Etch process for single crystal silicon

A process for etching shallow trenches in single crystal silicon, the process comprising the steps of:

• (a) placing single crystal silicon;
• (b) introducing into the chamber a process gas comprising HBr, Cl.sub.2, an inert gas and O.sub.2 ;
• (c) generating a plasma of the process gas in the chamber;
• and
• (d) contacting the single crystal silicon with the plasma in the chamber to etch shallow trenches in the single crystal silicon, the shallow trenches comprising opposed sidewalls, a bottom wall and bottom corners,
• wherein the shallow trenches have (i) rounded bottom corners, (ii) for a given trench width, a substantially uniform trench depth and trench profile angle across the single crystal silicon, (iii) a trench sidewall profile angle substantially independent of the trench depth, (iv) smooth and continuous trench sidewalls, and (v) substantially flat bottoms.

A process for etching shallow trenches in single crystal silicon, the process comprising the steps of:

• (a) placing a single crystal silicon into a chamber;
• (b) introducing into the chamber a process gas comprising chlorine, bromine, oxygen and an inert gas;
• (c) generating a plasma of the process gas in the chamber;
• and
• (d) contacting the single crystal silicon with the plasma in the chamber to etch shallow trenches in the single crystal silicon, the shallow trenches having (i) a depth of less than about 1 micron, and (ii) a substantially uniform trench depth and trench profile angle across the single crystal silicon for a given trench width.

A process for etching shallow trenches in single crystal silicon, the process comprising the steps of:

• (a) placing a single crystal silicon into a chamber;
• (b) introducing into the chamber a process gas comprised of chlorine, bromine, oxygen and an inert gas;
• (c) generating a plasma of the process gas in the chamber;
• and
• (d) contacting the single crystal silicon with the plasma in the chamber to etch shallow trenches in the single crystal silicon,
• wherein the shallow trenches have (i) a sidewall profile angle of from about 75.degree. to about 85.degree., and (ii) for a given trench width, a trench depth uniformity of less than about 3% and a substantially uniform sidewall profile angle across the single crystal silicon.

A process for etching shallow trenches in single crystal silicon, the process comprising the steps of:

• (a) placing a single crystal silicon on a cathode in a chamber, the cathode having a temperature of at least 60.degree. C. and the chamber having a pressure of from about 60 mTorr to about 90 mTorr;
• (b) introducing into the chamber a process gas comprising chlorine, bromine, oxygen and an inert gas;
• (c) generating a plasma of the process gas in the chamber;
• and
• (d) contacting the single crystal silicon with the plasma in the chamber to etch shallow trenches in the single crystal silicon, the shallow trenches having (i) a depth of less than about 1 micron, and (ii) a substantially uniform trench depth and trench profile angle across the single crystal silicon for a given trench width of the shallow trenches.

A process for etching shallow trenches in single crystal silicon, the process comprising the steps of:

• (a) placing a single crystal silicon on a cathode in a chamber, the cathode having a temperature of at least 60.degree. C. and the chamber having a pressure of from about 60 mTorr to about 90 mTorr;
• (b) introducing into the chamber a process gas comprising chlorine, bromine, O.sub.2 and He, the O.sub.2 and He being introduced at a flow rate of from about 10% to about 20% of the total flow rate of the process gas;
• (c) generating a plasma of the process gas in the chamber;
• and
• (d) contacting the single crystal silicon with the plasma in the chamber to etch shallow trenches in the single crystal silicon, the shallow trenches having (i) a depth of less than about 0.5 micron and a width of less than about 0.3 microns, (ii) a substantially uniform trench depth and trench profile angle across the single crystal silicon for a given trench width of the shallow trenches, and (iii) rounded bottom corners.

A process for etching shallow trenches in single crystal silicon, comprising the steps of:

• (a) placing a single crystal silicon having a patterned photoresist mask thereon on a cathode in an etching zone, the cathode being at a temperature of at least 60.degree. C.;
• (b) introducing into the etching zone a process gas comprising HBr, Cl.sub.2 and oxygen;
• (c) generating a plasma from the process gas;
• and
• (d) contacting the single crystal silicon with the plasma to form shallow trenches.