Method and apparatus of etching a clean trench in a semiconductor material

A method of etching a semiconductor material within a process chamber, comprising the steps of:

• providing an electrode within said process chamber which supports the semiconductor material;
• executing the first part of a two part process on said semiconductor material for a first predetermined time period, wherein the first part comprises the steps of:
• (a) applying a first power supply at a first predetermined level to said electrode of a process chamber, the first power supply operating at a first frequency;
• (b) simultaneously applying a second power supply to the electrode at a second power output level, the second power supply operating at a second frequency, the first frequency being substantially greater than the second frequency to provide anisotropic control of the trench etching;
• and
• (c) introducing a plasma chemistry within the process chamber to selectively etch said semiconductor material, the plasma chemistry containing materials that do not produce a buildup of sidewall deposition on areas etched away within said semiconductor material or residue within the process chamber;
• and
• subsequently executing the second part of said two part process on said semiconductor material for a second predetermined time period, wherein said second part comprises the steps of:
• (d) applying said first power supply operating at said first frequency at a third power level;
• (e) applying said second power supply operating at said second frequency at a fourth power level;
• and
• (f) etching said semiconductor material a second time by exciting said plasma chemistry with the energies from said first and second power supplies.

A method of etching a semiconductor material within a process chamber, comprising the steps of:

• providing a process chamber having at least one electrode, said semiconductor material being placed on said electrode;
• providing a plasma chemistry within said process chamber, said plasma chemistry comprising hydrogen bromide and boron trichloride;
• executing a three part etching process, wherein the first part comprises the steps of:
• (a) applying a high frequency power supply to said electrode at a first power output level;
• (b) simultaneously applying a low frequency power supply to said electrode at a second power output level;
• and
• (c) allowing said plasma chemistry to etch said semiconductor material while being excited by said high and low frequency power supplies for a predetermined time period;
• subsequently executing the second part of said three part process, wherein said second part comprises the steps of:
• (d) adding chlorine to said plasma chemistry;
• (e) applying said high frequency power supply to said electrode at said first power output level;
• (f) simultaneously applying said low frequency power supply to said electrode at said second power output level;
• and
• (g) allowing said plasma chemistry to etch said semiconductor material while being excited by said high and low frequency power supplies for a second predetermined time period;
• and
• subsequently executing the third part of said three part process, wherein said third part comprises the steps of:
• (h) removing the hydrogen bromide from said plasma chemistry;
• (i) applying said high frequency power supply to said electrode at a third power output level;
• (j) simultaneously applying said low frequency power supply to said electrode at fourth power output level;
• and
• (k) allowing the plasma chemistry to etch the semiconductor material while being excited by said high and low frequency signals for a third predetermined time period.