JP2751666B2 - Semiconductor wafer thermal oxidation diffusion system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal oxidation / diffusion system for a semiconductor wafer provided with a gas suction / analysis mechanism inside a core tube of a thermal oxidation / diffusion furnace.

[0002]

2. Description of the Related Art In a conventional semiconductor wafer thermal oxidation / diffusion apparatus, only the flow rate of gas supplied to a furnace core tube is detected outside the furnace core tube. The impurities were detected by thermally oxidizing and diffusing a special semiconductor wafer for analysis and analyzing the surface of the semiconductor wafer before and after the treatment and the inside of the thermal oxide film. In addition, in order to determine whether the composition, mixing ratio, and concentration of the oxidized diffusion gas in the furnace are abnormal, a special semiconductor wafer for measuring the oxide film thickness and diffusion layer resistance is thermally oxidized and diffused, The resistance of the oxide film and the diffusion layer after the treatment was measured and compared with the measured values in a steady state.

[0003]

In this conventional semiconductor wafer thermal oxidation diffusion apparatus, the flow rate of the gas supplied to the furnace core tube is only detected outside the furnace core tube. The composition, mixing ratio, concentration, impurities, particles, etc., of the thermally oxidized diffusion gas inside the tube cannot be detected. There is a drawback in that it takes a lot of time and effort to thermally oxidize and diffuse the wafer and analyze it. In addition, the product is processed in spite of the occurrence of minute contamination and micro cracks and cracks in the furnace core tube, which are not recognized by the analysis, the film thickness measurement, and the layer resistance measurement. There were drawbacks.

It is an object of the present invention to provide a semiconductor wafer thermal oxidation diffusion system which solves the above-mentioned problems.

[0005]

In order to achieve the above object, a semiconductor wafer thermal oxidation / diffusion system according to the present invention comprises the steps of:
A furnace core tube for thermal oxidation diffusion comprising a furnace core tube internal gas suction pipe for sucking an oxidation diffusion gas from the atmosphere inside the furnace core tube;
Oxidizing diffusion gas inside the furnace core tube is sucked from the gas pipe inside the furnace core tube, and a gas concentration analysis mechanism inside the furnace core tube for analyzing the composition and concentration of the gas, and a gas concentration analysis mechanism inside the furnace core tube sucks the gas. Containing impurities contained in the oxidized diffusion gas inside the furnace core tube, the furnace core tube inside gas impurity analyzing mechanism for further analyzing the amount thereof, the furnace core tube inside gas concentration analyzing mechanism, and the furnace core tube inside gas. A thermal oxidation diffusion control operation mechanism for comparing the gas concentration and the amount of impurities detected by the impurity analysis mechanism with a steady state stored in advance to determine whether or not there is an abnormality; And an alarm generation safety mechanism for generating an alarm when it is determined that the thermal oxidation diffusion process is interrupted.

[0006]

According to the present invention, a steady state is maintained by automatically detecting the composition, mixing ratio, concentration, impurities, particles, etc. of the gas inside the furnace core tube.

[0007]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram showing one embodiment of the present invention.

In the figure, during the thermal oxidation diffusion process by introducing gas from the thermal oxidation diffusion gas supply pipe 2 and during a standby state before and after the thermal oxidation diffusion processing, a part of the gas in the atmosphere inside the thermal oxidation diffusion furnace core tube 1 is shown. Is sucked into the furnace core tube internal gas concentration analysis mechanism 4 through a plurality of furnace core tube internal gas suction pipes 3 attached at various positions in the furnace. The furnace core tube internal gas concentration analysis mechanism 4 analyzes the sucked furnace core tube gas and detects the composition, concentration, mixing ratio, and the like of the gas. Further, impurities such as heavy metals and particles in the gas are detected by the furnace core tube internal gas impurity analysis mechanism 5. The analysis data obtained by the furnace core tube internal gas concentration analysis mechanism 4 and the furnace core tube internal gas impurity analysis mechanism 5 is transferred to the thermal oxidation diffusion control operation mechanism 6. The thermal oxidation / diffusion control operation mechanism 6 stores in advance the gas composition, concentration and mixing ratio in the steady state, the allowable values of the number of impurities and particles contained in the gas, and the like. 4 and the analysis data transferred from the furnace core tube internal gas impurity analysis mechanism 5. As a result, when the atmosphere inside the thermal oxidation diffusion furnace core tube 1 is determined to be abnormal, an operation signal is transferred to the alarm generation safety mechanism 7.

The alarm generation safety mechanism 7 issues an alarm to notify the operator of the abnormality, further interrupts the process during the thermal oxidation diffusion process, automatically withdraws the semiconductor wafer from the furnace, and issues an alarm. Unable to start processing until the cause is resolved.

In the above-described embodiment, a steam oxidation furnace is considered. However, an embodiment using phosphorus diffusion or the like may be considered.

[0011]

As described above, the present invention constantly sucks and analyzes the thermally oxidized diffusion gas inside the thermal oxidation diffusion furnace core tube during and before and after the thermal oxidation diffusion treatment, and compares it with the steady state.・ Because of the judgment, the composition, mixing ratio, concentration, impurities, particles, etc. of the thermally oxidized diffusion gas inside the furnace core tube during processing can be detected. The conventional work of thermally oxidizing and diffusing and analyzing a special semiconductor wafer for measuring the resistance of a diffusion layer and the like becomes unnecessary, and the time and labor can be reduced. In addition, it is possible to detect a minute amount of contamination and minute cracks or cracks in the furnace core tube, which are not found by conventional analysis, film thickness measurement, and layer resistance measurement, thereby reducing a product abnormality.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal oxidation diffusion furnace core pipe 2 Thermal oxidation diffusion gas supply pipe 3 Furnace core internal gas suction pipe 4 Furnace core internal gas concentration analysis mechanism 5 Furnace internal gas impurity analysis mechanism 6 Thermal oxidation diffusion control operation mechanism 7 Alarm generation safety mechanism

Claims (1)

(57) [Claims] 1. A furnace core tube for thermal oxidation diffusion, comprising: a furnace core tube internal gas suction pipe for sucking an oxidation diffusion gas from an atmosphere inside a furnace core tube during a thermal oxidation diffusion treatment of a semiconductor wafer; A furnace core tube internal gas concentration analysis mechanism for sucking the oxidizing diffusion gas inside the furnace core tube from the internal gas suction tube and analyzing the composition and concentration of the gas; and a furnace core sucked by the furnace core tube internal gas concentration analysis mechanism. Impurities including particles contained in the oxidized diffusion gas inside the tube, a furnace core tube internal gas impurity analysis mechanism for further analyzing the amount thereof, the furnace core tube internal gas concentration analysis mechanism, and a furnace core tube internal gas impurity analysis mechanism The thermal oxidation diffusion control operation mechanism, which compares the gas concentration and the amount of impurities detected by the above with a previously stored steady state and determines whether or not there is an abnormality, is determined to be abnormal by the thermal oxidation diffusion control operation mechanism. If And a warning safety mechanism for interrupting the thermal oxidation diffusion process by generating an alarm on the semiconductor wafer.