The process of  claim 1 , wherein said substantially continually varying is effected by altering a frequency, an amplitude, or a phase power characteristic.  
     
     
         27 . A method of semiconductor substrate temperature and layer formation process uniformity control, comprising: 
 placing a semiconductor substrate into a reaction chamber;    substantially continuously varying a temperature within said reaction chamber; and introducing matter of a type to promote formation of a layer of a material into said reaction chamber in proximity to an exposed surface of the semiconductor substrate while varying the temperature.    
     
     
         28 . The method of  claim 27 , wherein, following said introducing, said layer exhibits at least one substantially uniform property.  
     
     
         29 . The method of  claim 28 , wherein at least said substantially continuously varying said temperature effects formation of said layer, with said at least one substantially uniform property comprising at least one of thickness, sheet resistance, reflectivity, transmissivity, absorptivity, etch characteristics, dopant distribution, and dielectric constant.  
     
     
         30 . The method of  claim 27 , wherein said substantially continuously varying comprises increasing the temperature within said reaction chamber.  
     
     
         31 . The method of  claim 30 , further comprising cycling the temperature within the reaction chamber following said increasing, said cycling including decreasing and re-increasing the temperature within said reaction chamber at least once.  
     
     
         32 . The method of  claim 27 , wherein said substantially continuously varying comprises decreasing the temperature within said reaction chamber.  
     
     
         33 . The method of  claim 32 , further comprising cycling the temperature within the reaction chamber following said decreasing, said cycling including increasing and re-decreasing the temperature within said reaction chamber at least once.  
     
     
         34 . The method of  claim 27 , wherein said substantially continuously varying comprises fluctuating the temperature within said reaction chamber.  
     
     
         35 . The method of  claim 34 , further comprising effecting said fluctuating during a temperature ramp-up prior to forming the layer.  
     
     
         36 . The method of  claim 34 , further comprising effecting said fluctuating during a temperature ramp-down subsequent to forming the layer.  
     
     
         37 . The method of  claim 34 , further comprising effecting said fluctuating during forming the layer.  
     
     
         38 . The method of  claim 34 , wherein said fluctuating comprises varying the temperature at a constant frequency.  
     
     
         39 . The method of  claim 34 , further comprising altering an overall temperature trend from a first phase to a second phase.  
     
     
         40 . The method of  claim 34 , further comprising altering a frequency of said fluctuating.  
     
     
         41 . The method of  claim 34 , further comprising altering a magnitude of said fluctuating.  
     
     
         42 . The method of  claim 34 , further comprising optimizing a frequency of said fluctuating responsive to an initial growth pattern of the layer to enhance uniformity of at least one property of the layer.  
     
     
         43 . The method of  claim 42 , wherein said optimizing comprises enhancing uniformity of at least one of thickness, sheet resistance, reflectivity, transmissivity, absorptivity, etch characteristics, dopant distribution, and dielectric constant of the layer.  
     
     
         44 . The method of  claim 34 , further comprising optimizing a magnitude of said fluctuating responsive to an initial growth pattern of the layer to enhance uniformity of at least one property of the layer.  
     
     
         45 . The method of  claim 44 , wherein said optimizing comprises enhancing uniformity of at least one of thickness, sheet resistance, reflectivity, transmissivity, absorptivity, etch characteristics, dopant distribution, and dielectric constant of the layer.  
     
     
         46 . The method of  claim 27 , further comprising monitoring an overall growth pattern of the layer.  
     
     
         47 . The method of  claim 46 , further comprising altering the temperature within said reaction chamber responsive to said monitoring.  
     
     
         48 . The method of  claim 46 , further comprising altering a rate of said varying responsive to said monitoring.  
     
     
         49 . The method of  claim 46 , further comprising cycling the temperature within said reaction chamber following said substantially continuously varying.  
     
     
         50 . The method of  claim 27 , further comprising monitoring the temperature of selected portions of the semiconductor substrate.  
     
     
         51 . The method of  claim 27 , wherein said substantially continuously varying comprises altering a frequency, an amplitude, or a phase power characteristic.