JP2723509B2 - Diffusion furnace equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a diffusion furnace apparatus. [Prior Art] This type of diffusion furnace apparatus includes a furnace core tube for diffusion processing of a semiconductor substrate, and a loader mechanism for loading and unloading the semiconductor substrate into and from the furnace core tube. The substrate is carried in, subjected to diffusion processing of the substrate with desired impurities in the furnace core tube, and after the diffusion processing, the substrate is again carried out of the furnace core tube by the loader mechanism. Incidentally, the semiconductor substrate carried out of the furnace core tube is detached from the boat on which the substrate is mounted by automatic transfer, and transferred to the next step. Therefore, it is necessary to stop the semiconductor substrate at a predetermined position by the loader mechanism. Conventionally, in this type of diffusion furnace, the stop position of the semiconductor substrate after carrying out the semiconductor substrate is determined by visually checking the stop position of the loader mechanism. [Problems to be Solved by the Invention] In the conventional diffusion furnace apparatus described above, even if the stop position of the loader mechanism can be accurately determined, depending on the mounting state of the semiconductor substrate, the semiconductor carried out by the loader mechanism may be removed. The stop position of the substrate will not be accurate. As a result, the precision problem that the semiconductor substrate is displaced from the expected position at the time of automatic refilling, and the boat on which the semiconductor substrate on the fork of the soft landing diffusion furnace is expanded due to the expansion of the fork due to heat, the processing shifts, There is a problem that the semiconductor substrate on the boat shifts more and more as the cycle is repeated. An object of the present invention is to provide a diffusion furnace apparatus having a function of accurately stopping a semiconductor substrate carried out of a furnace at a set position. [Means for Solving the Problems] The diffusion furnace apparatus of the present invention includes a furnace core tube for diffusion processing of a semiconductor substrate, a boat on which the semiconductor substrate is mounted, and loading / unloading of the boat into the furnace core tube for diffusion processing. In the diffusion furnace apparatus having a loader mechanism for loading and unloading the semiconductor substrate into and out of the furnace core tube, the semiconductor substrate is disposed obliquely along the semiconductor substrate transfer path corresponding to the stop position of the semiconductor substrate. A light-emitting element and a light-receiving element, the light-emitting element and the light-receiving element being arranged such that an optical path thereof is shielded by a semiconductor substrate positioned at the head among the semiconductor substrates mounted on the boat, and A sensor for generating a drive control signal for the loader mechanism by detecting a semiconductor substrate positioned at the top of the semiconductor substrates mounted on the boat. You. Embodiment An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 7 denotes a furnace core tube, and a loader mechanism for supporting a boat 4 on which a semiconductor substrate 3 is mounted on a fork 5 and carrying the boat 4 into and out of the furnace core tube 7 outside the furnace core tube 7. 6 is provided. The loader mechanism 6 is moved left and right in the figure by the driving feed of the screw rod 6a. According to the present invention, a sensor S including a pair of the light emitting element 1 and the light receiving element 2 is disposed corresponding to the unloading stop position T of the semiconductor substrate 3 set outside the furnace core tube 7. When the semiconductor substrate 3 blocks the optical path 1 between the light receiving element 2 and the semiconductor substrate 3, the sensor S determines that the semiconductor substrate 3 has reached the stop position T, and issues a drive control signal for the loader mechanism 6 based on the signal. The driving is stopped. In the embodiment, the light emitting element 1 and the light receiving element 2 are arranged obliquely along the transport path of the semiconductor substrate 3, and the optical path l is controlled by the semiconductor substrate 3a positioned at the head of the semiconductor substrate 3 mounted on the boat 4 when unloaded. Is shielded from light. [Effect of the Invention] As described above, the present invention detects the position of the semiconductor substrate and determines the stop position of the semiconductor substrate, so that the semiconductor substrate can be moved regardless of the displacement of the loader mechanism or the displacement of the fork and the boat on the fork. There is an effect that the substrate can be accurately stopped at a predetermined stop position, and operations such as automatic transfer can be performed accurately.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing one embodiment of a diffusion furnace apparatus of the present invention. DESCRIPTION OF SYMBOLS 1 ... Light-emitting element 2, ... Light-receiving element S ... Sensor, 3, 3a ... Semiconductor substrate 4 ... Boat, 5 ... Fork 6 ... Loader mechanism

Claims (1)

(57) [Claims] A furnace core tube for diffusion processing of a semiconductor substrate, a boat on which the semiconductor substrate is mounted, and a loader mechanism for carrying the semiconductor substrate into and out of the furnace core tube by carrying the boat into and out of the furnace core tube for diffusion processing. A light-emitting element and a light-receiving element that are obliquely arranged along a transport path of the semiconductor substrate corresponding to a stop position of the semiconductor substrate, wherein the light-emitting element and the light-receiving element are mounted on the boat. The semiconductor substrate having the light emitting element and the light receiving element arranged such that an optical path thereof is shielded by a semiconductor substrate positioned at the head, and the semiconductor substrate positioned at the head among the semiconductor substrates mounted on the boat at the time of unloading A diffusion furnace device, comprising: a sensor that generates a drive control signal for the loader mechanism by detecting a load.