Alternating asymmetrical plasma generation in a process chamber

Abstract

Embodiments of the invention generally provide etch or CVD plasma processing methods and apparatus used to generate a uniform plasma across the surface of a substrate by modulation pulsing the power delivered to a plurality of plasma controlling devices found in a plasma processing chamber. The plasma generated and/or sustained in the plasma processing chamber is created by the one or more plasma controlling devices that are used to control, generate, enhance, and/or shape the plasma during the plasma processing steps by use of energy delivered from a RF power source. Plasma controlling devices may include, for example, one or more coils (inductively coupled plasma), one or more electrodes (capacitively coupled plasma), and/or any other energy inputting device such as a microwave source.

1 . A plasma chamber for plasma processing a substrate, comprising: 
 a first plasma controlling device in communication with a processing region of a plasma chamber, wherein the first plasma controlling device is connected to a first RF power source;    a second plasma controlling device in communication with the processing region of the plasma chamber, wherein the second plasma controlling device is connected to a second RF power source; and    a controller adapted to synchronize the amplitude modulation of the RF power delivered to the first plasma controlling device and the second plasma controlling device such that the shape of the amplitude modulated waveform and overlap in time of the RF power supplied to the first and second plasma controlling devices is controlled to improve the uniformity of the plasma process completed on a substrate mounted in the processing region.    
   
   
       2 . The plasma chamber of  claim 1 , wherein the controller, the first RF power source, and the second RF power source modulate the amplitude of the RF power, and wherein modulating the amplitude of the RF power includes synchronizing the RF power delivered to the first and second plasma controlling devices, controlling the ratio of power delivered to the first and second plasma controlling devices, and controlling the shape and duration of the amplitude modulated power.  
   
   
       3 . The plasma chamber of  claim 1 , wherein the shape of the amplitude modulated RF power supplied to the first and second plasma controlling devices, is rectangular in shape, trapezoidal in shape, triangular in shape or sinusoidal in shape.  
   
   
       4 . The plasma chamber of  claim 1 , wherein the amplitude modulated RF power is rectangular in shape and the amplitude modulated RF power supplied to the second plasma controlling devices is at 0 Watts when the first plasma controlling device is at a power level greater than 0 Watts, and the amplitude modulated RF power supplied to the first plasma controlling devices is 0 Watts when the second plasma controlling device is at a power level greater than 0 Watts.  
   
   
       5 . The plasma chamber of  claim 1 , wherein the amplitude modulated RF power is rectangular in shape and the amplitude modulated RF power supplied to the first plasma devices and the second plasma controlling device overlap an amount less than the full pulse width.  
   
   
       6 . The plasma chamber of  claim 1 , wherein the controller, the first RF power source, and the second RF power source control the interaction of the plasma generated by the first and second plasma controlling devices by varying the frequency of the amplitude modulations of the RF power.  
   
   
       7 . The plasma chamber of  claim 1 , wherein the overlap in time is a rest time between the amplitude modulations of the RF power.  
   
   
       8 . The plasma chamber of  claim 1 , wherein the first plasma controlling device is an inductive coil, an electrode or a torroidal source.  
   
   
       9 . The plasma chamber of  claim 1 , wherein the second plasma controlling device is an inductive coil, an electrode or a torroidal source.  
   
   
       10 . The plasma chamber of  claim 1 , further comprising a pedestal that is adapted to support the substrate, wherein the pedestal is connected to a third RF power source that is capable of amplitude modulation of the RF power delivered to the pedestal.  
   
   
       11 . The plasma chamber of  claim 10 , further comprising a fourth RF power source connected to the pedestal that is capable of amplitude modulation of the RF power delivered to the pedestal, wherein the RF frequency of the fourth RF power source is greater than the RF frequency of the third RF power source.  
   
   
       12 . A plasma chamber for processing a substrate, comprising: 
 a first plasma controlling device connected to a first RF power source that is capable of amplitude modulation of the RF power delivered to the first plasma controlling device;    a second plasma controlling device connected to a second RF power source that is capable of amplitude modulation of the RF power delivered to the second plasma controlling device;    a third plasma controlling device connected to a third RF power source that is capable of amplitude modulation of the RF power delivered to the third plasma controlling device; and    a controller adapted to synchronize the amplitude modulation of the RF power delivered to the first plasma controlling device, the second plasma controlling device and the third plasma controlling device such that the shape of the amplitude modulated waveform and overlap in time of the RF power supplied to the first, second and third plasma controlling devices is controlled to improve the uniformity of the plasma process completed on a substrate mounted in the processing region.    
   
   
       13 . The plasma chamber of  claim 12 , wherein the first plasma controlling device is an inductive coil, an electrode, or a torroidal source.  
   
   
       14 . The plasma chamber of  claim 12 , wherein the second plasma controlling device is an inductive coil, an electrode, or a torroidal source.  
   
   
       15 . The plasma chamber of  claim 12 , wherein the third plasma controlling device is a torroidal source, an inductive coil, or a electrode.  
   
   
       16 . The plasma chamber of  claim 12 , further comprising a pedestal that is adapted to support the substrate, wherein the pedestal is connected to a fourth RF power source that is capable of amplitude modulation of the RF power delivered to the pedestal.  
   
   
       17 . The plasma chamber of  claim 16 , further comprising a fifth RF power source connected to the pedestal that is capable of amplitude modulation of the RF power delivered to the pedestal, wherein the RF frequency of the fifth power source is greater than the RF frequency of the fourth RF power source.  
   
   
       18 . The plasma chamber of  claim 12 , wherein the overlap in time is a rest time between the amplitude modulations of the RF power.  
   
   
       19 . A method of processing a substrate in a plasma chamber, comprising: 
 amplitude modulating the RF power delivered to a first plasma controlling device at a first modulation pulse frequency and at a first power level;    amplitude modulating the RF power delivered to a second plasma controlling device at a second modulation pulse frequency and at a second power level;    synchronizing the amplitude modulation of the RF power to the first plasma controlling device and the second plasma controlling device; and    controlling the amplitude modulation of the RF power such that the overlap in time and the shape of the amplitude modulated RF power delivered to the first and second plasma controlling devices is controlled to improve the uniformity of the process completed on the substrate.    
   
   
       20 . The method of  claim 19 , wherein the first modulation pulsing frequency and the second modulation pulsing frequency are between about 0.1 Hz and about 100,000 Hz.  
   
   
       21 . The method of  claim 19 , wherein the first RF power level and the second RF power level are between about 0 Watts and about 5000 Watts.  
   
   
       22 . The method of  claim 19 , wherein the ratio of the first RF power level to the second RF power level or the second RF power level to the first RF power level is between about 1:1 and about 100:1.  
   
   
       23 . The method of  claim 19 , wherein the first plasma controlling device is an inductive coil, an electrode, or a torroidal source.  
   
   
       24 . The method of  claim 19 , wherein the second plasma controlling device is an inductive coil, an electrode or a torroidal source.  
   
   
       25 . The method of  claim 19 , wherein the amplitude modulating of the RF power supplied to the second plasma controlling devices is less than the first plasma controlling device at a first time, and the RF power supplied to the first plasma controlling devices is less than the second plasma controlling device at a second time.  
   
   
       26 . The method of  claim 19 , wherein the shape of the amplitude modulated RF power is rectangular in shape, trapezoidal in shape, triangular in shape or sinusoidal in shape.  
   
   
       27 . The method of  claim 19 , further comprising: 
 amplitude modulating the RF power delivered to a third plasma controlling device at a third modulation pulsing frequency and at a third power level;    synchronizing the amplitude modulating of the RF power to the first, second and third plasma controlling devices; and    controlling the amplitude modulation of the RF power such that the overlap of the amplitude modulated RF power delivered to the first, second and third plasma controlling devices is controlled to improve the uniformity of the process completed on the substrate.    
   
   
       28 . A method of processing a substrate in a plasma chamber, comprising: 
 generating a first torroidal path of plasma that passes near and transverse a surface of the substrate using a first torroidal plasma controlling device;    generating a second torroidal path of plasma that passes near and transverse a surface of the substrate using a second torroidal plasma controlling device, wherein the first torroidal path is not coincident to the second torroidal path; and    varying the plasma density in the vicinity of the substrate by amplitude modulating the first torroidal path of plasma at a first modulation pulsing frequency and a first RF power and modulation pulsing the second torroidal path of plasma at a second modulation pulsing frequency and a second RF power as a function of time.    
   
   
       29 . The method of  claim 28 , wherein the first modulation pulsing frequency and the second modulation pulsing frequency are between about 0.1 Hz and about 100,000 Hz.  
   
   
       30 . The method of  claim 28 , wherein the first RF power level and the second RF power level are between about 0 Watts and about 5000 Watts.  
   
   
       31 . The method of  claim 28 , wherein the ratio of the first RF power to the second RF power level is between about 1:1 and about 100:1.  
   
   
       32 . A method of processing a substrate in a plasma chamber, comprising: 
 generating a plasma over a surface of a substrate using a first plasma controlling device;    generating a plasma over a surface of the substrate using a second plasma controlling device, wherein the first plasma controlling device generates a plasma in a first region near the substrate and the second plasma controlling device generates a plasma in a second region near the substrate and the first and second regions overlap; and    varying the plasma density generated in the first region, in the second region, and a region between the first and second region by amplitude modulating the RF power delivered to the first plasma controlling device and the second plasma controlling device.    
   
   
       33 . The method of  claim 32 , wherein the first modulation pulse frequency and the second modulation pulse frequency are between about 0.1 Hz and about 100,000 Hz.  
   
   
       34 . The method of  claim 32 , wherein the first RF power level and the second RF power level are between about 0 Watts and about 5000 Watts.  
   
   
       35 . The method of  claim 32 , wherein the ratio of the first RF power to the second RF power ev is between about 1:1 and about 100:1.  
   
   
       36 . The method of  claim 32 , wherein the first plasma controlling device is a first inductive coil and the second plasma controlling device is a second inductive coil.  
   
   
       37 . The method of  claim 32 , wherein the first plasma controlling device is a first electrode and the second plasma controlling device is a second electrode.  
   
   
       38 . The method of  claim 32 , wherein the first plasma controlling device is a first torroidal source and the second plasma controlling device is a second torroidal source.  
   
   
       39 . A method of processing a substrate in a plasma chamber, comprising: 
 amplitude modulating the RF power to a first plasma controlling device at a first modulation pulse frequency and at a first power level;    amplitude modulating the RF power to a second plasma controlling device at a second modulation pulse frequency and at a second power level;    synchronizing the amplitude modulation of the RF power to the first plasma controlling device and the second plasma controlling device; and    varying the first and second modulation pulse frequencies to adjust the plasma density in a plasma chamber to compensate for a non-uniform area on a substrate surface.    
   
   
       40 . A method of processing a substrate in a plasma chamber, comprising: 
 amplitude modulating the RF power to a first plasma controlling device at a first modulation pulse frequency and at a first power level;    amplitude modulating the RF power to a second plasma controlling device at a second modulation pulse frequency and at a second power level;    synchronizing the amplitude modulation of the RF power to the first plasma controlling device and the second plasma controlling device; and    controlling the shape of the amplitude modulated RF power to the first and second plasma controlling devices, wherein the shape of the amplitude modulated RF power is rectangular, trapezoidal, triangular or sinusoidal.    
   
   
       41 . A method of processing a substrate in a plasma chamber, comprising: 
 amplitude modulating the RF power to a first plasma controlling device at a first modulation pulse frequency and at a first power level;    amplitude modulating the RF power to a second plasma controlling device at a second modulation pulse frequency and at a second power level;    synchronizing the amplitude modulation of the RF power to the first plasma controlling device and the second plasma controlling device,    controlling the shape of the amplitude modulated RF power to the first and second plasma controlling devices; and    controlling the overlap and/or gap between the amplitude modulated RF power to the first plasma controlling device and the second plasma controlling device.    
   
   
       42 . A method of processing a substrate in a plasma chamber, comprising: 
 amplitude modulating the RF power to a first plasma controlling device at a first modulation pulse frequency and at a first power level;    amplitude modulating the RF power to a second plasma controlling device at a second modulation pulse frequency and at a second power level;    synchronizing the amplitude modulation of the RF power to the first plasma controlling device and the second plasma controlling device,    controlling the amplitude modulation of the RF power to the first plasma controlling device and amplitude modulation of the RF power to the second plasma controlling device such that the power, modulation pulse frequency, modulation pulse duration, rest time between modulation pulses, and overlap of the modulation pulse to the first and/or second plasma controlling devices can be varied as a function of time.