Abstract: A method of manufacturing a light emitting diode, which includes the steps of bringing a semiconductor substrate of p-type or n-type into contact with a growth solution at a high temperature and thereafter, lowering the temperature so as to form a monocrystalline epitaxial layer of the same type as the semiconductor substrate on the semiconductor substrate, subsequently, further lowering the above temperature to form a first monocrystalline epitaxial layer of a reverse type to the epitaxial layer on the epitaxial layer and then, cutting off the growth solution to form an epitaxial wafer as a result, a growth solution to contact the first epitaxial layer of a epitaxial wafer at a high temperature, and thereafter, the temperature is lowered to form a second monocrystalline epitaxial layer of the same kind and type as the first epitaxial layer on the first epitaxial layer.

Abstract: A method for producing a light-emitting diode provided with a pn junction of GaP containing nitrogen on an n-type GaP substrate, includes the steps of: forming an n-type GaP layer on the n-type GaP substrate by epitaxial growth by bringing the n-type GaP substrate into contact with an oversaturated melted Ga; forming an n-type GaP:N layer having a low n-type carrier concentration on the n-type GaP layer by epitaxial growth by bringing the melted Ga into contact with NH.sub.3 gas; and forming a p-type GaP:N layer having a carrier concentration almost equal to a carrier concentration of the n-type GaP:N layer on the n-type GaP:N layer.

Abstract: A game machine comprises hit flag counters which count up each hit request and count down upon the occurrence of each hit game. In these hit flag counters, if a hit cannot occur in spite of a hit request, the hit request is stored for the following games until the corresponding hit is obtained. A hit can be obtained only when the number of stored hit requests is not less than the number of inserted coins, so that the pay-out rate of the game machine is exactly controlled to be constant in totality.