semiconductor physics - Why n+ contact of p type Ge is 700um thick compared to p+ contact of n type Ge only 0.3um?

Whether the reason is as follows? Predominantly HPGe is p type. So compensation of large p type impurity requires more n+ contact. (700um) But n type Ge is made by doping of excess addition of n type impurity in p type HPGe. So n type impurity addition always slightly excess of p type impurity. Hence, slight excess n type impurity in n type HPGe requires, p+ contact with very less thickness. (0.3um)