Abstract: A slider member (30), at least covering a front surface part of a protection target device (40) disposed under a floor of a vehicle body (1) behind a sub-frame (20); and an installation member (50), disposed behind a rear end part (22) of the sub-frame (20) and installing the slider member (30) to the vehicle body (1) are provided. The slider member (30) has an inclined surface (31a) facing a front of the vehicle body (1) and inclined rearward and downward of the vehicle body (1). The installation member (50) has a reinforcement surface (51) formed at an inclination angle same as the inclined surface (31a) and abutting against the inclined surface (31a) from behind.

Abstract: A layer of GaAs.sub.1-x P.sub.x (0<x<1) is epitaxially grown on GaAs which is disposed in a reaction tube at a different location from the Ga source by maintaining the GaAs at a temperature range of from about 750.degree. C. to about 850.degree. C., maintaining the Ga source at a temperature higher than that of the GaAs, introducing As.sub.4 gas, PCl.sub.3 gas and H.sub.2 gas or AsCl.sub.3 gas, P.sub.4 gas and H.sub.2 gas into the reaction tube from the Ga source side, whereby said gases react with the Ga source and produce GaCl gas, and contacting said gases including the GaCl gas with the surface of the GaAs.