Pulsed dual radio frequency CVD process

In the use of plasma or glow discharge to transfer energy into reactant gases so as to deposit silicon oxynitride onto semiconductor substrate or onto a layer formed on the semiconductor substrate in a reaction chamber, an improved method comprising:

• generating a first radio frequency pulse with a frequency of approximately 55 KHz;
• striking a gas in said reaction chamber with said first pulse;
• applying a second radio frequency pulse to said gas while said first pulse is still being generated, said second pulse being generated at a frequency of approximately 13.56 MKz;
• switching off said first pulse after a first predetermined span of time while said second pulse is still being generated;
• switching off said second pulse after a second perdetermined span of time;
• repeating said pulses after a third predetermined span of time over a deposition period thereby generating a series of periodic pulses.

In the use of a radio frequency field to form glow discharge or a plasma in reaction chamber so as to transfers energy to reactant gases wherein silicon oxynitride is deposited onto a semiconductor substrate or on a layer formed on the semiconductor substrate, an improved method comprising:

• generating a first radio frequency pulse of a first frequency and of a first pulse width;
• striking a gas in said reaction chamber with said first pulse;
• triggering a second radio frequency pulse with the leading edge of said first pulse;
• generating said second pulse at a second frequency and a second pulse width, said first frequency being lower than said second frequency, and said second pulse width being greater than said first pulse width;
• repeating said pulses over a predetermined deposition period thereby generating a series of periodic pulses.

In the use of plasma or glow discharge to transfer energy into reactant gases to deposit silicon oxynitride onto a semiconductor substrate or on a layer formed on the semiconductor substrate in a reaction chamber, an improved method comprising:

• generating a first radio frequency pulse of a first frequency and of a first pulse width;
• striking gas in said reaction chamber with said first pulse;
• triggering a second radio frequency pulse with the trailing edge of said first pulse;
• generating said second pulse at a second frequency and a second pulse width, said first frequency being lower than said second frequency, and said second pulse width being greater than said first pulse width;
• repeating said pulses over a predetermined deposition period thereby generating a series of periodic pulses.

In the use of a radio frequency field to form glow discharge or a plasma in a reaction chamber so as to transfer energy to reactant gases wherein silicon oxynitride is deposited onto a semiconductor substrate or on a layer formed on the semiconductor substrate, an improved method comprising:

• generating a first radio frequency pulse;
• striking a gas in said reaction chamber with said first pulse;
• triggering a second radio frequency pulse with the trailing edge of said first pulse;
• generating a third radio frequency pulse after said second pulse;
• said first and third pulse being of the same radio frequency and being lower in frequency than said second pulse;
• repeating said pulses over a predetermined deposition period thereby generating a series of periodic pulses.