Method of and apparatus for sputtering

A method for depositing a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber containing a gas atmosphere;
• applying to said target a first negative voltage of a first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect sputtering of the target material on said substrate by impinging of ions of the gas atmosphere on the target;
• and
• applying to said substrate a second negative voltage of a second waveform including a second negative base portion of a second substantially constant negative voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect reverse sputtering of the target material deposited on said substrate by impinging of ions of the gas atmosphere on the substrate.

A method for depositing a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber having introduced therein a gas atmosphere of argon or helium;
• applying to said target a first negative voltage of a first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect sputtering of the target material on said substrate by impinging of ions of the gas atmosphere on the target;
• and
• applying to said substrate a second negative voltage of a second waveform including a second negative base portion of a second substantially constant negative voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect reverse sputtering of the target material deposited on said substrate by impinging of ions of the gas atmosphere on the substrate.

A method for depositing a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber grounded to an earth potential;
• applying to said target a first negative voltage of a first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect sputtering of the target material on said substrate;
• and
• applying to said substrate a second negative voltage of a second waveform including a second negative base portion of a second substantially negative constant voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect reverse sputtering of the target material deposited on said substrate.

A method for forming a thin film of a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber;
• applying to said target a first negative voltage of a first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect sputtering of the target material on said substrate to form a thin film;
• and
• applying to said substrate a second negative voltage of a second waveform including a second negative base portion of a second substantially constant negative voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect reverse sputtering of the target material deposited on said substrate.

A method for depositing a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber;
• applying to said target a first negative voltage of a first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect sputtering of the target material on said substrate;
• applying to said substrate a second negative voltage of a second waveform including a second negative base portion of a second substantially constant negative voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect reverse sputtering of the target material deposited on said substrate;
• and
• applying high frequency power between said target and said substrate in said vacuum chamber.

A method for depositing a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber;
• applying to said target a first negative voltage including a first negative base portion of a first substantially constant negative voltage and a first high frequency portion which is alternately made active and inactive so as to effect sputtering of the target material on said substrate;
• and
• applying to said substrate a second negative voltage including a second negative base portion of a second substantially constant negative voltage and a second high frequency portion which is alternately made active and inactive in such a manner that a peak voltage value of said first high frequency portion during its active state is more negative than a peak voltage value of said second high frequency portion during its active state and the active state of said first high frequency portion does not substantially overlap with the active state of said second high frequency portion so as to effect reverse sputtering of the target material deposited on said substrate.

A method for depositing a material of a target on a substrate comprising the steps of:

• placing the target and the substrate opposing each other in a vacuum chamber;
• applying to said target evaporating power of a first waveform which provides alternately active and inactive states so as to evaporate the target material to be deposited on said substrate;
• and
• applying to said substrate a negative voltage of a second waveform which provides alternately active and inactive states so as to effect reverse sputtering of the target material deposited on said substrate wherein said active state of said first waveform does not substantially overlap with the active state of said second waveform.

An apparatus for forming a thin film of a material of a target on a substrate, said apparatus comprising:

• means for placing the target and the substrate at positions opposing each other in a vacuum chamber;
• means for applying to said target a first negative voltage of a first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect sputtering of the target material on said substrate;
• and
• means for applying to said substrate a bias current of a second negative voltage of a second waveform including a second negative base portion of a second substantially constant negative voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect reverse sputtering of the target material deposited on said substrate.

An apparatus for forming a thin film of a material of a target on a substrate, said apparatus comprising:

• means for placing the target and the substrate at positions opposing each other in a vacuum chamber;
• an optical waveform generator for generating first and second waveforms, said first waveform including a first negative base portion of a first substantially constant negative voltage and a first pulse portion including first pulses each having a first peak more negative than said first constant negative voltage so as to effect, when a negative voltage having said first waveform is applied to said target, sputtering of the target material on said substrate, and said second waveform including a second negative base portion of a second substantially constant negative voltage and a second pulse portion including second pulses each having a second peak more negative than said first constant negative voltage in such a manner that said second peak is less negative than said first peak and the second pulses do not substantially overlap with the first pulses so as to effect, when a negative voltage having said second waveform is applied to said substrate, reverse sputtering of the target material deposited on said substrate;
• a sputter power source connected to said target and receiving a signal indicative of said first waveform from said optional waveform generator to apply to said target a first negative voltage having said first waveform;
• and
• a reverse-sputter power source connected to said substrate and receiving a signal indicative of said second waveform from said optional waveform generator to apply to said substrate a second negative voltage having said second waveform.