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CN-122028683-A - A multichamber vertical furnace for semiconductor trade thermal treatment

CN122028683ACN 122028683 ACN122028683 ACN 122028683ACN-122028683-A

Abstract

The invention relates to the field of semiconductor manufacturing equipment, in particular to a multi-chamber vertical furnace for heat treatment in the semiconductor industry, which comprises a plurality of mutually independent process cavities, wherein a conveying mechanism comprises a bracket capable of rotating around a central shaft, a moving mechanism for driving the bracket to lift and fall and a plurality of furnace doors corresponding to the number of the process cavities, each furnace door is used for bearing a wafer boat, the conveying mechanism rotates the furnace door bearing the wafer boat below a target process cavity, drives the furnace door to lift and butt joint with the target process cavity and form a closed treatment cavity, descends and rotates to a next cavity or an unloading position after the process is completed, seamless transportation of the wafer boat among different process environments is realized, a process intelligent scheduling system dynamically distributes wafers to the target process cavities based on a reinforcement learning algorithm, and a gas pollution prevention and control system adopts a neural network model to predict residual gas concentration and automatically triggers a cleaning flow when the residual gas concentration exceeds a preset threshold. The invention improves the production efficiency and the product quality.

Inventors

  • YANG CHEN
  • WANG LIANFU
  • Ruan Tiebin
  • ZHONG HUA
  • WANG ZHENQIANG

Assignees

  • 北京和崎精密科技有限公司

Dates

Publication Date
20260512
Application Date
20260318

Claims (10)

  1. 1. A multi-chamber vertical furnace for heat treatment in the semiconductor industry, comprising: a plurality of mutually independent process cavities, wherein each process cavity is provided with an independent temperature control system and an independent atmosphere control system; The conveying mechanism comprises a bracket capable of rotating around a central shaft, a moving mechanism for driving the bracket to lift and a plurality of furnace doors which are arranged on the bracket and correspond to the number of the process cavities, and each furnace door is used for bearing one wafer boat; the conveying mechanism is configured to rotate a furnace door carrying the wafer boat below the target process cavity, drive the furnace door to ascend and butt joint with the corresponding target process cavity, and lock the furnace door to form a closed treatment cavity; the process intelligent scheduling system is used for dynamically distributing the wafer to the target process cavity based on the reinforcement learning algorithm; The gas pollution prevention and control system is used for predicting the concentration of residual gas in the next process cycle by adopting an LSTM neural network model and automatically and compositely triggering the cleaning flow when the predicted value exceeds a preset threshold value.
  2. 2. The multi-chamber vertical furnace for heat treatment in the semiconductor industry of claim 1 wherein the state space of the intelligent process scheduling system is comprised of real-time temperature of each process chamber, process gas concentration within each process chamber, three-dimensional position coordinates of the wafer boat, priority of wafer lot to be processed, remaining process time of each process chamber, historical process quality index, and equipment health score.
  3. 3. The multi-chamber vertical furnace for semiconductor industry thermal processing of claim 1, wherein the process space of the intelligent scheduling system comprises selecting a target process chamber for a target boat, planning a transfer path, and loading a set of preset process parameters.
  4. 4. A multi-chamber vertical furnace for semiconductor industry thermal processing according to claim 1 wherein the process intelligent scheduling system employs a dual delay depth deterministic strategy gradient TD3 algorithm and multi-objective optimization of throughput, process quality and energy consumption by a reward function.
  5. 5. A multi-chamber vertical furnace for semiconductor industry thermal processing as recited in claim 1, wherein the input vector of the LSTM neural network model comprises current residual gas concentration, chamber temperature, process gas partial pressure, gas flow rate, process duration, chamber material coefficient, and historical contamination accumulation.
  6. 6. A multi-chamber vertical furnace for semiconductor industry thermal processing according to claim 5 wherein said historical contamination accumulation is based on a weighted summation of residual gas concentrations over the past N process cycles, the weight in the weighted summation decreasing with process cycle.
  7. 7. A multi-chamber vertical furnace for heat treatment in the semiconductor industry as claimed in claim 1, wherein the gas contamination prevention and control system comprises the steps of inert gas purging, argon plasma purging and oxygen plasma purging in combination with vacuum pumping performed in sequence when the predicted value exceeds a preset threshold.
  8. 8.A multi-chamber vertical furnace for heat treatment in semiconductor industry as claimed in claim 1, wherein the bracket is composed of a cantilever fixed on the moving mechanism and a turntable arranged on the end of the cantilever, the turntable is uniformly distributed with a plurality of branches along the circumference, each branch can support and release or clamp the furnace door, and the turntable is driven to rotate by a motor or a revolving cylinder.
  9. 9. A multichamber vertical furnace for heat treatment in semiconductor industry as in claim 1 wherein said wafer boat is a vertically placed frame structure made of quartz or silicon carbide for safely carrying wafers at high temperature and keeping the wafers in accurate position, non-deforming, and preventing wafer sticking or slipping.
  10. 10. The multi-chamber vertical furnace for semiconductor industry thermal processing of claim 1, further comprising a main frame for supporting the process chamber and facilitating completion of the boat docking and offloading process.

Description

A multichamber vertical furnace for semiconductor trade thermal treatment Technical Field The invention relates to the field of semiconductor manufacturing equipment, in particular to a multi-chamber vertical furnace for heat treatment in the semiconductor industry. Background In the semiconductor manufacturing process, a vertical furnace is used as key heat treatment equipment and is widely applied to the process steps of oxidization, diffusion, annealing and the like of wafers. Along with the continuous shrinking of the feature size of semiconductor devices and the continuous increasing of the process complexity, higher requirements are put on the precision control, the production efficiency and the pollution prevention and control of heat treatment equipment. The existing vertical furnace technology mainly adopts a single-chamber structure, and a wafer boat bearing wafers is sent into a reaction chamber for heat treatment through a lifting mechanism. Chinese patent CN103673582B discloses a method for controlling the temperature of the loading zone in the process of lowering the boat in a vertical furnace apparatus, which reduces particle adhesion and wafer contamination by means of staged boat lowering control. Chinese patent CN118571775A discloses a furnace process control method, which improves the problem of uneven temperature distribution in the furnace by temperature pre-adjustment. Chinese patent CN117198931a proposes a vertical reaction furnace apparatus, in which two sets of furnace bodies share a set of wafer carrier processing unit by partition walls. Chinese patent CN114360997B discloses a multi-chamber cleaning method, in which a gas detection device is used to cyclically detect the cleaning state of each chamber. Chinese patent CN220169915U proposes a vertical furnace with an auxiliary furnace door structure, which realizes temperature control by closing a process tube through an auxiliary furnace door. However, the prior art still has the technical defects that firstly, the multi-equipment cluster scheme has the risk of interface contamination in the wafer transmission process, a perfect vacuum lock cannot be realized when the wafers are transmitted among different process equipment, the cavity is broken and the manipulator shuttles in the transmission process can cause the instantaneous contact of the wafer surface with an oxygen-containing and moisture-containing environment, a natural oxide layer is formed at a key interface or impurities are introduced, the electrical performance of a device is seriously deteriorated, and meanwhile, each independent process equipment needs independent preheating, process, cleaning and cooling periods, a large amount of non-increment time is accumulated, and the production efficiency is low. In addition, the single-equipment multi-step process scheme has the problems of process temperature conflict and gas cross contamination, the traditional vertical furnace has slow temperature rising and falling process, can not finish the process steps with mutually contradictory temperature requirements in the same flow, causes thermal budget to be out of control, and is difficult to completely remove precursor and byproduct residues when the reactive gases with different chemical properties are switched, so that the cross contamination is caused, and the purity and the electrical property of the film are affected. In addition, the prior art lacks an intelligent process scheduling and pollution prediction mechanism, can not dynamically optimize the production flow according to the real-time process state, and can not pre-judge and prevent and control the gas pollution risk in advance. Disclosure of Invention In order to solve the problems of interface contamination risk and low production efficiency of a multi-equipment cluster scheme in the existing semiconductor vertical furnace technology, process temperature conflict and gas cross contamination of a single-equipment multi-step process scheme, and irreconcilable contradiction among efficiency, compatibility and control precision caused by a 'one-cavity' natural mode, the invention provides a multi-cavity vertical furnace for heat treatment in the semiconductor industry, which realizes the improvement of interface quality and device performance, the enhancement of process compatibility and integration capability, the improvement of production efficiency and flexibility and the realization of accurate thermal budget and doping control. The invention provides a multi-chamber vertical furnace for heat treatment in the semiconductor industry, which comprises a plurality of mutually independent process chambers, a conveying mechanism, a process intelligent scheduling system and a gas pollution prevention and control system, wherein each process chamber is provided with an independent temperature control system and an atmosphere control system, the conveying mechanism comprises a bracket capable of rotating around a cen