Solution preparation apparatus and method for treating individual semiconductor workpiece
OwnerYue Ma, Chuan He +3inventors
InventorsYue Ma, Chuan He, Guangtao Shi, Voha Nuch, Hui Wang
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Abstract
The invention discloses a low-cost apparatus for chemical solution preparation with controlled process parameters such as chemical age, temperature, yield of active ingredients at the point of use. In addition, this apparatus provides chamber-to-chamber consistency on these parameters across multiple processing chambers on a single wafer wet-clean system. The invention also discloses a method to use chemical solution mixture resident time to achieve optimal combined effect of temperature, reactivity and yield of active ingredients of chemical solution mixture for best wafer treatment results.
Claims22
A chemical solution preparation apparatus for treating individual semiconductor workpiece comprising:
- a) at least one member heating one chemical to a temperature T—0;
- b) a plurality of pumps and flow control device for transporting and controlling individual chemicals;
- c) one blending vessel, where pre-heated chemicals are introduced, mixed and reacted into a chemical solution mixture for a controlled resident time, t_r, prior to dispensing freshly mixed chemical solution in the vessel to one semiconductor workpiece in one processing chamber;
- t_r controls the activity and temperature of the chemical solution mixture at point of use;
- d) a software control system that sets a flag to introduce individual chemicals into said blending vessel at time t;
- e) at least one chemical dispense nozzle connected to at least one chemical delivery line from said blending vessel for one processing chamber.
A method of chemical solution preparation for treating individual semiconductor workpiece comprising:
- a) generate temperature vs. time curves for a chemical solution mixture to be used at different initial temperatures;
- b) run a group of wafers using a full dummy sequence with desired processing times for each chemical solution mixture on the cleaning system to extract the minimum time (t_min) from when said chemical solution mixture completed dispensing to when said chemical solution mixture was dispensed again between adjacent wafers processed in the same chamber of cleaning system;
- Choose the smallest t_min across all chambers;
- c) determine processing parameters of the said apparatus based on desired chemical concentration, temperature at point of use (T), chemical delivery rate (q), and the amount of the chemical to be dispensed (Q), for a given cleaning process, these parameters including:
- T—0, t_r, t_i, and t_d;
- d) set these processing parameters for said chemical solution mixture in the control software;
- e) control software validates processing parameters;
- Returns error and request new input if parameters are invalid;
- f) process semiconductor workpiece;
- g) said pressure release valve of said blending vessel is in open state;
- h) as semiconductor workpiece is going through the process, fill process of a said blending vessel by individual chemicals begins at t=t_f−t_r−t_l;
- i) as semiconductor workpiece is going through the process, fill process of a said blending vessel by individual chemicals stops at t=t_f−t_r;
- the volume of said chemical solution mixture in said vessel=Q;
- j) as semiconductor workpiece is going through the process and is ready to receive treatment by said chemical solution mixture, said pressure release valve of said blending vessel closes, said blending vessel is open to pressurized gas at a fixed pressure, and said chemical solution mixture in the vessel begins to dispense at t=t_f;
- k) as semiconductor workpiece is going through the process, said chemical solution mixture in the vessel completes dispensing at t=t_f+t_d, and the total volume of said chemical solution mixture dispensed=Q. Purge begins and lasts for t_p;
- l) as semiconductor workpiece is going through the process, said pressure release valve of said blending vessel opens and said blending vessel is closed to pressurized gas at t=t_f+t_d+t_p;
- m) semiconductor workpiece is ready for the next treatment step in the process;
- n) steps (f)-(m) repeat for each wafer.
Dependencies are inferred from the claim text.